A Land Managers Guide to Prairies and Savannas in Michigan ... · A Land Managers Guide to Prairies...

A Land Managers Guide to Prairies and Savannas in Michigan:History, Classification, and Management

Prepared by:Ryan P. O�Connor

Michigan Natural Features InventoryP.O. Box 30444

Lansing, MI 48909-7944

For:Michigan DNR Wildlife Division

Landowner Incentive Program

September 30, 2006

Report Number 2006-18

Suggested citation: O�Connor, R. 2006. A Land Manager�s Guide to Prairies and Savannas in Michigan: History,Classification and Management. Report 2006-18. Michigan Natural Features Inventory. Lansing, MI.

Copyright 2006 Michigan State University Board of Trustees.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin,gender, religion, age, disability, political beliefs, sexual orientation, marital status or family status.

Cover photo: Oak barrens in Newaygo County, Susan R. Crispin, MNFI

TABLE OF CONTENTS

Acknowledgements ......................................................................................................................................................... 1

Introduction and Purpose .............................................................................................................................................. 1

Historical Overview of Prairies and Savannas ............................................................................................................ 2What was Michigan Like? Distribution of Prairies and Savannas circa 1800s ......................................................... 2Prairie vs. Savanna: Historical Context ...................................................................................................................... 2Changes circa 1800s to Present .................................................................................................................................. 5

Ecological Processes........................................................................................................................................................ 8The landscape context of fire ...................................................................................................................................... 8Extreme soil conditions .............................................................................................................................................. 8Fire and soil extremes in concert ................................................................................................................................ 8Altered ecological processes ...................................................................................................................................... 9

Fauna and Flora ........................................................................................................................................................... 10Fauna ........................................................................................................................................................................ 10Flora ......................................................................................................................................................................... 11

Prairie and Savanna Classification in Michigan ....................................................................................................... 13Rarity ........................................................................................................................................................................ 13Classification ............................................................................................................................................................ 13

Management Guidelines for Restoring Prairie and Savanna................................................................................... 18Nature�s tool: Prescribed fire .................................................................................................................................... 18The rest of the management toolbox: mowing, grazing, disking, and herbicides .................................................... 22

What Are Your Goals? ................................................................................................................................................. 27

Appendices .................................................................................................................................................................... 30

Literature Cited ............................................................................................................................................................ 57

List of Figures

Figure 1. Distribution of prairie and savanna communities circa 1800............................................................... 3Figure 2. Vegetation of Michigan circa 1800....................................................................................................... 4Figure 3. High-quality wet to mesic prairie communities present day .............................................................. 15Figure 4. High-quality lakeplain savanna and prairie communities present day ............................................... 16Figure 5. High-quality dry to dry-mesic savanna and prairie communities present day .................................... 17Figure 6. Typical ignition and burn pattern of a ring fire ................................................................................... 20Figure 7. Typical ignition and burn pattern of a back fire or back burn ............................................................. 21Figure 8. Typical ignition and burn pattern of a strip fire .................................................................................. 21Figure 9. Cut-stump application of herbicides ................................................................................................... 25Figure 10. Basal bark application of herbicides ................................................................................................. 26Figure 11. Girdling with a hatchet or chain saw ................................................................................................ 26Figure 12. Frilling with a hatchet ....................................................................................................................... 26Figure 13. Application of herbicide onto a girdle .............................................................................................. 27

List of Tables

Table 1. List of prairie and savanna community types found in Michigan ........................................................ 13Table 2. Prairie and savanna community distribution across a moisture gradient ............................................ 14Table 3. Changes in dominance of different groups of grasses and forbs in response to fire seasonality ......... 19Table 4. Commonly used herbicides in ecological restoration .......................................................................... 24Table 5. Comparison of prairie communities in Michigan (listed from wet to dry) .......................................... 48Table 6. Comparison of savanna communities in Michigan (listed from wet to dry) ....................................... 49

List of Appendices

Appendix A. Wildlife Species of Greatest Conservation Need occurring in prairies and savannas .................. 30Appendix B. Rare plants associated with prairie and savanna communities .................................................... 33Appendix C. Natural Community Descriptions ................................................................................................. 37

Prairies and Savannas in Michigan Page-1

INTRODUCTION & PURPOSE

This publication is a summary of information relatedto the history, classification, and management ofprairie and savanna communities in Michigan.Information has been synthesized from a wide varietyof sources, including peer-reviewed journal articles,practical handbook publications, published andunpublished field research, and historical andanecdotal accounts.

This publication is not intended to be a comprehensivestand-alone reference, but rather to serve as a user-friendly guide to prairie and savanna communities forland managers, other natural resource professionals,and non-professional naturalists and land stewards.Readers are encouraged to seek additional informationfrom publications listed in Recommended Readingsections as well as from cited literature.

The classification of ecological communities can bedifficult. Discrete bounds are placed aroundcommunities that occur along a natural continuum ofecosystem conditions and associated vegetation.Correctly classifying any particular site on the groundcan be difficult at best. Managing remnant sites iseven more difficult, especially when faced witheconomic, social, and political factors that may limitmanagement options. It is hoped that this guide willhelp address some of these issues, bridge the gapbetween technical and non-technical publications, andenable the reader to make informed, effective landmanagement decisions.

ACKNOWLEDGEMENTS

Funding for this project was provided by the Land-owner Incentive Program, Michigan Department ofNatural Resources Wildlife Division. I would like tothank Mark Sargent, Private Lands Biologist withDNR, whose passion for and knowledge of grasslandshelped conceive the idea for this publication, and JohnPaskus, Conservation Planner with the MichiganNatural Features Inventory (MNFI) who helped crystal-lize the project. I would also like to thank SusanTangora, Michigan LIP Coordinator, and Dan Kennedy,Christopher Hoving, Brian Piccolo, Terry McFadden,and Kevin Swanson, LIP Biologists. Their tireless workto improve wildlife habitat for rare and decliningspecies on both public and private land served as aninspiration and provided practical examples of thesuccesses and trials of on-going ecological restoration.In addition, they also provided valuable editorialcomments. Glenn Palmgren, Stewardship Ecologistwith the DNR Parks and Recreation Division, andSherri Laier, Stewardship Director for the MichiganNature Association, also shared their many years ofstewardship experience and provided additionalpractical examples of prairie and savanna restoration.I am also gratetful for Michael Kost and Josh Cohen,ecologists with MNFI, who provided significanteditorial suggestions that greatly improved this docu-ment. Moreover, I am indebted to them for theirextensive field work, literature reviews, and commu-nity abstracts, publications that greatly guided thehistory and classification portions of this document.I would also like to thank Vern Stephens of the DNR

Wildlife Division Private Lands Office, who lent hisvast knowledge of herbicides to the project. Thisreport could not have been completed without the helpof Suzan Campbell and Kraig Korroch, who bothhelped me adjust to the steep learning curves of Adobesoftware. Numerous individuals also provided imagesand photos to illustrate concepts and bring to life thebeauty and color of our plants, animals, and land-scapes. They include Christopher Hoving, BrianPiccolo, and Dan Kennedy of the DNR LandownerIncentive Program; Doug Landis of Michigan StateUniversity; John M. Randall of The Nature Conser-vancy; Chris Evans from the University of Georgia,James R. Allison of the Georgia DNR, and ElizabethCzarapata of the Wisconsin DNR, whose photos wereall provided via Invasives.org; Randall Heiligmannfrom Ohio State University Extension, Wayne R. Paulyof the Dane County Park Commission, Madison,Wisconsin; Merel Black of the University of Wiscon-sin-Madison and Kitty Kohout from the WisconsinDNR, whose photos were made available by theWisconsin State Herbarium; as well as past and presentMNFI botanists, ecologists, and zoologists SusanCrispin, Dennis Albert, Kim Chapman, MichaelPenskar, Michael Kost, Bradford Slaughter, GaryReece, Pat Comer, Jennifer Kleitch, and Mary Rabe.Finally, I would also like to thank MNFI administrativestaff, including Pat Brown, Lyn Scrimger, Sue Ridge,and Connie Brinson for their assistance with budgeting,account management, equipment, and vehicles, as wellas the printing and binding of this report.


HISTORICAL OVERVIEW OF PRAIRIES AND SAVANNAS

What was Michigan Like?Distribution of Prairies and Savannas circa 1800s

When the Midwest was settled by Europeans in theearly 1800s, the landscape was vastly different thantoday. Circa 1800, savannas occupied between 11 and13 million acres of the Midwest, and prairies covered asimilar or larger amount of the region. Currently,prairies and savannas now occupy just 1% and 0.02%of their respective former extent, a loss of over 99%(Nuzzo 1986, Kline 1997).

Although Michigan is generally thought of as a stateprimarily dominated by forest, prairies and savannasmade up a significant component of the circa 1800slandscape. Because of the state�s northerly latitudeand relatively abundant rainfall, prairies and savannaswere concentrated in areas that had difficultysupporting trees, and were found especially inlandscapes with frequent fires or in sites with eitherdroughty or very wet soils. The majority of prairiesand savannas were located in a broad swath stretchingfrom Cass and Van Buren counties in the southwest toOakland County in the southeast (Figure 1). Known asthe Kalamazoo and Jackson Interlobate, this regionwas located between lobes of glacial ice advancingfrom the Lake Michigan, Saginaw Bay, and Lake Eriebasins during the Pleistocene glaciation. When the icemelted between 10,000-15,000 years ago, it left behindlarge deposits of sands and gravels that historicallysupported prairie and savanna. Other importantregions in the state include the droughty and infertilesoils of the Newaygo Outwash (located primarily inNewaygo County but stretching north to the LeelanauPeninsula) and the extremely dry, fire-prone pinebarrens of the High Plains region centered aroundGrayling, as well as portions of the central UpperPeninsula such as the Shakey Lakes area and YellowDog Plains region.

Estimated distribution of prairies (black) and savannas(gray) prior to European settlement (Nuzzo 1986).

Michigan had over 2,000,000 acres of savanna circa 1800.Currently, only 8,000 acres remain, mostly on extremely

droughty soils in the northern portions of the state.

Prairie vs. Savanna: Historical Context

Currently, an emphasis is generally placed on prairie orgrassland planting. Historically however, savannaswere much more common in Michigan. In a 1932 soilsurvey of Branch County, the landscape was describedthus:

The so-called prairies were not entirelytreeless, but supported a scattered growth,consisting principally of bur oak [Quercusmacrocarpa],�but the tree growth was notsufficiently dense to prevent the growth ofheavy grass cover (Moon et al.1932, cited inChapman 1984).Savannas with prairie vegetation beneath a scattered oak

canopy were once common in Michigan.

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Figure 1. Distribution of prairie and savanna communities circa 1800, based on the General Land Office Survey,conducted 1816-1856. Prairie and savannas were concentrated in a band from Cass and Van Buren county in thesouthwest to Oakland county in the southeast. Other major regions include the Newaygo County area and the pinebarrens region in the north-central portion of the Lower Peninsula and central Upper Peninsula. Overall prairies andsavannas made up 7% of the landscape circa 1800, the vast majority of which was savanna.

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Circa 1800s Vegetation, statewide Portion of vegetation in

prairie or savanna

82%

15%

3%

1%

21%

2%

43%

26%

1%

5.8%

0.2% 7%

emergent wetland

shrub/forested wetland

wet prairie

upland prairie

savanna

inland water

hardwood forest

conifer forest

Lakes & Rivers

Wetlands

Upland forest

Prairie & Savanna

Figure 2. Vegetation of Michigan circa 1800. Prairies and savannas made up 7% of the total landscape. Of this,savannas comprised the vast majority (5.8% statewide). Wet prairie, which includes lakeplain prairies and prairiefens, comprised 1% statewide. Upland prairies, which include dry prairie in addition to mesic or tallgrass prairie,made up only 0.2% of the state total.

Historically, fire was the single most important processthat maintained savannas and prairies in an opencondition. Fire stimulated grasses and wildflowerswhile simultaneously limiting the growth of woodytrees and shrubs. The fire frequency of any given siteis difficult to determine and is based on factors such astopography, the amount and type of fuel, and naturalfirebreaks. The time between fires may have been asmuch as 20 years in the wettest systems, but annualfires were also common, as noted in several historicalaccounts.

The annual fires burnt up the underwood,decayed trees, vegetation, and debris in theoak openings, leaving them clear ofobstructions. You could see through the treesin any direction, save where the irregularity ofthe surface intervened, for miles around you,and you could walk, ride on horse-back, ordrive in a wagon wherever you pleased inthese woods, as freely as you could in a neatand beautiful park (Van Buren 1884 as quotedin Chapman 1984).

A summary of the General Land Office Survey,conducted in Michigan from 1816 to 1856 reveals thatsavanna and prairie occupied 7% of the state at thetime of European settlement (Comer et al. 1995).Savanna made up the vast majority of this openlandscape, accounting for 5.8% of Michigan�s naturalenvironment (Figure 2). By comparison, wet prairies(which include lakeplain prairies and prairie fens),made up only 1% of the state total, and upland prairies(which include dry or shortgrass prairie in addition tomesic or tallgrass prairie) made up only 0.2% of thestate total. Overall, savanna was more abundant thanupland prairie by a factor of nearly 30:1.

What is the difference between prairie and savanna?In general, a prairie is commonly described as a grass-dominated community with less than one tree per acre(Curtis 1959). Savannas range from having 4 to nearly50 trees per acre (a maximum of approximately onetree every ten meters) (Chapman 1984). Canopy coverestimates range from 5% to 60%, depending on thetype of savanna. As discussed below, however,savannas and prairies existed along a naturalcontinuum, with prairie grading into savanna andsavanna grading into woodland and forest.


While some lightning-strike fires certainly occurred,fires were also deliberately set by Native Americansfor a myriad of reasons, ranging from stimulatingberry and forage production to assisting with huntingby driving game, to maintaining open landscapes forease of travel to increased visibility and protectionfrom enemies. In addition to mentioning some ofthese benefits, Hoffman (1835) also describes theimportant process of fire burning into the surroundingwoods, creating a mosaic of habitat:

To-day, for the first time, I saw the meadowson fire. They are of vast extent, running farinto the woods like the friths on a lake; and aswild grass, which they supply in the greatestprofusion, furnishes the new settler with all thehay he uses for his stock, they are burnt overthus annually to make it tender. These firestraveling far over the country seize upon thelargest prairies, and consuming every tree inthe woods, except the hardiest, cause theoften-mentioned oak openings, socharacteristic of the Michigan scenery.(Hoffman 1835, as quoted in Chapman 1984).

As Hoffman observed, fires burning into the woodscreated a mosaic of prairies grading into savannas andsavannas grading into more closed-canopy forest.Changes in fire frequency would cause this mosaic toshift, with more frequent fires thinning savanna trees,and opening the forest canopy. Conversely, and farmore common following European settlement, lessfrequent fires allowed tree seedlings and stump-sprouting oaks (oak grubs) to fill in the prairie andrapidly turn the savanna into a closed-canopy forest.

Changes in Savannas and Prairiescirca 1800s to present

With the advent of European settlement, the changes tosavannas and prairies were radical and rapid. Siteswith loamy soil were among the first areas chosen forfarmland, and those savannas not converted toagriculture were often selected as sites for towns,college campuses, and cemeteries. Fire frequencydecreased as Native American populations declined,towns grew and the need to protect homes and cropsfrom wildfire increased. As more roads were built, thelandscape became more fragmented, and those firesthat did occur were far less widespread.

�To-day, for the first time, I saw the meadows onfire. They are of vast extent, running far into thewoods like the friths on a lake....

These fires, traveling far over the country, seizeupon the largest prairies, and consuming everytree in the woods, except the hardiest, cause theoften-mentioned oak openings, so characteristic ofthe Michigan scenery.�

-Charles Fenno Hoffman, 1835

Historically, fires that began in the open also burned intothe surrounding woods, creating a mosaic of savannasinterspersed with prairies.

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It is estimated that oak openings occupied 900,000 acres inMichigan circa 1800. The community has been almost

completely lost, with only three acres remaining in one known site.


Even by the 1870s this change was well under way, asdescribed by Hubbard 35 years after an 1837expedition near modern-day Pontiac in OaklandCounty with the renowned Michigan explorer DouglasHoughton:

The surrounding country seemed to our eyesfar enough removed from the gloomy morass[surrounding Detroit] which wild imaginationshad depicted it twenty years before. Itappeared to me the most beautiful the sun evershone upon. It was of the character thenbeginning to be classed as �openings,�chararacterized by a gravelly soil and a sparsegrowth of oaks and hickories. I speak in thepast tense, because, though the rural beauty ofthe country is still unrivaled, little remains ofthe original character of the openings. This isa result partly of the progress of cultivation,and partly of the thick growth of small timberthat has covered all the uncultivated portionssince the annual fires have ceased, which keptdown the underbrush (Hubbard 1872, fromChapman 1984).

The conversion from prairie and savanna to forest wasastonishingly rapid. In many cases the changeoccurred within decades (25 to 40 years) (Curtis 1959),with more mesic communities like bur oak plainsconverting even more rapidly (Abrams 1992, Packard1993). Often, this was due to the presence of oak�grubs,� oak trees made shrubby by being repeatedlytop-killed by frequent fires (Chapman 1984). Despitetheir lack of stature above ground, their root system

was extensive and could be more than one hundredyears old. Following even a brief cessation of fire,they sprouted and grew vigorously, rapidly changingthe renowned savannas into a young forest. As thetrees grew, they quickly shaded out the prairie grassesthat provided the fuel for frequent fires, furtherreducing fire frequency.

In addition to changing fire frequency, Europeansettlers also introduced livestock grazing to the prairieand savanna ecosystem. While grazing by buffalo andother large mammals did occur historically, grazingpatterns of cattle and sheep were much more intensiveand often concentrated in a confined (fenced) area.Grazing by livestock resulted in further reductions ofgrasses and forbs and, in addition to lack of fire andclosed canopy conditions, has contributed to the lowfloristic diversity often seen in savanna remnantstoday. Grazing also facilitated the introduction ofexotic weeds such as Kentucky bluegrass (Poapratensis) by disturbing the soil.

Savannas and prairies were also prone to invasion byother exotic, invasive species such as commonbuckthorn (Rhamnus cathartica) and autumn-olive(Elaeagnus umbellata), a problem that began in themid 1900s and has been accelerating ever since. Oftenplanted for wildlife cover or landscaping in the past,the bird-dispersed fruit of these shrubs quickly foundits way to savannas and prairie edges, as many edge-loving bird species preferentially perch on large open-grown oaks and disperse the seeds in droppings whenthey fly off. This can create an easily-observed spatialpattern of clusters of exotic shrubs beneath large oaks

�It appeared to me the mostbeautiful the sun ever shoneupon. It was of the characterthen beginning to be classed as�openings,� characterized bygravelly soil and a sparsegrowth of oaks and hickories. Ispeak in the past tense, because,though the rural beauty of thecountry is still unrivaled, littleremains of the originalcharacter of the openings.�

-Dr. Bela Hubbard, describingthe rapid conversion fromsavanna to forest on an 1872expedition with DouglasHoughton near Pontiac.

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in old fields. With numerous edges relative to theirsize, savannas and prairie remnants (often small andsurrounded by fencerows, woodlots, or forests) wereparticularly susceptible to invasion by exotic shrubs(Apfelbaum and Haney 1991). As invasives becameestablished, they had compounded negative effects. Inaddition to competing directly with native species theyalso reduced fire-prone fuels such as prairie grasses,decreasing fire frequency and intensity, leading to evenfurther declines in native species.

Many former savanna remnants have almostcompletely closed canopies today and form much ofthe oak �forests� we now find in southern LowerMichigan. It is estimated that only 0.02% of thesavanna originally found in the Midwest remains,declining from around 11 to 13 million acres to just afew hundred acres spread across a dozen states (Nuzzo1986). In Michigan, the loss of savanna is mostdramatic in the oak openings community, oncedescribed as being �so characteristic of the Michiganlandscape.� It has declined from an estimated 900,000acres to just 3, a loss of 99.9996% (Comer et al. 1995,Cohen 2004b). Tiny remnants and restorable pocketsalso likely exist, but the loss has been tremendous byevery possible accounting.

Many of the oak �forests� insouthern lower Michigan areactually remnants of former

oak savanna.

Of the 11 to 13 million acres of savannafound in the Midwest circa 1800,

only 0.02% remains.

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In southeast Michigan, the federally threatenedeastern prairie fringed orchid (Platantheraleucophaea) is largely restricted to growing inroadside ditches and lawn edges because so littleof its lakeplain priaire habitat remains.


ECOLOGICAL PROCESSES

The defining character of prairies and savannas is their opencanopy. With enough sunlight reaching the ground, prairie grassesand wildflowers flourish and provide the necessary structure andfood sources for the associated wildlife community. Withoutnatural processes to maintain an open canopy, trees and shrubsquickly dominate and as canopy cover increases, prairie andsavanna species decline and are replaced by more shade-tolerantplants, leading to a wholesale change in the entire community.

The Landscape Context of Fire

Fire is the one of the most important processes in maintaining anopen canopy of prairies and savannas, but it must be understood inthe context of the overall landscape. Fires burned more frequentlyin regions with a predominance of dry, gravelly soils, such as theinterlobate and high plains regions. Open wetlands that were a partof this landscape were often juxtaposed with oak savanna and whenthe upland burned, the wetland did as well. Thus soils and overallglacial geology are important landscape factors that influenced firefrequency. Dry, nutrient-poor sand and gravel soils of outwashplains and ice-contact landforms promoted far greater firefrequency than did the relatively rich, comparatively moistmoraines and till plains.

Extreme soil conditions

Soils can also affect canopy cover by limiting tree and shrub growthin extreme moisture and nutrient conditions. Droughty soils, whichare also often nutrient-poor, lack sufficient moisture during thegrowing season and result in slow tree growth and an overall sparsecanopy. Conversely, too much moisture also can inhibit tree andshrub growth. As tree roots grow they respire metabolically, aprocess that requires oxygen from air trapped in the soil pores.When soil is saturated, these pores are filled with water instead ofair and most trees are unable to grow. Many herbaceous plantshave specific adaptations that allow them to tolerate high waterlevels and thrive where most woody plants cannot. Thus bothextremely dry and wet soils limit tree growth and promote a moreopen canopy.

Fire and soil extremes in concert

Soil moisture and nutrient availability vary along a continuum; thegreater the extreme the greater the limiting effect on woody plantgrowth. In general canopies are naturally more open on the driestand wettest sites. As conditions become less extreme on thecontinuum, they have less impact on limiting canopy cover and firefrequency becomes more important in maintaining an opencondition. In mesic sites where soils are ideal for tree growth, fireis the only process that keeps back woody species and promotesprairie and savanna vegetation. When fires cease, these sites arethe first to fill in, followed by dry-mesic and wet-mesic sites, and

Fire is the one of the most importantprocesses that maintain prairies andsavannas.

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In mesic sites where soils are ideal fortree growth, fire is the only process that

keeps back woody species.

Fires burned more frequently in regions witha predominance of dry, gravelly soils, suchas the interlobate and high plains regions.Open wetlands that were a part of thislandscape were often juxtaposed with oaksavanna and when the upland burned, thewetland did as well.

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lastly by very dry and very wet sites with the most extremesoil conditions. This partially explains why mesic prairieand savanna are so rare in the state and comparatively drierand wetter prairie and savanna are more common. Otherreasons for this pattern include the fact that more mesicsites were better for agriculture and cities and towns oftendeveloped in close proximity.

Altered ecological processes

The alteration of ecological process is one of the primaryreasons prairies and savannas are so rare today relative totheir historical extent. Suppression of fires has had thelargest impact, but changes in soil moisture regimes canalso radically alter vegetative composition. For more thana century, open wetlands have been tiled, ditched, and filledin an attempt to make them more suitable to agricultureand development. At other sites, overuse of groundwaterhas been suspected of lowering the water table in adjacentgroundwater-fed prairie fens. Alteration of hydrologydirectly or indirectly affects plant growth and composition.Often, even a slightly lower water table makes a site dryenough for trees and shrubs to gain a foothold. Sites with adisturbed hydrology are also more susceptible to invasionby non-native species like glossy buckthorn (Rhamnusfrangula), narrow-leaf cattail (Typha angustifolia), andgiant reed (Phragmites australis). As trees and shrubsbegin to dominate, their greater leaf surface area alsotranspires and translocates more water than herbaceousplants, creating a feedback loop that further lowers thewater table and promotes more canopy closure.

In some systems such as lakeplain prairiesand savannas along the coast of the GreatLakes, the natural water level fluctuates.Periodic high and low water cyclesprevent dominance by any small group ofspecies for long periods of time, andcombined over time help create anexceptionally diverse community. Inmesic sand prairies, seasonal water levelfluctuations are the norm, with high waterin the spring followed by a drop in waterlevels and a seasonal drought in latesummer. Maintaining the process ofnaturally fluctuating water levels in thesesystems is just as critical as maintaining aconstant supply of groundwater in a fensystem. From a conservation standpoint,re-establishing proper hydrology may beas or more important than prescribed firein the restoration of some sites.

Glossy buckthorn (Rhamnus frangula)and other invasive species not onlyoutcompete native plants and eliminatewildlife habitat, but can also lower thewater table due to excessiveevapotransporation.

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Ditching, installation of drain tiles, and fire suppression have radically alteredecological processes that once maintained lakeplain prairies and savannas.


FAUNA AND FLORA

Numerous animals and plants require prairies andsavannas for their primary habitat. Many common aswell as rare species are specially adapted to thrive inthe diverse, dynamic environment. Due to the nearcomplete loss of these systems, however, many ofthese species have experienced drastic declines.Overall, prairies and savannas support a greaternumber of rare and declining species than any othersingle terrestrial habitat type in Michigan (Eagle etal.2005). For a complete list of rare species associatedwith prairies and savannas, please see Appendices Aand B.

Fauna

Prairies and savannas support all types of wildlife,including mammals, reptiles, birds, and insects. Somespecies are generalists and will utilize any suitablegrass-dominated habitat including both native prairie,planted prairie, and even exotic cool season grass-(brome) dominated fields. Examples of generalistspecies include grassland birds such as grasshoppersparrow (Ammodramus savannarum), meadowlarks(Sturnella spp.), and bobwhite (Colinus virginianus);mammals like prairie vole (Microtus ochrogaster);and reptiles such as black rat snake (Elaphe obsoletaobsoleta) and eastern hog-nosed snake (Heterodonplatirhinos).

Other species are more restricted in their habitatpreference and are only found in prairie and savannawith specific vegetation structure. For example,Henslow�s sparrow (Ammodramus henslowii) requireslarge blocks of open land (40 acres or more) and abuildup of thick grass litter. Other species, such as thepopular introduced game species ring-neck pheasant(Phasianus colchicus torquatus), thrive whereparticular plants like switch grass are abundant. Moreoften, the type of prairie and savanna determine whatspecies might be found there. For example, reptileslike eastern massasauga (Sistrurus catenatuscatenatus) and Kirtland�s snake (Clonophis kirtlandii)are usually associated with prairie fen and adjacenthabitat in southern Lower Michigan, while box turtles(Terrapene carolina carolina) are more likely to befound in upland oak savanna.

Insects comprise the largest group of prairie andsavanna fauna. Many are found only in very specifichabitats and are highly dependent on particular plantspecies. Butterflies are one of the most visible andcharismatic groups, and include exceptionally rarespecies like the Karner blue (Lycaeides melissasamuelis), a small butterfly found only in oak barrensand dry prairie edges with an abundance of lupine(Lupinus perennis), its larval host plant. Other specieslike the borer moths (Papaipema spp.) are also highly

CLOSE UP: WILDLIFE

Prairies and savannas support more rare and declin-ing wildlife than any other terrestrial habitat inMichigan. Threatened by decades of habitat destruc-tion, conversion of habitat to shrub and forestland,overcollection, and exploitation, they are one of theprimary focuses of land managers in numerouspublic agencies and conservation organizations.

They include charismatic reptiles like box turtles,which can reach 100 years in age. Once relativelycommon through the Midwest,many turtles are threatened bythe loss of sandy, open nestingareas and ensuing roadmortality as females go insearch of places to lay eggs.

Other species like the easternmassasauga rattlesnake have suffered from persecu-tion, despite their relatively docile nature. Michiganis one of the last strongholds in the nation for thisspecies, which inhabits a wide variety of communi-

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Eastern massasauga

Eastern box turtle

ties ranging fromprairie fens to pinebarrens and adjacenthabitats.

The Karner blue is afederally threatenedbutterfly that is foundprimarily in Michigan and Wisconsin. Larvae feedonly on wild lupine, a plant of the once-common oakbarrens. Due to the near complete loss of thishabitat, however, lupine and the Karner blue are nowoften restricted to road edges and utility rights-of-way, the only areas that remainpartially open. Fortunately,biologists are making greatstrides in the recovery of thisspecies by restoring oak barrenswith prescribed fire and byforming strong partnershipsbetween government agencies,NGOs, and private land owners. Je

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Karner blue butterflyon flowering lupine


specialized, with different species utilizing particular plantspecies. Examples include the blazing star borer (P. beeriana),Culver�s root borer (P. sciata), and Silphium borer (P. silphii).Many insects are much less visible, but no less unique andimportant to the prairie and savanna ecosystem. Invertebrateslike beetles, spittlebugs, leaf hoppers, grasshoppers, katydids,crickets, and spiders are also important parts of the diversity aswell as function of these systems, whether they act as mirco-herbivores to break down vegetation, predators helping to keepother insect pests in check, or just to serve as a food source forgame species like wild turkey.

Many insects are dependent on natural prairie remnants. Whilehighly mobile species like grassland birds can move to new areasafter a disturbance like fire or colonize newly planted grasslandson former cropland, many insects are restricted to tiny relictpatches of former habitat. Recovery from disturbances like firemay be slow; if fire consumes all available habitat, some speciesmay even be extirpated from the site, a process made more likelyby the loss of habitat and connectivity between remnant patches.Perhaps more significantly, remnant-dependant insects have notyet been found to colonize planted prairies, even after a half-century of careful stewardship and management and when theyare exceptionally high in plant diversity (Mlot 1990). For thesespecies, an emphasis on careful restoration and management ofnatural remnant prairies and savannas over planted sites iscritical.

Flora

Plants form the key structural and functional component ofprairies. Typically grasses and sedges form the dominant matrixof biomass, with a diverse mix of forbs scattered throughout. Insavannas, oaks are also critical in providing woody structure anda partial canopy cover. With quick-drying litter containingvolatile chemical compounds, both oak leaves and grasses andsedges provide much of the fine fuel needed to carry fire throughthe system. Likewise, both oaks and grasses are characterized byextremely deep roots (6 -12 feet or more) that stabilize andenrich the soil as well as help plants tolerate drought as well assoaking up large amounts of rainfall and minimizing surfacerunoff.

Like wildlife, plants of these systems vary in their distributionand abundance. Some, such as big bluestem (Andropogongerardii) and Indian grass (Sorghastrum nutans) can be found innearly every community type throughout the state. Others, likeside-oats grama grass (Bouteloua curtipendula, state threatened)were never common in Michigan and are restricted to isolatedhillsides and dry bowl prairies. Flora also likely differed betweenrelatively open prairies and the partially closed canopy ofsavannas. Although many of these savanna specialists can befound in limited amounts in treeless prairies, they likely weremuch more abundant filtered light conditions once found in

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Indian grass (Sorghastrum nutans)

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Big bluestem (Andropodon gerardii)

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Prairie wildflowers like black-eyed susan(Rudbekia hirta) are not only showy but providean important nectar source for rare species likethe poweshiek skipperling (Oarisma poweshiek).


savannas. Because virtually no high-quality remnantsites remain, determining which species are savannaspecialists is difficult, but may have included plantssuch as lupine, Culver�s root (Veronicastrumvirginicum), and woodland sunflower (Helianthusdivaricatus).

A lack of diversity of native plants is an increasingproblem in both natural and planted prairies andsavannas. Historically, all but the driest prairies andsavannas easily contained over 100 native species ofgrasses, forbs, and woody species. In a typical plantedprairie, diversity may be limited to ten native speciesor less, of which only one or two almost completelydominates.

Many natural prairie remnants are still high indiversity, but abundance has likely shifted over time.A lack of fire often leads to an over abundance of

dominant grasses and a decline of small-seeded, short-stature wildflowers. Invasion by trees and shrubs, aswell as livestock grazing has also led to drasticdecline, especially in former savannas. Non-nativespecies have also become tremendously problematic.In addition to competing for growing space, some,such as spotted knapweed (Centaurea maculosa), aresuspected of releasing allelopathic chemicals that killor inhibit the growth of native plants (Weir et al.2003).

CLOSE UP: PLANTS

Throughout the seasons, the flora of prairies andsavannas in Michigan is perhaps more diverse,showy, and characteristic than any other habitat inthe state. From the purple violets and phloxes ofspring, to the intricate orchids of summer, to the tall,waving amber-colored grasses of the fall, atremendous array of plant species graces our prairieand savannalandscape.

Many plants areindicators of remnantprairie and savannahabitat. They includeearly-floweringspecies like birdfootviolet (Viola pedata),found in drier sitesincluding oak openings and pine barrens, as well asplants that flower in mid-summer like black-eyedsusan, found in a variety of both wet and dryprairies, and hoary puccoon (Lithospermumcanescens), found primarily in dry sand prairie andoak barrens remnants.

Prairies and savannasare at their mostcolorful in latesummer and fall,when blazing star(Liatris spp.), golden-rods (Solidago spp.),and prairie grasses areat their peak.

Regardless of theirshape, size, and color,virtually all prairie and savanna plants are adaptedto and benefit from periodic burns. Without fire,woody species encroach, thatch builds up andsmothers small wildflowers, and seeds have noexposed mineral soil on which to germinate.Prescribed burns are increasingly being used tomaintain remnant prairies and savannas and ensurethese diverse parts of our natural heritage will notbe lost.

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A silver-spotted skippernectars on northern blazingstar (Liatris scariosa).

High-quality remnant prairies and savannas can easilycontain over 100 native plant species, making them some

of the most diverse natural communities in the state.

Hoary puccoon (Lithospermum canescens)

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Marsh blazing star (Liatris spicata), goldenrods (Sol-idago spp.), and prairie grasses after a prescribed burn.

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Birdfoot violet (Viola pedata)


Community Name

State

Rank

Global

Rank

Prairie

Dry sand prairie S2 G3

Hillside prairie S1 G3

Lakeplain wet prairie S1 G2?

Lakeplain wet-mesic prairie S1 G1?

Mesic prairie S1 G2

Mesic sand prairie S1 G1?

Northern wet-mesic prairie S1 GNR

Prairie fen* S3 G3

Wet prairie S2 G3

Wet-mesic prairie S2 G2

Woodland prairie S2 G3

Savanna

Bur oak plains SX G1

Lakeplain oak openings S1 G2?

Oak barrens S2 G2?

Oak openings S1 G1

Oak-pine barrens S2 G3

Pine barrens S2 G3

Table 1. Prairie and savanna community types found inMichigan with global and state ranks. A rank of S1 orG1 designates a community as critically imperiled inthe state or world, S2 or G2 as imperiled, and S3 or G3as rare and vulnerable. SX designates a state-extirpated community. GNR denotes a community hasnot yet been ranked on a global scale.

*Prairie fen is included due to its similar vegetativecomposition, though it is not considered a true prairiecommunity because it occurs in wetlands with organic(peat) soils rather than mineral soils.

PRAIRIE AND SAVANNA CLASSIFICATION IN MICHIGAN

Numerous types of prairie and savanna communitieshave been described in Michigan. Because many typeswere uncommon and were quick to be altered uponEuropean settlement, almost no objective historicaldescriptions of their original flora and ecology exist.Adding to the confusion, they have been drasticallyaltered over the past 200 years and little remains oftheir original extent and character. As a result they areoften poorly understood by many natural resourceprofessionals from a conceptual standpoint. Withoutan understanding of their characteristics andclassification, identifying similar communities fromone another in the field can be difficult at best with anuntrained eye. This overview is intended to outlineboth broad and specific differences between variouscommunities and give field personnel a resource toassist in identifying particular sites on the ground.

Rarity

Prairies and savannas are among the most endangeredecosystems in the world. Ecologists assign state (S)and global (G) ranks that correspond with the rarity ofspecies and communities, ranging from 1 to 5, with 1being critically imperiled and 5 being common andsecure from a state (S rank) or global (G rank)conservation perspective. Of the seventeen prairie andsavanna communities found in Michigan, all are ratedG3 or rarer, with many falling into the globallyendangered and threatened categories of G1 and G2(Table 1). Plants and animals with similar rating ofG1 and G2 are often legally protected and listed on thefederal endangered species list.

Classification

Prairies and savannas can be classified in part byoverall structure. As mentioned above, the number oftrees present can be used to distinguish prairies fromsavannas, with savannas generally having more than 1tree per acre (Curtis 1959). This equates roughly witha 5% canopy or more (assuming one tree per acre witha minimum crown diameter of ~50 feet). Keepingthese general guidelines in mind, it is also important toremember these communities often existed side by sideone another in a shifting landscape mosaic. With thecombined effects of more than a century of agriculture,grazing, and fire suppression, this shifting mosaic hasbeen radically altered, and remnant prairies may nowappear to resemble savanna or shrub land, andremnant savanna may appear nearly completelyforested. There is also an issue of scale. What mayappear today as a small remnant prairie is often just a

Of the seventeen prairie and savanna communitiesfound in Michigan, all are rated G3 or rarer, with

many falling into the globally endangered andthreatened categories of G1 and G2.


Wetlands Uplands

Moisture Wet Wet-mesic Mesic Dry-mesic Dry

Prairie type Wet prairie

Lakeplain wet prairie

Prairie fen*

Wet-mesic prairie

Lakeplain wet-mesic

prairie

Northern wet-mesic

prairie

Mesic prairie

Mesic sand prairie

Woodland prairie

Hillside prairie

Dry sand prairie

Savanna type Lakeplain oak openings#

Bur oak plains

Oak openings

Lakeplain oak openings#

Oak barrens

Oak-pine barrens

Pine barrens

Table 2. Prairie and savanna community distribution across a moisture gradient. Categories aregeneralized, and any given community may actually fall across multiple moisture conditions.

*Prairie fen is included due its similar vegetative composition, though it not considered a true prairiecommunity because it occurs in wetlands with organic (peat) soils rather than mineral soils.#Lakeplain oak openings can occur on both wet-mesic and dry-mesic sites.

small opening within a much larger former savanna.This was also the case historically, as most prairiesexisted as small pockets within a savanna landscape. Itis important to recognize both the current condition (i.e.closed canopy forest) as well as the historical condition(i.e. savanna) of any given site, especially in the contextof land management, restoration, and conservation.

Prairies and savannas can also be classified based on avariety of ecological characteristics. One of the mostbasic and universal characteristics is moisture regime.Prairies exist across a wide spectrum of moistureconditions, ranging from very wet to very dry (xeric)(Table 2). Likewise, savannas exist across a similargradient, ranging from wet- mesic to dry.

Communities are also classified by the glacial landformson which they occur. Some types occur only on specificlandforms, such as lakeplain prairies, which are limitedto the glacial lakeplain areas of Saginaw Bay, southeastMichigan, and portions of extreme west Michigan(Figure 3). Other communities are classified by their soiltype, as in mesic sand prairie. This differentiates it frommesic prairie, which shares a similar moisture regimebut has loamy soils. Many other communities, while notclassified by landform or soil, nonethelesscharacteristically occur only on sites with specific soiland landform conditions (Figures 4 & 5).

For a complete list of Michigan communities pleaserefer to Michigan�s Natural Communities: Draft Listand Descriptions, available online at http://web4.msue.msu.edu/mnfi/data/MNFI_Natural_Communities.pdf. All prairie andsavanna communities are briefly described inAppendix C: Natural Community Descriptions. Manyof the communities are also more thoroughlydiscussed in abstracts. Also available on the MNFIwebsite, they provide detailed information onecological characteristics, distribution, flora and fauna.Due to the ongoing development of these abstracts, thereader is encouraged to periodically check the websiteas more are added each year.

Recommended Reading:Prairies and Savannas in Michigan

Albert, D.A., J.C. Cohen, P.J. Comer, M.A. Kost,and J.B. Spieles. Natural CommunityAbstracts. [dates various] Michigan NaturalFeatures Inventory, Lansing, MI. Availableonline at: http://web4.msue.msu.edu/mnfi/pub/abstracts.cfm#Communities

Michigan�s Natural Communities: Draft list andDescriptions. 2006. Michigan NaturalFeatures Inventory. Lansing, MI. Availableonline at: http://web4.msue.msu.edu/mnfi/data/MNFI_Natural_Communities.pdf


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Figure 3. High-quality wet to mesic prairie communities present day, based on MNFI database. Note the clustering ofcommunities in the Jackson and Kalamazoo interlobate regions of southern Michigan (area shaded in gray).


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Figure 4. High-quality lakeplain savanna and prairie communities present day, based on MNFI database. In general,circular shapes represent prairie communities, while other shapes represent savannas. Note that all communities arelocated in glacial lakeplain regions (shaded in gray).


Figure 5. High-quality dry to dry-mesic savanna and prairie communities present day, based on MNFI database. Ingeneral, circular shapes represent prairie communities, while other shapes represent savannas.


MANAGEMENT GUIDELINES FOR RESTORING AND MAINTAINING PRAIRIE AND SAVANNA

Nature�s Tool: Prescribed Fire

The most effective tool a manager can use to maintain prairiesand savannas is fire. Historically, fire promoted the growth ofherbaceous plants while setting back woody trees and shrubs. Inaddition, fire has been shown to stimulate grass growth andimprove the browse nutrition of native warm season grasseswhile hindering exotic cool season grasses (brome, fescue, etc).Fire can also increase wildflower diversity, depending on thetiming and seasonality of the burn. Many orchid species respondexceptionally well to fire. For example, at a nature sanctuary insoutheast Michigan, the number of flowering state-threatenedwhite lady�s slippers (Cypripedium candidum) increased tenfoldfrom around 200 to over 2,000 after a prescribed burn.

Fire FrequencyHistorically, it is estimated that fires occurred anywhere fromannually to once every 20 years. Fire frequency varied accordingto community type, topography, fuel load and flammability, andweather. In general, sites in the mesic portion of the continuumburned more frequently than extremely wet or dry sites. Wet sitesmight only burn during extremely dry spells, and have the addedeffect of a high water table to limit growth of woody species.Similarly, the droughty soils of very dry sites would both limittree and shrub encroachment as well as slow the growth andaccumulation of sufficient fine fuels needed to carry a burn. Ingeneral, a one burn every 2 to 5 years would be appropriate tomaintain a high-quality remnant prairie or savanna. If a site isdegraded and has not been burned in many years, more frequentburns will likely be necessary at first to restore proper structureand balance of trees and shrubs to grasses.

Fire SeasonalityThe seasonality of a burn is one of the most important factors indetermining the effects of a fire. In general, fire has the greatestadverse impact on plants that are actively growing. For example,an early spring fire may vigorously burn off herbaceousvegetation and top kill shrubs, but because roots are full ofcarbohydrate reserves, they resprout vigorously. In contrast, iftop-killed by fire when root reserves are at their lowest in latespring burn or summer, sprouting may be significantly less(Richburg 2005).

Spring burns also have the effect of inhibiting actively growingweedy cool-season grasses and stimulating warm-season grassesand late-flowering forbs (asters, goldenrods, etc.) (Howe 1994,1995) (Table 3). However, spring fires also can decrease early-blooming wildflower species by burning up newly growing plantsand increasing competition by stimulating earlier growth ofwarm-season grasses.

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White lady�s slipper (Cypripediumcandidum), a state-threatened orchid,responds exceptionally well toprescribed burns.

Prescribed fire is the most effective tool landmanagers can use to maintain prairies andsavannas.

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The seasonality of a burn is one of themost important factors in determining

the effects of a fire. In general, firehas the greatest adverse impact onplants that are actively growing.


Time of fire Early spring (April-May)

Mid Summer (mid-July)

Late summer (Sept)

Fall (Oct – Nov)

Grasses and sedges Warm seasonW Increase Decrease No change Increase Cool seasonC Decrease Increase Decrease Decrease?

Forbs Early Flowering forbsE Decrease Increase Increase Increase? Mid-Flowering forbsM Decrease Increase? Increase Increase? Late-Flowering forbsL Increase Decrease Increase? Increase?

Legumes (Fabeceae)F Increase Increase? Increase? Increase

In contrast, summer burns reduce dominance of warm-season grasses and yield an increase in early and mid-flowering forbs, sedges, and cool-season grasses. Thiscan be beneficial because over time warm-seasongrasses often completely dominate and out-compete oreven eliminate other native species important forwildlife. Burns during mid-growing season (July) showthe greatest increase in forbs and decrease in warmseason grasses (Sparks et al. 1998). Late-growingseason (September) burns result in a more modestincrease in early and mid-season flowering forbs withlittle to no change in warm season grass dominance(Copeland et al. 2002). Legumes (e.g. lupine, bush-clovers (Lespedeza spp.), and tick-trefoils (Desmodiumspp.)), which are critical for some species of wildlife aswell as being important in fixing nitrogen in nutrient-limited soil show increased growth following any fire,in particular after burns in spring or fall (Coppedge etal. 1998).

Currently, most prescribed burns are conducted betweenlate March and early May when humidity is low, windsare light and fine fuels (grasses, sedges, oak leaves,etc.) burn readily without getting out of control.Occasionally, burns are also conducted in mid to latefall when plants have mostly senesced, but appropriateburn days with suitably low humidity and light windcan be limited. Historically, many fires in Michigan didoccur during spring or fall, especially if started byNative Americans. Lightning-strike fires were commonduring the summer as well, but were likely smaller insize. Very few summer prescribed burns are currently

Table 3. Changes in dominance of different groups of grasses and forbs in response to fireseasonality (Howe 1994, 1995; Coppedge et al. 1998; Sparks et al. 1998; Copeland et al. 2002).

W Examples include: big bluestem, little bluestem, Indian grass, and switch grass.C Includes native grasses such as Canada wild-rye, exotic grasses such as brome and fescue, as well as

sedges (Carex spp.) and rushes (Juncus spp.). Results are likely highly species-specific.E Examples include: black-eyed susan, ohio spider-wort.M Examples include: annual fleabane, milkweeds, yarrow, wild bergamot.L Examples include: goldenrods, asters, blazing stars.F Examples include: lupine, bush-clovers, tick-trefoil, leadplant.

Growing season fires may be best for controllingwoody shrubs and maximizing wildflower diversity.

Legumes such as lupine (Lupinus perennis) displayincreased growth following a prescribed burn.

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conducted, but may be very effective inencouraging early-flowering wildflowers andmaximizing biodiversity. Aiming for acombination of spring, fall, and even occasionalsummer burns is the best approach in mostsituations, since it mimics natural patterns and willlead to the most diverse and fully functionalsystem and provide habitat for the greatest rangeof species.

Impacts on Wildlife: Burn Completeness, IgnitionPattern, and TimingNever aim for a 100% burn of all prairies orsavannas at a given site. While some wildlifespecies are fire-adapted and can flee or recoverquickly from burns, other species can be severelyimpacted by fire. Of particular concern are speciessuch as turtles, snakes, and insects, including manyspecies of rare butterflies. Leaving unburnedrefugia as habitat for wildlife is an importantcomponent of habitat management, especiallywhere rare or fire-sensitive species are known tooccur. This can be accomplished by burning onlyhalf to two-thirds of an entire site or breaking upthe site into two or three burn units and onlyburning one unit in a given year. Alternatively, aburn can leave unburned patches scatteredthroughout the burn unit if weather conditions areless than ideal for a 100% burn. Either of theseapproaches helps enable fire-sensitive insects inparticular to recolonize burned areas from adjacentunburned patches (Panzer 2003).

The type of burn can have large impacts on thesurvival of semi-mobile wildlife such as snakesand turtles. Fast-moving head fires often overtakethese animals before they have an opportunity toseek cover. In contrast, back burns move muchmore slowly and give species, many of them fire-adapted, a chance to move into burrows or otherprotected areas.

Likewise, the pattern of ignition and resulting burnimpacts wildlife survival. In a typical �ring fire�prescribed burn, a back burn is ignited in thedownwind portion of the burn unit, followed byignition of the burn lines toward the wind directionmaking a flanking fire, and is finished by lightingthe upwind line, creating a head fire that pushesinto the center of the burn unit (Figure 6). Whilethis method is safe and time-efficient, it also trapsall but the most mobile wildlife. In several casestudies, numerous individuals of snakes andturtles, including massasauga and other rare

Figure 6. Typical ignition and burn pattern of a ringfire. (Courtesy Wayne R. Pauly, Dane County ParkCommission, Madison, WI.)

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Turtles and other wildlife can be killed when encircled in aring fire, while back burns or strip fires allow wildlife achance to escape.


species, have been killed in this manner.Alternative ignition patterns, such as back-burningthe entire unit (Figure 7) or lighting small stripfires (Figure 8) provide wildlife with a chance toescape the burn entirely or seek cover.

Finally, the timing or seasonality of prescribed firealso can have a great deal of impact on wildlife.For example, burning when wildlife is generallydormant, such as early spring or late fall has beenofficially recommended to minimize impacts toeastern massasauga (state special concern, federalcandidate species). However, other species, suchas insects over wintering in the duff layer, may bemore susceptible at this time of year. Borer mothsare one example. In early spring and late fall eggsare present in leaf litter, but in the growing seasonthey are burrowed safely underground in the rootsof host plants. Also of particular concern are theMitchell�s satyr (Neonympha mitchellii mitchellii)and Karner blue butterflies, both federallyendangered species. It is not yet known if and howthese species may be adapted to fire, and aconservative approach that follows Fish andWildlife Service guidelines is recommended ifworking in habitats occupied by these species.

In general, concern over wildlife impacts shouldnot prevent prescribed burning. A strict approachto leaving a particular percentage of unburnedrefugia is not usually necessary, but care should betaken to balance burn objectives while minimizingadverse impacts to wildlife. Overall, managersshould seek to manage and maintain the ecosystemwithout eliminating all habitat for grassland-dependent species.

Figure 8. Typical ignition and burn pattern of a stripfire. (Courtesy Wayne R. Pauly, Dane County ParkCommission, Madison, WI.)

Figure 7. Typical ignition and burn pattern of a backfire or back burn. (Courtesy Wayne R. Pauly, DaneCounty Park Commission, Madison, WI.)

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Burn objectives should balance the need to maintainthe ecosystem without adversely impacting wildlifepopulations, especially for rare species like thefederally endangered Mitchell�s satyr.


The rest of the management toolbox:mowing, grazing, disking, and herbicides

Though prescribed fire is usually the best tool froman ecological perspective, if it is not a viablemanagement option other alternatives mayaccomplish management goals. These optionsinclude, but are not necessarily limited to mowingor brush-hogging, grazing, disking, and sprayingherbicides.

Mowing or brush-hoggingIf seeking to simply reduce standing vegetation,mowing may be appropriate. The downside ofmowing is that if done repeatedly for several years,wildflower species may be eliminated from thesite. If a site is being invaded with shrubs or smalltrees, mowing may temporarily reduce the woodycompetition and allow growth of more grasses.However, unless stumps are treated with anherbicide, most shrubs and trees sprout vigorouslyif cut. This results in the woody species regainingsimilar dominance in just 1 or 2 years, and canlead to an even greater dominance if left untreatedfor several years.

Mowing or brush-hogging is best used inconjunction with another management option,such as prescribed fire. Conducting a late springor fall burn at a site a year or so after brush-hogging may provide secondary kill on resprouts.Cutting down dense shrubs may also allow morefine fuel to build up and carry a burn moreeffectively. If too large to cut down entirely, adense shrub thicket can also be opened up by brushhogging small areas into the interior, allowing the

next fire to penetrate the thicket and providegreater control.

Alternatively, brush-hogging could be followed byan herbicide treatment of resprouts, an approachthat has been used successfully in Indiana torestore large areas of formerly shrub-dominatedfen, wet prairie, and wet meadow. If working inwetlands, be sure the ground is well-frozen beforeusing mechanized equipment and consider usingsmall machines with tank-like treads (such as theBobcat-like Posi-Trac) that minimize impact tosensitive wetland soils.

GrazingGrazing with cattle or other livestock has beenused in some areas to reduce woody vegetationwhere using mechanized equipment or herbicidesare not appropriate. Short-term effects of grazingmay yield positive results, but the long-term effectsare mixed at best. Some of the downsides ofgrazing include the fact that animals will notpreferentially eat woody or exotic species, and theyoften avoid problematic thistles and thorny shrubslike autumn-olive, buckthorn, and multiflora rose(Rosa multiflora). Native plants, especiallywildflowers, may suffer an initial decline. Anotherissue is the potential for the introduction of newexotics, especially if livestock manure containsweed seeds from hay or plants eaten at other sites.In wetlands, trampling of sedge tussocks thatprovide critical habitat for other plants andanimals is inevitable. As tussocks recover, theyprovide an ideal habitat for shrub seedlings, andwhen grazing ceases, shrubs quickly take overformerly herbaceous wetlands, making thesituation worse than prior to grazing (Middleton2004).

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Mechanical equipment like a treaded bobcat with a brushhogattachment can quickly clear thickets of shrubs.

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Livestock can be used to set back unwanted shrubs, butbecause they also eat and trample native species their use inhigh-quality natural areas should be avoided.


Rotational grazing in large upland grasslands100 acres or more may yield a better outcome,especially when combined with other tools likeprescribed burning. Isolating livestock on only aportion of the site helps to control shrubs as wellas reduce dominance of grasses and thereforeincreases wildflower diversity. The need formovable fences can be eliminated by burning aportion of a site (approximately 1/3) every year.Because the flush of new grass growth is morenutritious and palatable than in the unburnedportion, grazers naturally congregate and spendthe vast majority of their time grazing in thenewly burned area (Jamison et al. 2005).Grazing on grasses and localized tramplingexposes mineral soil much the way buffalo did inpre-European times, allowing wildflowers toflourish the following year when livestock moveon to a newly burned portion (Fuhlendorf &Engle 2001). Continued over time, diversity ismaximized as sites are burned & grazed (year1), recover with a flush of wildflowers (year 2),and return to grass dominance (year 3).

Disking or plowingWithout fire or other disturbance, a thick sod ofnative or non-native graminoids can form andcause a decline in diversity. A disk or plow canbe used to lightly break up thick sod and betterfacilitate interseeding with other grasses orwildflowers. This approach carries significantrisk, however, since the exposed mineral soilprovides an ideal habitat for weeds and exoticspecies. Disking also destroys clump-forminggrasses and sedge rhizomes, and may severelyimpact wildflowers growing from bulbs orcorms. Additionally, any soil disturbance onhillsides should be strictly avoided, as it maycause erosion.

In most cases, disking probably carries morerisks than benefits unless the site is completelydominated by exotic grasses or other weeds. Atmost remnant sites, one or two years ofprescribed fire will similarly reduce sod andprovide microsites for interseeding without therisk of introducing exotics with large-scale soildisturbance. Burning in summer or fall may domore to reduce growth of sod-forming warmseason grasses than a spring burn; a late springburn may more effective for reducingPennsylvania sedge (Carex pensylvanica).

Herbicides: TypesOnce rejected by many restorationists for health andenvironmental concerns, selective use of herbicides isnow considered an essential tool to managing andrestoring unique habitats. There are a wide variety ofchemicals available to managers, ranging fromherbicides that kill all green plants (such asglyphosate) to those that target only broadleaves(triclopyr; 2-4, D), to those that are more selective(imazapic, also known by the trade name Plateau®).Some formulations are approved for use in andaround wetlands, while others are strictly labeled foruse in uplands. For example, glyphosate iscommonly mixed with an oil-based surfactant that istoxic to amphibians, and standard formulations suchas RoundUp® should never be used in or near water,including ponds and small streams (Relyea 2005,Monsanto Co. 2001). Alternative formulations (suchas Rodeo® or Aquastar®) mix the active chemical in awater-based solution which minimizes harm to fishand wildlife.

When choosing an herbicide, always select achemical and a concentration that minimizes harm tonon-target plants and animals while still providingeffective control of the target plant species. Alwaysread and follow the label completely, which specifieswhat the herbicide can and cannot be used to controland provides specific direction for use. Additionally,an herbicide applicator�s license is usually requiredfor anyone applying herbicide as part of their job(private landowners applying unrestricted, over-the-counter herbicides to their own property are exempt).To apply for an applicator�s license or to find a list ofcertified applicators in your area, contact theMichigan Department of Agriculture or visit http://www.michigan.gov/mda. For a list of commonlyused herbicides in restoration, please see Table 4.

Herbicides: Methods of ApplicationDifferent means of application are available also, andmay be more or less appropriate depending on theproblem and goals of the manager. These include,but are not necessarily limited to foliar spraying, cut-stump application, basal bark application, drill andfill, and other variations. These methods aredescribed in brief below. If actually applying any ofthe methods in the field, more detailed informationshould be sought from a more thorough publicationsuch as The Weed Control Handbook by The NatureConservancy or by consulting an expert in naturalareas restoration.


Herbicide

Brand Name

Examples

Typical

use Target Species

2006 Cost/acre

(broadcast) Notes

2,4 D Navigate® Class

®

Weed-Pro®

Justice®

foliar broadleafs; doesn't

kill grasses

generic: $3.95 Inexpensive and common herbicide used for over 50

years. Mobile in soil. Petroleum-based formulations

can volatize and drift above 75 degrees F.

Clopyralid Reclaim®

Curtail®

Transline®

foliar broadleafs,

especially spotted

knapweed

Transline: $44.15 Highly selective herbicide developed as an alternative

to picloram. Mobile in soil.

Fluazifop-p-

ButylFusilade DX

®

Fusion® Tornado

®

foliar cool season grasses Fusilade DX: $29.10 Toxic to most grasses except annual bluegrass and all

fine fescues.

Glyphosate RoundUp® Rodeo

®

Accord®

Aquamaster®

foliar,

cut-stump

virtually all actively

growing species

Glypro Plus: $5.73

Aquamaster: $7.75

RoundUp Pro: $10.46,

$0.25/oz (cut stump)

Little to no soil activity, binds to soil particles. The

surfactant used in RoundUp and similar products is

highly toxic to aquatic organisms, always use wetland

formulations near water.

Imazapic Plateau® Journey

®

Cadre®

pre-

emergent

varies by species Journey: $8.45 Degree of control depends on selectivity of individual

species.

Imazapyr Habitat®

Arsenal®

foliar grasses &

broadleafs

Habitat: $37.75 Long half-life (up to 141 days). Provides long-term

total vegetation control. Especially used for

Phragmites, cattail, and reed canary grass.

Picloram TordonK® cut-stump broadleafs, vines,

and woody plants

$0.28/oz (cut stump) Environmental persistence and high soil mobility, can

kill adjacent trees via root contact, potential for

groundwater contamination.

Sethoxydim Poast® foliar grasses Poast: ~$15.00 Rapid degradation (5 day half-life, hours in sunlight)

can limit effectiveness.

Triclopyr Garlon4®

Garlon3A®

foliar,

cut-stump,

basal bark

broadleafs; doesn't

kill grasses

Garlon 3A: $7.88

Garlon 4: ~$13.50,

~$0.30/oz (cut stump,

basal bark)

Commonly used herbicide. Garlon 4 is for use in

uplands, but can volatize and drift above 80 degrees F.

Garlon 3A is for use in wetlands.

Table 4. Commonly used herbicides in ecological restoration. Adapted from: Tu et al. 2001. Weed Control MethodsHandbook. The Nature Conservancy.

Foliar sprayingFoliar spraying is one of the most commonly-usedapplication methods, and simply involves sprayinga diluted mist of herbicide onto the foliage of aplant. In situations where invasive plantscompletely dominate, this can be very effective.However, where weeds are more scattered andinterspersed with desirable natives, it can oftenresult in significant damage to non-target plants,unless done with extreme care or in situationswhere damage can be minimized. Such casesmight include plants with a very dense canopy thatwill intercept all of the chemical, or spraying over-wintering rosettes like garlic mustard (Alliariapetiolata) in late fall or very early spring whenmost other plants are dormant. Foliar spraying isonly effective when plants are green and activelygrowing. For most species this is spring throughfall, but plants that stay green year-round may betreated at any time as long as the air temperature isabove 32 degrees Fahrenheit.

Because it stays green year-round, garlicmustard (Alliaria petiolata) can becontrolled by spraying rosettes withherbicide in late fall and early spring whenmost other plants are dormant and areunlikely to be harmed.

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A variation of foliar spraying that targets specific plantsis wicking. A cloth or cotton glove worn over top of achemical-proof rubber glove is soaked with herbicide andthen swiped over the stem of individual plants. Thoughthis practice is very labor-intensive, it virtually eliminatesthe risk of overspray and non-target damage and may beappropriate in high-quality natural areas with fewinvasives.

Cut-stump applicationCut-stump application is also commonly used in naturalareas management and involves first cutting down ashrub or small tree and then spraying or dabbing aconcentrated dose of herbicide onto the cut stump, whichkills the root and prevents resprouting (Figure 9).Though it is the most effective way to eliminateespecially hard-to-kill woody species like buckthorn andautumn-olive without killing non-target plants, it is alsovery labor intensive. Traditionally, when treating a multi-stemmed shrub or clone every single stem was cut andherbicided to prevent resprouting. However, recentresearch suggests that entire multi-stemmed clones ofcommon buckthorn can be killed if only the largest stemin the clone is cut (or girdled) followed by an applicationof concentrated herbicide (Pergams and Norton 2006).Because only one stem of a large clone must be treated,significant time, effort, and money are saved. It is notknown if this approach works shrub species other thancommon buckthorn, but experimentation and carefulresearch on this topic is encouraged.

Dabbing herbicide onto cut stems can be difficult. Stafffrom The Nature Conservancy have designed anapplicator constructed from PVC pipe and a sponge thatis simple but effective. Design and use instructions canbe found online at: http://tncweeds.ucdavis.edu/products/handbook/22.PVCapplicator.pdf.

Cut-stump application should not be used at the height ofspring when plants are flushing, since rapid upwardsapflow prevents the chemical from being draw downinto the roots. Unlike foliar spraying, cut-stumpapplication does not require a plant to be activelygrowing and can be done nearly year-round, as long ascold temperatures don�t cause the herbicide mixture tofreeze on the stump. If using glyphosate, stems should betreated as soon as possible after cutting, ideally within 5minutes. If using triclopyr, prompt application is lesscritical.

Figure 9. Cut-stump application of herbicides.

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Shrubs that are cut will resprout vigorously unlessthe stumps are treated with an herbicide.

Applying herbicides to cut stumps with aPVC applicator is a labor-intensive butvery effective means of controllinginvasive species in natural areas.

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Basal-bark applicationBasal-bark application has long been used in forestryoperations and is gaining popularity with other landmanagers. It can be used selectively on individual treesand shrubs without the labor-intensive process of cuttingthe stem. A chemical such as triclopyr (Garlon4®) mixedwith oil is sprayed around the entire lower portion of anuncut woody stem (Figure 10). Stems must be six inchesor less in diameter for basal bark spraying to be effective.Traditionally, diesel fuel was used as the carrier oil, butthis carries significant risk to non-target plants as well asanimals. In natural landscapes, a generic, non-toxic,bark-penetrating oil can be used instead and yields equallyeffective results. Commonly-used premixed formulationssuch as Pathfinder II® are also commercially available.Because of the surfactant oils used, basal-bark treatmentsshould never be done in or near wetlands. It should benoted that basal bark treatment may not be equallyeffective for all species, as a recent study revealedsignificant sprouting of common buckthorn six monthsfollowing treatment (Pergams and Norton 2006).

Drill and fill / GirdlingDrill and fill is a method of killing large trees and shrubswithout cutting them down. A small hole is drilled at anangle down into the stem and concentrated mixture ofherbicide is placed into the hole, allowing it to soak intotree. Though seemingly quick and efficient, it is seldomused by natural areas managers except perhaps to treatlarge clones of trees that might otherwise resprout, suchas black locust (Robinia pseudoacacia) or tree-of-heaven(Ailanthus altissima). From a practical standpoint, thestems of the shrub or tree must be sufficiently large todrill into, making it impractical for smaller shrubs ormulti-stemmed clones that contain young sprouts.

Girdling (Figure 11) can also be used in combination withherbicide in a similar fashion, as can frilling. Frilling isaccomplished by using a hatchet to completely encirclethe stem with deep notches that peelback the bark and cambium withoutcompletely removing it from the tree(Figure 12). Following girdling orfrilling, the notch is filled withherbicide (Figure 13). A recent studyon shrub control methods showedgirdling combined with herbicides tobe equally effective as cut-stumpherbicide on large common buckthorn3 to 15 inches in diameter (Pergamsand Norton 2006).

Figure 11. Girdling with a hatchet (left)or chain saw (right).

Figure 12. Frilling with a hatchet.

Figure 13. Application of herbicideonto a girdle.

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Common buckthorn(Rhamnus cathartica)

Figure 10. Basal bark applicationof herbicides.

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There are several tools that can help determine thepotential for restoration at a site. Vegetation circa1800s is an excellent source of information on theformer distribution of prairies and savannas, and iseasily accessible in both paper and digital (GIS)form. This data is best used at the scale of aregion, county, or township, because it is compiledfrom GLO survey data based primarily alongsection lines (each one mile apart), althoughsurveyors did note when they cross large expansesof prairie.

The second primary source of information usefulin assessing restoration goals is the vegetation atthe site itself. The presence of large open grown�wolf trees� in an otherwise young forest can be asign of former savanna. Additionally, the presenceof prairie grasses and forbs in an oak forest likelyindicates a restorable savanna. A small stand ofprairie vegetation surrounded by shrubs or forestmay actually be a remnant pocket of prairie withina much larger former savanna. For moreexamples and an on-the-ground key to assessingrestoration options, please refer to the TallgrassRestoration Handbook (Packard 1997). Ingeneral, it is best to start with the highest quality

WHAT ARE YOUR GOALS?

area and work outwards, gradually enlarging thetarget restoration area as time and resources allow.

Goal: Maintenance of a high-quality remnantIf managing a site that already has an idealmixture of grasses, forbs, and trees and shrubs,conducting burns every 3-5 years is appropriate inmost cases. This should be frequent enough tomaintain a dominance of grasses and sedges whileallowing a diversity of wildflowers to thrive. Froma habitat perspective, it provides cover for wildlifethat prefer built up thatch, such as the state-threatened Henslow�s sparrow, as well as bareground and new growth for browse in freshlyburned areas.

Goal: Reducing native or invasive shrubs in aremnantIn most remnant sites, shrub invasion by bothnative and non-native species has become a majorproblem due to fire suppression. If there issufficient fine fuel to carry a fire, conducting aprescribed burn is often very effective. Burn latein the spring, mid summer, or early fall tomaximize shrub kill and limit resprouting. Rootreserves, the source of energy for resprouts, are attheir lowest when shrubs are flowering and fruiting

CLOSE UP: INVASIVE SPECIES

Exotic invasive species are one ofthe primary issues facing landmanagers today. Often introducedfrom Europe and Asia, theyoutcompete native species andwreak havoc on natural ecosystemsby growing rapidly, seeding prolifi-cally, reproducing vegetatively, andeven releasing toxic chemicals intothe soil. Biological controls that keep them in checkin their native range are often absent in the U.S.

There are several ways of controlling invasives. Oneof the most effective is to restore disrupted ecologi-cal processes, such as returning fire to the landscapethrough prescribed burning or restoring hydrology inwetland systems.

Mechanical control, either by cutting or pulling byhand or with larger equipment is also effective,especially when infestations are of sufficient size thatprescribed burning alone is ineffective.

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Autumn-olive (Elaeagnus umbellata)cannot be controlled by fire alone.

Cutting is more effective when com-bined with chemical control, withherbicides either applied to the cutstump or in a foliar spray to resprouts.Timing herbicide applications to hittarget species when they are mostsusceptible while minimizing impactto native species is critical.

Biological control agents have alsobeen effective in controlling some species like purpleloosestrife (Lythrum salicaria), but years of extensivecareful testing are required to ensure agents don�tcause other negative impacts.

Swallow-wort (Vincetoxicum spp.) is arapidly spreading new invasive in Michigan.

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(Richburg 2005). Both back burns as well as vigorous head firescan provide effective kill. Consider burning the same unitseveral years in a row, especially if shrubs resprout. Largershrubs and trees are often only weakened by an initial fire; it isoften the second or third fire that causes mortality. It isimportant to note that fire does not impact all species equally. Aburn may set back dogwoods and small diameter buckthorns, butit is generally ineffective at controlling large buckthorns andautumn-olive.

If burning fails to control shrubs or is not a feasible option, usecut-stump application of herbicides to remove specific shrubs orsmall trees. Brush can be scattered if it is limited in quantity, orpiled and burned in winter to minimize soil damage. If the siteis moderate to low in quality, and there is less risk of herbicidedamage to non-target plants, consider basal bark applicationwith triclopyr. It kills broadleaf shrubs and forbs, but will notharm grasses and sedges. Both cut-stump and basal barkapplication can also be used in conjunction with prescribed fireto control specific large or hard-to-kill shrubs such as glossybuckthorn or autumn-olive.

Finally, a more industrialized approach to reducing shrubs maybe to use large mechanized equipment such as a brush hog,Positrack, HydroAx. Be aware that many shrubs and small treeswill resprout. Stumps are often shattered by the massive blades,making them nearly impossible to treat with traditional cut-stump herbicide applications. Additionally, it is often difficult toget equipment back into an area for follow-up treatment sincethe shattered stems can easily puncture tires, though resproutscan be treated by hand with a backpack sprayer. New equipmentlike the Brown Brush Monitor simultaneously cuts and appliesan herbicide to stems, which should reduce resprouting. Despitedrawbacks of where and when it can be used, mechanizedequipment may be the most efficient and cost-effective option ifworking to restore large areas.

Goal: Restoring a closed-canopy oak woodland into savannaMany of our oak woodlands are actually former savannas thathave closed in due to fire suppression. When evaluating apotential savanna restoration site, it is important to look for twokey components: 1) presence of open-grown or �wolf� oak treesand 2) presence of herbaceous prairie or savanna species in thegroundcover (see community descriptions for examples). Thelatter is often more critical to a successful savanna restoration.

It is important to keep in mind that it took several decades forsites to become degraded and it may take equally long to restorethem. Quick fixes often backfire. If aiming for a 30% canopy,cutting out the other 70% of the trees may lead only to a largepatch of brambles. A better approach might be to gradually thinthe canopy while conducting prescribed burns to stimulate theherbaceous layer. Oak leaves burn readily in both spring andfall, and are sufficient to carry a fire at most sites with a

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A site will likely respond well to savannarestoration if prairie grasses, sedges, and forbsare still present beneath the oak canopy.

Many of our oak woodlands are actuallyformer savannas that have closed in

due to fire suppression.

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�Wolf trees�, or open grown oaks, mayindicate a forest is actually a remnantsavanna that may benefit from restoration.


dominant oak canopy. In some cases,cutting trees may not even be necessary,since even large trees of red maple (Acerrubrum) and black cherry (Prunus serotina)will be killed by fire if sufficient fuel ispresent to burn repeatedly.

One of the most effective ways to restoresavanna might be to allow a fire on anadjacent prairie to simply burn into thewoods. The intense flames near the prairiewill cause greater tree mortality on the outeredge of the savanna, creating a �feathered�edge over time. Several yards into thewoods, fuel load and flame heights willquickly diminish, having less of an effect ontrees, and creating a more natural spatialgradation from prairie to savanna to closedcanopy forest. Additionally, allowing firesto burn into adjacent upland woods alsominimizes the need for large firebreaks.Instead of a disc or plow line, two tracks ortrails may be sufficient burn breaks due to lowerflame heights. In the woods, a leaf blower or handrake can be used to quickly clear a small firebreakdown to bare soil.

Goal: Control of exotic grasses and wildflowersExotic grasses and wildflowers are problematic inboth natural remnant prairies as well as plantedgrasslands. Specific techniques for controllingunwanted plants differ depending on the targetspecies. A late spring prescribed fire can be veryeffective in reducing cool season grasses likebrome and fescue, especially if native warmseason grasses are present to provide competition.For spotted knapweed, a late spring, very hot firehas provided effective control at some sites.However, knapweed may only be stimulatedfollowing a low-intensity, relatively cool fire.Some invasive plants like white sweet clover(Melilotus alba) have a large seed bank andrespond vigorously to fire the season following theburn. However, since this biennial only produces alarge bushy rosette the first year, it can besuccessfully controlled with back to back burns.Knowing the biology of any problem species is ofutmost importance when assessing control options.

Herbicides can also be used to control weeds, butcare must be taken to avoid indiscriminantspraying where other desirable species will also bekilled. Imazapic (Plateau®) has been widely usedto help establish grassland planting because it kills

troublesome weeds without harming most warm-season grasses and selected wildflowers. Otherherbicides like clopyralid (Transline®) areespecially effective in controlling spottedknapweed but do not harm grasses and sedges.Likewise, triclopyr (Garlon®) and 2-4, Deffectively control broadleaf plants withoutharming graminoids.

RECOMMENDED READING: MANAGEMENT

Czarapata, E.J. 2005. Invasive Plants of the UpperMidwest: An Illustrated Guide to Their Identificationand Control. The University of Wisconsin Press,Madison, WI. 215 pp.

Packard, S. and C.F. Mutel, eds. 1997. The TallgrassRestoration Handbook for Prairies, Savannas, andWoodlands. Island Press, Washington, D.C. 463 pp.

Tu, M., C. Hurd, and J.M Randall. Weed ControlMethods Handbook: Tools and Techniques for Usein Natural Areas. The Nature Conservancy. http://tncweeds.ucdavis.edu/handbook.html Version date:April 2001.

Various authors: Element Stewardship Abstracts [onthe control of invasive species]. The Nature Conser-vancy, Arlington, VA. http://tncweeds.ucdavis.edu/esadocs.html

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By creating larger burn units that use foot trails and two tracks as fire breaksin oak woodlands rather than small burn units that rely on disked fire breaksat the edges of openings, prescribed fire can restore both prairie andadjacent savanna simultaneously.


Common name Scientific name Status Prairie Savanna

Amphibians

Blanchard's cricket frog Acris crepitans blanchardi SC x

Blue-spotted salamander Ambystoma laterale x x

Smallmouth salamander Ambystoma texanum E x x

Eastern tiger salamander Ambystoma tigrinum tigrinum x x

Fowler's toad Bufo fowleri x x

Pickerel frog Rana palustris x

Northern leopard frog Rana pipiens x x

Birds

Cooper's hawk Accipiter cooperii SC x

Northern goshawk Accipiter gentilis SC x

Henslow's sparrow Ammodramus henslowii T x

Grasshopper sparrow Ammodramus savannarum SC x x

Blue-winged teal Anas discors x x

American black duck Anas rubripes x

Short-eared owl Asio flammeus E x x

Upland sandpiper Bartramia longicauda x

American bittern Botaurus lentiginosus SC x

Common nighthawk Chordeiles minor x

Northern harrier Circus cyaneus SC x

Sedge wren Cistothorus platensis x x

Yellow-billed cuckoo Coccyzus americanus x

Northern flicker Colaptes auratus x

Northern bobwhite Colinus virginianus x x

Prairie warbler Dendroica discolor E x x

Kirtland's warbler Dendroica kirtlandii E, LE x

Bobolink Dolichonyx oryzivorus x x

Least flycatcher Empidonax minimus x

Merlin Falco columbarius T x

Northern shrike Lanius excubitor x

Migrant loggerhead shrike Lanius ludovicianus migrans E x

Red-headed woodpecker Melanerpes erythrocephalus x x

Northern mockingbird Mimus polyglottos x

Savanna sparrow Passerculus sandwichensis x x

Eastern towhee Pipilo erythrophthalmus x

Vesper sparrow Pooecetes gramineus x x

Purple martin Progne subis x x

Dickcissel Spiza americana SC x x

Field sparrow Spizella pusilla x x

Eastern meadowlark Sturnella magna x

Western meadowlark Sturnella neglecta SC x x

Appendix A. Wildlife Species of Greatest Conservation Need occurring in prairies and savannas(Eagle et al. 2005). Under �Status�, E is state endangered, LE is federal endangered, T is statethreatened, LT is federal threatened, SC is state special concern, and C is federal candidate species.



Brown thrasher Toxostoma rufum x

Sharp-tailed grouse Tympanuchus phasianellus SC x x

Eastern kingbird Tyrannus tyrannus x x

Barn owl Tyto alba E x

Insects: beetles

American burying beetle Nicrophorus americanus E, LE x

Insects: Butterflies and Moths

Dusted skipper Atrytonopsis hianna T x x

Pipevine swallowtail Battus philenor SC x

Boreal fan moth Brachionycha borealis SC x

Henry's elfin Callophrys henrici SC x

Frosted elfin Callophrys irus T x x

Three-staff underwing Catocala amestris E x x

Quiet underwing Catocala dulciola SC x

Gorgone checkerspot Chlosyne gorgone carlota SC x x

Wild indigo duskywing Erynnis baptisiae SC x x

Persius duskywing Erynnis persius persius T x x

Northern hairstreak Fixsenia favonius ontario SC x

Barrens buckmoth Hemileuca maia SC x

Ottoe skipper Hesperia ottoe T x x

Karner blue Lycaeides melissa samuelis T, LE x x

Doll's merolonche Merolonche dolli SC x

Newman's brocade Meropleon ambifusca SC x

Mitchell's satyr Neonympha mitchellii mitchellii E, LE x

Poweshiek skipperling Oarisma poweshiek T x

Blazing star borer Papaipema beeriana SC x x

Golden borer Papaipema cerina SC x

Maritime sunflower borer Papaipema maritima SC x

Culvers root borer Papaipema sciata SC x

Silphium borer moth Papaipema silphii T x

Regal fern borer Papaipema speciosissima SC x

Tawny crescent Phyciodes batesii SC x

Sprague's pygarctia Pygarctia spraguei SC x x

Grizzled skipper Pyrgus wyandot SC x

Phlox moth Schinia indiana E x x

Leadplant flower moth Schina lucens E x x

Spartina borer moth Spartiniphaga inops SC x

Regal fritillary Speyeria idalia E x x

Appendix A. Continued

Karner blue (Lycaeides melissa samuelis)

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Spotted turtle (Clemmys guttata)



Insects: Cicadas and Hoppers

A leafhopper Dorydiella kansana SC x

A leafhopper Flexamia delongi SC x

Huron River leafhopper Flexamia huroni SC x

A leafhopper Flexamia reflexus SC x

Angular spittlebug Lepyronia angulifera SC x

Great Plains spittlebug Lepyronia gibbosa T x x

A spittlebug Philaenarcys killa SC x x

Red-legged spittlebug Prosapia ignipectus SC x x

Insects: Grasshoppers and Crickets

Secretive locust Appalachia arcana SC x x

Davis's shield-bearer Atlanticus davisi SC x

A spur-throat grasshopper Melanoplus eurycercus x

Blue-legged locust Melanoplus flavidus SC x x

Hebard's green-legged locust Melanoplus viridipes x

Conehead grasshopper Neoconocephalus retusus SC x

Tamarack tree cricket Oecanthus laricis SC x

Delicate meadow katydid Orchelimum delicatum SC x

Barrens locust Orphulella pelidna pelidna SC x x

Atlantic-coast locust Psinidia fenestralis fenestralis SC x

Mammals

Southern red-backed vole Clethrionomys gapperi x

Least shrew Cryptotis parva T x x

Prairie vole Microtus ochrogaster E x

Woodland vole Microtus pinetorum SC x

Least weasel Mustela nivalis x

Indiana bat Myotis sodalis E, LE x x

Deer mouse Peromyscus maniculatus gracilis x

Southern bog lemming Synaptomys cooperi x

Reptiles

Six-lined racerunner Apidoscelis sexlineatus SC x x

Spotted turtle Clemmys guttata T x x

Kirtland's snake Clonophis kirtlandii E x

Blue racer Coluber constrictor foxii x x

Eastern fox snake Elaphe gloydi T x

Black rat snake Elaphe obsoleta obsoleta SC x x

Blanding's turtle Emydoidea blandingii SC x x

Eastern hognose snake Heterodon platirhinos x x

Smooth green snake Liochlorophis vernalis x x

Eastern massasauga Sistrurus catenatus catenatus SC, C x x

Eastern box turtle Terrapene carolina carolina SC x x

Appendix A. Continued


Scientific Name Common Name Sta

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Agalinis gattingeri Gattinger's gerardia E x x

Agalinis skinneriana Skinner's gerardia E x

Agoseris glauca Prairie or Pale agoseris T x

Amorpha canescens Leadplant SC x

Androsace occidentalis Rock-jasmine E x x

Angelica venenosa Hairy angelica SC x

Arabis missouriensis var. Missouri rock-cress SC x x

deamii

Aristida dichotoma Shinner's three-awned X x

grass

Aristida longespica Three-awned grass T x

Aristida tuberculosa Beach three-awned grass T x x

Artemisia ludoviciana Western mugwort T x x

Asclepias hirtella Tall green milkweed T x x

Asclepias ovalifolia Dwarf milkweed E x x

Asclepias purpurascens Purple milkweed SC x x x

Asclepias sullivantii Sullivant's milkweed T x

Aster praealtus Willow aster SC x

Aster sericeus Western silvery aster T x x

Astragalus canadensis Canadian milk-vetch T x

Astragalus neglectus Cooper's milk-vetch SC x

Baptisia lactea Prairie false indigo SC x x

Baptisia leucophaea Cream wild indigo E x

Bartonia paniculata Panicled screw-stem T x

Berula erecta Cut-leaved water-parsnip T x

Besseya bullii Kitten-tails T x

Botrychium pallidum Pale moonwort SC x

Bouteloua curtipendula Side-oats grama grass T x x x

Cacalia plantaginea Prairie indian-plantain SC x x

Calamagrostis stricta Narrow-leaved reedgrass T x

Carex festucacea Fescue sedge SC x

Carex gravida Sedge X x x

Carex richardsonii Richardson's sedge SC x

Celtis tenuifolia Dwarf hackberry SC x

Appendix B. Rare plants associated with prairie and savanna communities. Under �Status,� E is stateendangered, T is state threatened, LT is federal threatened, SC is special concern, and X is state extirpated.

Mic

hael

R. P

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ar, M

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Sullivant�s milkweed(Asclepias sullivantii)

Susa

n R

. Cris

pin,

MN

FI

Leadplant (Amorpha canescens) Bra

dfor

d Sl

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ter,

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Prairie coreopsis(Coreopsis palmata)



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wet

pra

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pra

irie

fen

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lain

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dry

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pin

e b

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Cirsium hillii Hill's thistle SC x x x

Coreopsis palmata Prairie coreopsis T x

Corydalis flavula Yellow fumewort T x x

Cuscuta indecora Dodder SC x

Cuscuta pentagona Dodder SC x

Cypripedium candidum White lady-slipper T x x

Dalea purpurea Purple prairie-clover X x

Dasistoma macrophylla Mullein foxglove T x

Digitaria filiformis Slender finger-grass X x

Dodecatheon meadia Shooting-star E x x

Draba nemorosa Whitlow-grass X ? ? ?

Draba reptans Creeping whitlow-grass T x

Drosera anglica English sundew SC x

Echinacea purpurea Purple coneflower X x x

Eleocharis engelmannii Engelmann's spike-rush SC x

Eleocharis tricostata Three-ribbed spike-rush T x

Eragrostis capillaris Love grass SC x

Eryngium yuccifolium Rattlesnake-master T x x x

Festuca scabrella Rough fescue T x x

Filipendula rubra Queen-of-the-prairie T x

Fimbristylis puberula Chestnut sedge X x

Gentiana flavida White gentian E x x x

Gentiana puberulenta Downy gentian E x

Gentiana saponaria Soapwort gentian X x

Geum triflorum Prairie-smoke T x x

Gillenia trifoliata Bowman's root T x

Gratiola virginiana Round-fruited hedge T ? ? ? ?

hyssop

Helianthus hirsutus Whiskered sunflower SC x x

Helianthus microcephalus Small wood sunflower X ? ? ? ?

Helianthus mollis Downy sunflower T x x

Hieracium paniculatum Panicled hawkweed SC x

Hypericum gentianoides Gentian-leaved St. John's- SC x

wort

Ipomoea pandurata Wild potato-vine T x

Juncus vaseyi Vasey's rush T x x

Appendix B. Continued

Queen-of-the-prairie(Filipendula rubra) Ry

an P

. O�C

onno

r, M

NFI

Prairie smoke(Geum triflorum) M

NFI



tus

wet

pra

irie

lak

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in w

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ie

pra

irie

fen

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bu

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san

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bar

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s

oak

-pin

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ns

pin

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ns

Kuhnia eupatorioides False boneset SC x

Lactuca floridana Woodland lettuce T x

Lechea minor Least pinweed SC x

Lespedeza procumbens Trailing bush-clover X x

Leucospora multifida Conobea SC x

Liatris punctata Dotted blazing-star X x

Linum sulcatum Furrowed flax SC x x

Linum virginianum Virginia flax T x

Lithospermum incisum Narrow-leaved puccoon X x

Ludwigia alternifolia Seedbox SC x x

Lycopodiella margueriteae Northern prostrate T x

clubmoss

Muhlenbergia richardsonis Mat muhly T x

Onosmodium molle Marbleweed X ? ? ? ?

Oryzopsis canadensis Canada rice-grass T x

Oxalis violacea Violet wood-sorrel T ? ? ? ?

Panicum leibergii Leiberg's panic-grass T x x x

Panicum polyanthes Round-seed panic grass E x

Paronychia fastigiata Low-forked chickweed SC x

Penstemon calycosus Smooth beard tongue T x

Penstemon gracilis Slender beard-tongue E x x

Penstemon pallidus Pale beard tongue SC x x

Phaseolus polystachios Wild bean SC x

Phlox bifida Cleft phlox T x

Phlox maculata Spotted phlox T x

Platanthera leucophaea Prairie fringed orchid E,LT x

Polemonium reptans Jacob's ladder T x x

Polygala cruciata Cross-leaved milkwort SC x

Polygala incarnata Pink milkwort X x x x x

Polygonatum biflorum Honey-flowered solomon- X x

var. melleum seal

Polytaenia nuttallii Prairie-parsley X x

Prunus alleghaniensis Alleghany plum SC x x x x

var. davisii

Pycnanthemum pilosum Hairy mountain-mint T ? ? ?

Ranunculus rhomboideus Prairie buttercup T x x


Pink milkwort(Polygala incarnata) Ry

an P

. O�C

onno

r, M

NFI

Prairie buttercup(Ranunculus rhomboideus) Su

san

R. C

rispi

n, M

NFI



tus

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pin

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Rhynchospora Tall beak-rush SC x

macrostachya

Rudbeckia subtomentosa Sweet coneflower X ? ? ? ? ?

Ruellia humilis Hairy ruellia T x x x

Sanguisorba canadensis Canadian burnet T x x

Scirpus clintonii Clinton's bulrush SC x

Scleria pauciflora Few-flowered nut-rush E x x x

Scleria triglomerata Tall nut-rush SC x x x x x

Scutellaria incana Downy skullcap X x

Scutellaria parvula Small skullcap T x

Silene stellata Starry campion T x

Silene virginica Fire pink T x

Silphium integrifolium Rosinweed T x

Silphium laciniatum Compass-plant T x

Sisyrinchium atlanticum Atlantic blue-eyed-grass T x

Sisyrinchium farwellii Farwell's blue-eyed-grass X ? ? ? ? ? ?

Sisyrinchium strictum Blue-eyed-grass SC x

Solidago bicolor White goldenrod SC x

Solidago missouriensis Missouri goldenrod T x

Spiranthes ochroleuca Yellow ladies'-tresses SC x x

Spiranthes ovalis Lesser ladies'-tresses T x

Sporobolus clandestinus Dropseed SC x

Sporobolus heterolepis Prairie dropseed SC x x

Strophostyles helvula Trailing wild bean SC x

Tomanthera auriculata Eared false foxglove X x

Tradescantia bracteata Long-bracted spiderwort X x

Tradescantia virginiana Virginia spiderwort SC x x

Trichostema brachiatum False pennyroyal T x

Trichostema dichotomum Bastard pennyroyal T x x

Triplasis purpurea Sand grass SC x x

Vaccinium cespitosum Dwarf bilberry T x

Valeriana edulis var. Edible valerian T x

Viola novae-angliae New England violet T x

Viola pedatifida Prairie birdfoot violet T x

Zizia aptera Prairie golden alexanders T x


Compass-plant(Silphium laciniatum) B

radf

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ghte

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NFI

Fire pink (Silene virginica)

MN

FI

Virginia spiderwort (Tradescantia virginiana)

Bra

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Prairie Community Descriptions

Wet Prairie

General DescriptionWet prairie is a lowland grassland of southern LowerMichigan found on saturated, level, seasonallyinundated sites. It often occurs along the margins oflakes, streams, and rivers. Almost exclusivelyoccurring on glacial outwash landforms, wet prairiesare usually found near the base of moraines. Soils aregenerally loam with a neutral pH (average 6.9). Waterlevels may vary both seasonally as well as from year toyear, with several inches of water or more generallyoccurring in the spring.

Ecological ProcessesWhile fires were important historically, a seasonallyhigh, fluctuating water level is the primary process thathelps keep wet prairies mostly free of woody plants inpresent day.

Characteristic PlantsWet prairies are dominated by plants such as blue-jointgrass (Calamagrostis canadensis), prairie cord grass(Spartina pectinata), twig-rush (Cladiummariscoides), and various sedges (Carex bebbii, C.stricta, etc.).

Threats and ConservationThe primary threats to wet prairies include draining orfilling of wetlands, altered hydrology of lake levels andrivers by dams or other structures, and invasive speciessuch as giant reed (Phragmites australis), cat-tail(Typha spp.) reed canary grass (Phalarisarundinacea). Land managers seeking to restore wetprairies should focus on hydrology and maintaining orrestoring seasonally high, fluctuating water levels.Fire management and control of invasive plants arealso important priorities.

Similar CommunitiesCommunities similar to wet prairie include lakeplainwet prairie, wet-mesic prairie, and prairie fen.Lakeplain wet prairies can be easily separated as theyonly occur on glacial lakeplain. Wet-mesic prairiesgenerally have a slightly lower water table and areoften dry to the feet except in the wettest times of year.They correspondingly have more upland species,particularly of prairie grasses such as big bluestem(Andropogon gerardii), Indian grass (Sorghastrumnutans), and showy wildflowers such as gray-headedconeflower (Ratibida pinnata) and prairie dock

APPENDIX C: NATURAL COMMUNITY DESCRIPTIONS

(Silphium terebinthinaceum). Wet-mesic prairies areclosely associated with wet prairies and historicallycould often be found directly adjacent, separated by asmall topographical rise. Prairie fens may havesimilar vegetation as wet or wet-mesic prairies buthave organic (muck or peat) soils rather than mineral(sand, silt, and clay) soils.

Lakeplain Wet Prairie

General DescriptionLakeplain wet prairie is similar to wet prairie in that itis found on low, saturated, seasonally inundated sites.However, they are exclusively found on the glaciallakeplain of the Great Lakes and in Michigan arelimited to the regions of Saginaw Bay, the St. ClairDelta, and the western margin of Lake Erie. Therethey are usually found on sandy soil (but also occur onfine sandy loam, loam, and silty clay loam) with a highpH (8.0).

Ecological ProcessesLike wet prairies, hydrology was one of the keyprocesses that helped keep sites relatively free of treesand shrubs. Standing water is typical during thespring, and some slight depressions may remain wetyear-round. In addition to a water table that fluctuatesseasonally with precipitation, hydrology is also closelytied the Great Lakes water level, which is known tofluctuate by as much as 2 meters (approximately 6feet) over a cycle of 15-20 years. As water levelsfluctuated, the wet prairie community migrated inlandor lakeward across the landscape. Fire was also animportant process that maintained graminoiddominance historically.

Susa

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Wet prairies are dominated by blue-joint grass and prairiecordgrass, along with less common forbs like gray-headed coneflower (Ratibida pinnata).


Characteristic PlantsPlants of lakeplain wet prairies are similar to otherlowland prairie communities and include blue-jointgrass, prairie cordgrass, Baltic rush (Juncus balticus),twig-rush, shrubby cinquefoil (Potentilla fruticosa),swamp milkweed (Asclepias incarnata), and sedges(Carex stricta, C. aquatilis, C. lanuginosa).

Threats and ConservationIn the past, the primary threats to lakeplain wet prairieshave been draining, tiling, and conversion toagriculture. Development, particularly along thelakeshore has also severely reduced the extent of thiscommunity. Managers wishing to maintain and restorelakeplain prairies face a difficult task, since thepresence of roads, residential and industrialdevelopment, and agricultural fields restrict the naturalmovement of prairie across the landscape as GreatLakes water levels fluctuate. To conserve prairies onthe lakeplain most effectively, large sites thatextend inland should be identified that allowfor gradual shifting of water levels. Whereformer agricultural fields are present,restoring hydrology by the filing of ditchesand breaking of drain tiles may be necessary.Controlling highly aggressive invasive speciessuch as giant reed and narrow-leaved cattail(Typha angustifolia) is also a priority.

Similar CommunitiesSimilar communities to lakeplain wet prairieinclude wet prairie, lakeplain wet-mesicprairie, southern wet meadow, emergentmarsh, and Great Lakes marsh. As describedabove, wet prairies are closely related but arenot found on glacial lakeplains. Lakeplainwet-mesic prairies are often found directly

adjacent to lakeplain wet prairies but occur on slightlyhigher ground and with a greater component of uplandspecies such as big bluestem, Indian grass, switchgrass (Panicum virgatum), Ohio goldenrod (Solidagoohioensis), and mountain-mint (Pycnanthemumvirginianum). Southern wet meadow is more typicallyfound on organic (peat or muck) soils and is usuallydominated by sedges (Carex stricta, C. lacustris).Emergent marsh typically occurs in permanent (thoughshallow) water and is dominated by sedges (Carex,Eleocharis) and bulrushes (Scirpus) as well as aquaticplants with floating leaves. Great Lakes marsh is acomplex community, of which some regions and zonesare similar to emergent marsh but located on themargins of the Great Lakes. Where they occurredadjacent to lakeplain prairies, they often formed part ofthe shifting mosaic in response to fluctuating lakelevels. For a more detailed overview of lakeplain wetprairies, please see the abstract available on the MNFIwebsite (Albert and Kost 1998a).

Prairie Fen

General DescriptionPrairie fen is a wetland found on organic (muck orpeat) soils dominated by herbaceous vegetationcharacteristic of both prairies (such as grasses like bigbluestem) and fens (various sedges). As a peatland, ittechnically is not classified as a true prairiecommunity, which are always found on mineral soils.However, it is included here because of its similarvegetation and importance to conservation ofbiodiversity. Prairie fens occur in outwash plains andare often located adjacent to moraine or ice-contactridges, where coarse-textured soil and steeptopography result in a constant supply of calcareous

Gar

y R

eece

, MN

FI

Standing water is often present in lakeplain wet prairies,especially during spring or when Great Lakes water levelsare high.

Prairie fens are characterized by a mixture of fen vegetation like tamaracksand shrubby cinquefoil and prairie grasses like big bluestem.

Mic

hael

A. K

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groundwater (rich in calcium and magnesiumbicarbonates) flowing out of the base of hills next tolakes and small headwater streams. The organic soilshave a very high pH (8.0), often with a concentrationof bicarbonates so high that they precipitate out of thewater in the form of marl.

Ecological ProcessesHydrology is of utmost importance in fens. Theconstant supply of groundwater keeps the organic soilssaturated year-round, and also helps maintain anherbaceous-dominated plant community. Numerousnative and non-native shrubs can tolerate saturatedsoils, however, and periodic fires were critical tomaintaining open conditions.

Characteristic PlantsFens are very complex wetland systems, with at leastthree vegetation zones that often grade from one toanother based on hydrology and fire frequency. Low-lying, inundated flats are often dominated by bulrush(Scirpus acutus), twig-rush, and spike-rushes(Eleocharis spp.). Fen meadows are the mostdiagnostic and diverse zone, and is dominated byindicator species such as shrubby cinquefoil, sedges(Carex stricta, C. aquatilis, C. sterilis, C. flava, C.tetanica, C. buxbaumii), big bluestem, Indian grass,mountain-mint, grass-of-Parnassus (Parnassiaglauca), and goldenrods (Solidago ohioensis, S.riddellii). The third zone is dominated by woodyspecies such as tamarack (Larix laricina), poisonsumac (Toxicodendron vernix), and bog birch (Betulapumila). These woody species can also be foundscattered throughout the other zones as well. Ingeneral, any open wetland in southern Michigan withsaturated organic soils and a combination of tamarack,shrubby cinquefoil, prairie grasses and fine-leavedsedges is most likely a prairie fen.

Threats and ConservationPrairie fens are among the most biologically diversenatural communities in Michigan, and theirconservation priority is among the highest of allwetland systems. Because hydrology and the constantflow of groundwater is so critical to their functioning,protecting fens from ditching, draining, and filling iscrucial. In the past, marl mining and the creation ofponds severely altered these systems. More recently,disruption of groundwater flows from aquifer use bylarge-scale development is suspected of causinghydrologic changes. The cessation of natural fires hasalso led to broad scale changes as woody shrubs andtrees filled in and shaded out the herbaceousvegetation. Exotic plants such as glossy buckthorn

have also become established, especially in areas ofaltered hydrology. Because of their high leaf surfacearea (compared to native herbaceous plants) andability to transpire large amounts of water, glossybuckthorn is also suspected of lowering the water tablein areas of severe infestations, further disruptinghydrology. Managers seeking to restore prairie fensshould 1) maintain hydrology (or restore if necessary),2) carefully but aggressively control exotic speciessuch as glossy buckthorn, 3) remove overly densenative trees and shrubs that are shading out remnantfen, and 4) consider prescribed burning to controlshrubs and stimulate native herbaceous plants.

Similar CommunitiesSimilar communities to prairie fen include wet-mesicprairie, wet prairie, southern wet meadow, shrub-carr,and relict conifer (tamarack) swamp. Wet-mesic andwet prairies may be very similar in vegetativecomposition but like all true prairie communities theyhave mineral soils rather than organic soils, acharacteristic easily noted by a change in the firmnessof the soil surface when walking up from a fen to adrier mineral soil prairie. Southern wet meadow is awetland community with organic soil but is usuallydominated by tall sedges (Carex stricta, C. lacustris)and cattails. Shrub-carr is a successional wetlandcommunity dominated by dense shrubs such asdogwood (Cornus spp.), willow (Salix spp.), as well asshrubs characteristic of fens. Relict conifer swamp is aforested wetland community dominated by tamarack,and historically was often found adjacent to prairiefens. For a more detailed overview of prairie fens,please see the abstract available on the MNFI website(Spiels et al. 1999).

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Prairie fens often occur at the margins of lakes or streamsadjacent to oak-dominated uplands.


Wet-mesic Prairie

General DescriptionWet-mesic prairie is a lowland grassland ofsouthern Lower Michigan found on moist,level, occasionally inundated sites. It oftenoccurs along the margins of lakes, streams,rivers, and sometimes wet marshes. Almostexclusively occurring on glacial outwashlandforms, wet-mesic prairies are often foundnear the base of moraines. Soils are generallyloam with a neutral pH (average 6.9) and aremoist but rarely saturated, a characteristiceasily noted by a change in the firmness of thesoil surface when walking up from a wettercommunity, especially from prairie fens or wetmeadows with saturated organic (muck) soils.The water table is generally below the surface,but can vary both seasonally as well as from year toyear.

Ecological ProcessesLike wet prairie, hydrology and the correspondingseasonally high water table is an important ecologicalprocess. However, because standing water is rarelypresent, it is less of a factor in restricting the growth oftrees and shrubs. Fire plays a much more significantrole in maintaining the herbaceous community andkeeping back woody species.

Characteristic PlantsWet-mesic prairies are often dominated by grassessuch as big bluestem, Indian grass, and prairie cordgrass. Wetland sedges (Carex stricta, C. bebbii) arealso common. Characteristic wildflowers includethimbleweed (Anemone virginiana), gray-headedconeflower, prairie dock, tall meadow-rue (Thalictrumdasycarpum) and Culver�s root (Veronicastrumvirginicum).

Threats and ConservationLike many communities, wet-mesic prairies arethreatened by conversion to agriculture anddevelopment. Remnant sites are often highlythreatened by invasive shrubs such as autumn-olive,buckthorn, and honeysuckle, all of which growexceedingly well in the moist soil that characterizes thecommunity. Native shrubs such as dogwood (Cornusspp.) can also form large thickets that shade out prairievegetation. Succession is also a major concern,especially in sites that are not managed with prescribedfire. Because most shrubs sprout vigorously if top-killed by fire or cutting, managers may also want toconsider selective use of herbicides on unwanted

woody vegetation. If altered, restoring hydrology isalso an important step to restoring and conserving wet-mesic prairies.

Similar CommunitiesCommunities similar to wet-mesic prairie includelakeplain wet-mesic prairie, wet prairie, mesic prairie,and prairie fen. Lakeplain wet-mesic prairies can beeasily separated as they only occur on glaciallakeplains. Wet prairies generally have a slightlyhigher water table and often have standing water in thespring. Mesic prairies are drier and have a higherproportion of drier-site species such as sky-blue aster(Aster oolentangiensis), prairie coreopsis (Coreopsispalmata), and bush-clovers (Lespedeza capitata, L.hirta). Prairie fens may have nearly identicalvegetation as wet-mesic prairies but have organic(muck or peat) soils rather than mineral (sand, silt, andclay) soils.

Firm, mineral soil underfoot is one of the factors distinguishing wet-mesicprairies from prairie fens, which always occur on organic, peat-based soils.

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Ryan

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Prairie cordgrass (Spartina pectinata)


Lakeplain Wet-mesic Prairie

General DescriptionLakeplain wet-mesic prairie is similar to lakeplain wetprairie in that it is found on low, saturated,occasionally inundated sites on glacial lakeplains ofthe Great Lakes. In addition to the regions of SaginawBay, the St. Clair Delta, and the western margin ofLake Erie, they are also occasionally found inland ofthe west coast of Michigan in Allegan and Berriencounties. Soils generally have a high pH (8.0), usuallywith a texture of fine sandy loam which is oftenunderlain by clay (1-3 meters below the surface).

Ecological ProcessesIn lakeplain prairies hydrology is one of the keyprocesses that help keep sites relatively free of treesand shrubs. Soils are generally moist but typicallysites are not inundated except in the spring and orduring the wettest years. However, with typicallysandy soils at the surface and clay deposits beneath,the seasonally fluctuating water level often leads tospring flooding followed by growing season drought.This combination serves to favor specially adaptedplants such as grasses and forbs with deep roots thatare also tolerant of flooding. In addition to seasonallyfluctuation water tables, the hydrology of lakeplainwet-mesic prairies is also closely tied the Great Lakeswater level, which is known to fluctuate by as much as2 meters (approximately 6 feet) over a cycle of 15-20years. As water levels fluctuated, the prairiecommunity migrated inland or lakeward across thelandscape. Fire was also an important process thatmaintained graminoid dominance historically, and mayhave played a larger role in keeping sites open in wet-mesic prairies than wetter prairie communities.

Characteristic PlantsLakeplain wet-mesic are often dominated by bigbluestem, little bluestem (Andropogon scoparium)Indian grass, switch grass, and sedge (Carexlanuginosa). Characteristic wildflowers include paleIndian-plantain (Cacalia plantaginea), shrubby St.John�s-wort (Hypericum kalmianum), shrubbycinquefoil, white lady�s-slipper (Cypripediumcandidum), and goldenrods (Solidago nemoralis, S.ohioensis).

Threats and ConservationIn the past, many lakeplain prairies have been lost todraining, tiling, and conversion to agriculture.Industrial and residential development has alsoseverely reduced the extent of this community,especially in southeast Michigan. Managers wishing

to maintain and restore lakeplain prairies face adifficult task, since the presence of ditches andagricultural drain tiles have lowered the water anddisrupted the hydrology. Additionally, roads,residential and industrial development, andagricultural fields restrict the natural movement ofprairie across the landscape as Great Lakes waterlevels fluctuate. To conserve prairies on the lakeplainmost effectively, large sites that extend inland shouldbe identified that allow for gradual shifting of waterlevels. Where possible, conservation agreements onagricultural land adjacent to prairie remnants shouldbe sought. Restoring hydrology by filing ditches andbreaking drain tiles may also be necessary.Controlling invasive species is also a priority. Nativeshrubs such as dogwood (Cornus spp.) can also formlarge thickets that shade out prairie vegetation andsuccession is also a major concern. Land managersshould carefully consider the use of prescribed fire tomaintain an open landscape.

Similar CommunitiesSimilar communities to lakeplain wet-mesic prairieinclude lakeplain wet prairie, mesic sand prairie, andwet-mesic prairie. Lakeplain wet prairies generallyoccur at a slightly slower elevation and can havestanding water throughout much of the growingseason. Additionally, they tend to be dominated byplants more tolerant of a high water table such as blue-joint grass, rushes (Juncus spp.), and tussock sedges(Carex stricta, C. aquatilis). Mesic sand prairies tendto occur on slightly higher ancient beach ridges and aremore prone to drought. Additionally, the soil (usuallysand to sandy loam) tends to be a strongly acid (pH5.5). Wet-mesic prairies are similar to lakeplain wet-mesic prairies but exclusively occur on glacial outwashand never on the glacial lakeplain. For a more detailedoverview of lakeplain wet-mesic prairies, please seethe abstract available on the MNFI website (Albert andKost 1998b).

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nis A

. Alb

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MN

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Prairie cordgrass and Ohio goldenrod are commonon the flat expanses of lakepain wet-mesic prairies.


Northern Wet-mesic Prairie

General DescriptionNorthern wet-mesic prairie is a variation of mesic sandprairie occurring in northern Michigan. Primarilyoccurring on moist, level, occasionally inundated sites,they are most often found in seasonal drainages withinoutwash depressions, often surrounded by jack pine(Pinus banksiana). Soils are generally sand or sandyloam with a slightly acid to circumneutral pH (5.8 to7.0) and are moist but rarely saturated. The watertable is generally below the surface, but can vary bothseasonally as well as from year to year. Thiscommunity type is currently under evaluation by MNFIecologists and may eventually be lumped into abroader definition of mesic sand prairie (M. Kost, pers.communication).

Ecological ProcessesA seasonally high water table and fire play a importantroles in maintaining the herbaceous community andkeeping back woody species. Due to more northerlylatitude and the tendency for the community to occurin open low-lying topographic areas, growing seasonfrosts may also help discourage trees and shrubs.

Characteristic PlantsCharacteristic plants include prairie species fromsouthern latitudes such as big bluestem as well asplants of wetlands like bluejoint grass, rushes (Juncusbalticus), and sedges (Carex lacustris, Dulichiumarundinaceum). Due to their tendency to occur oninfertile, sandy soils, jack pine is also common in oradjacent to the prairie.

Threats and ConservationThe primary threat to most sites is damagefrom illegal ORV activity. Lack of fire mayalso lead to a greater dominance by woodyspecies over time.

Similar CommunitiesSimilar communities include wet-mesicprairie, lakeplain wet-mesic prairie, mesicsand prairie, and northern wet meadow. Allbut northern wet meadow are found only insouthern lower Michigan. Of these,lakeplain mesic sand prairie may mostclosely resemble northern wet-mesic prairiein species composition, but they tend tohave highly acidic soils and are limited toold lake beds of the Great Lakes. Northernwet meadows occur along the margins ofstreams and are dominated by sedges

(Carex stricta, etc.) and bluejoint grass. Moreimportantly, they have organic (muck) soils rather thanthe mineral soils of prairies.

Mesic Sand Prairie

General DescriptionMesic sand prairies occur on sandy glacial lakeplainsand outwash plains with a seasonally high, fluctuatingwater table. Soils are sandy, usually acidic (averagepH 5.5), and are prone to drought during the drysummer months, but during a wet spring may be nearlyinundated. Consequently, plant species of both wetand dry prairies are found growing together.

Ecological ProcessesSeasonally high water levels in spring and sandy,infertile, drought-prone soils in the summer combineto limit growth of trees and shrubs. Fires were alsoimportant historically, since these usually smallprairies occurred in a larger matrix of fire-dominatedoak savanna. Topography is also a key factor in mesicsand prairies, since the smallest changes in elevation (afoot or less) may lead to a gradation towards drier ormore wet-mesic conditions.

Characteristic PlantsMost notable about the vegetation is the prevalence ofdry prairie species such as big bluestem, littlebluestem, poverty grass (Danthonia spicata), fieldmilkwort (Polygala sanguinea), and arrow-leavedviolet (Viola sagittata) growing next to species adaptedto wetter conditions like mountain-mint, colic-root(Aletris farinosa), meadow-sweet (Spiraea spp.), andeven tall nut-rush (Sceleria triglomerata) and spike-rushes (Eleocharis spp.).

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Mesic sand prairies are characterized by acidic sandy soil that is seasonallywet but prone to drought in the summer.


Threats and ConservationThreats to mesic sand prairie include a lack of fire andpotential succession to trees and shrubs. Most of thecurrently known sites also occur in rapidlysuburbanizing areas of southeast Michigan, wheredevelopment is a looming threat. Planners shouldwork with land managers to ensure fully functioningsystems (the mesic prairies as well as the wetlands andupland forest that surround them) are conserved. Dueto the importance of hydrology, any ditching or fillingnot only in but also adjacent to the prairies should beprevented. Finally, managers should seek to carefullyrestore fire to the landscape, being especially cognizantof political and social issues where sites are in closeproximity to suburban areas.

Similar CommunitiesSimilar communities include mesic prairie, dry sandprairie, northern wet-mesic prairie, and coastal plainmarsh. Mesic prairies are easily distinguished by theirblack, loamy soils. While dry sand prairies havesimilar droughty, sandy soils, they lack the presence ofa fluctuating water table and thushave no plants adapted to wetter siteconditions. Northern wet-mesicprairies can have similar soils aswell as similar plants, but are foundonly northern Michigan, whilemesic sand prairies are mostly foundin southern Michigan. One of theclosest natural communities may becoastal plain marsh, which oftencontains a small band of mesic sandprairie on upland edges. Themarshes are often wet, and even ifno standing water is present, theyshould be distinguishable by thepresence of peat mixed with sand

and a dominance by coastal plain species such asbluejoint grass, nut-rush (Cladium mariscoides),hyssop hedge-nettle (Stachys hyssopifolia), grass-leaved goldenrod (Euthamia remota), and black-fruited spike rush (Eleocharis melanocarpa).

Mesic Prairie

General DescriptionMesic prairie, also called tall grass or black soilprairie, is a native grassland community dominated bybig bluestem, little bluestem, and Indian grass.Typically, mesic prairie occurred on slightly acid (pH6.2) loam or sandy loam soils in level, moderatelywell-drained outwash plains. Mesic prairies werelimited to the southwest corner of the state whereTranseau�s Prairie Peninsula barely extended intoMichigan (1935). Although mesic prairie was nevercommon in the state, it did comprise several large,historical sites of note, some of which were even usedto identify early settlements and local governmentunits, such as Prairie Rhonde, a 12,000 acre formermesic prairie in Kalamazoo County.

Ecological ProcessesBecause they fell in the middle of the moisturecontinuum, neither being too wet nor too dry, the onlyecological process that maintained an open conditionwas frequent fire. Following the cessation of fires,mesic prairies quickly converted to savanna and thento forest, or were converted to agriculture. Today thetiny remnants that remain almost always occur alongrailroad tracks, where they were kept open by firessparked by passing trains. Animal disturbances suchas buffalo grazing and wallows were historicallyimportant small-scale disturbances that helpedmaintain high species diversity. Today, mound-building ant colonies are also an important small-scale

disturbance agent that help mix and aerate thesoil, as well as provide microtopography andseed beds when abandoned. Dense clusters ofant mounds (often reaching several feet inheight) can serve as an easily identifiableindicator of unplowed ground (at least withinseveral decades) potentially capable ofsupporting prairie.

Characteristic PlantsMesic prairies are primarily dominated by bigbluestem, but other prairie grasses such asIndian grass, little bluestem, and prairie cordgrass can also be frequently found. Othercharacteristic herbaceous plants include sedges(Carex bicknellii), prairie coreopsis (Coreopsis

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Tall nut-rush (Sceleria triglomerata)

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Prairie coreopsis(Coreopsis palmata)


palmata), wild yam (Dioscorea villosa), pale-leavedsunflower (Helianthus strumosus), false boneset(Kuhnia eupatorioides), prairie dock, yellowpimpernel (Taenidia integerrima), hoary vervain(Verbena stricta), American vetch (Vicia americana),and golden alexanders (Zizia aurea).

Threats and ConservationWith virtually all mesic prairies lost or degraded byconversion to agriculture or succession, efforts shouldbe to identify, manage, and expand remnants. Inparticular, where remnants exist adjacent to railroadtracks, managers should seek opportunities to expandprairie vegetation through prescribed burning and/orplanting. If planting, carefully consider what methodto use as some techniques may produce dense standsof grasses with little ecological resemblance to a true,diverse prairie. In addition, if planting in closeproximity to an existing remnant, the use of localgenotype seed (from the remnant itself and/or othernearby remnants if at all possible) is stronglyrecommended, even at the expense of longerrestoration time, fewer acres planted, and possiblycost. Frequent fire (every 1-3 years) is also absolutelycritical to maintaining prairie vegetation. Lack of fireor less frequent burns will result in gradual successionto woody species.

Similar CommunitiesCommunities similar to mesic prairie include wet-mesic prairie, mesic sand prairie, woodland prairie,bur oak plains, and oak openings. Wet-mesic prairieoften has a water table at or near the surface in springwith correspondingly more wet-site species such asmountain-mint, wetland sedges (Carex stricta, C.bebbii), and tall meadow-rue. Mesic sand prairie hassoils that are predominantly acidic (pH 5.0) sands, andis characterized by a seasonally fluctuating water tablewith a mix of wetland species such as meadow sweet(Spiraea spp.) with dry upland species like littlebluestem. Woodland prairie is a dry-mesic prairie typewith a higher proportion of dry-site indicators such asPennsylvania sedge (Carex pensylvanica), butterflyweed (Asclepias tuberosa), western sunflower(Helianthus occidentalis) and hairy aster (Asterpilosus). Bur oak plains is a state-extirpated mesicsavanna community. It is thought to have had a 10-40% canopy cover of bur oak and herbaceousvegetation similar to mesic prairie. Oak openings is adry-mesic savanna community, now exceedingly rare,with a mixed oak canopy cover also historicallyranging from 10-40%. For a more detailed overviewof mesic prairie, please see the abstract available onthe MNFI website (Kost 2004a).

Woodland Prairie

General DescriptionWoodland prairie is a dry-mesic grassland dominatedbig bluestem, Indian grass, and little bluestem. It isfound on well-drained level outwash plains and coarse-texture end moraines. Soils are generally sandy loamand pH is moderately acid, ranging from 5.2 to 6.7.Historically, woodland prairie occurred in relativelytreeless pockets within oak openings, a dry-mesicsavanna community that occupied much of thesavanna-prairie complex in southern Michigan.

Ecological ProcessesFire was the predominant ecological process thatmaintained an open condition within woodlandprairies, with prairie gradually converting to oakopenings as fire frequency decreased. With well-drained, relatively sandy soils, seasonal drought alsolikely played a role in limiting the growth of trees andmaintaining an open condition. Animal disturbancessuch as buffalo grazing and wallows were historicallyimportant small-scale disturbances that helpedmaintain high species diversity. Today, mound-building ant colonies are also an important small-scaledisturbance agent that help mix and aerate the soil, aswell as provide microtopography and seed beds whenabandoned. Dense clusters of ant mounds (oftenreaching several feet in height) can serve as an easilyidentifiable indicator of unplowed ground (at leastwithin several decades) potentially capable ofsupporting prairie.

Historically, woodland prairies occurred in close proximity to oakopenings, a dry-mesic savanna community.


VegetationWoodland prairies are dominated by native grassessuch as big bluestem, little bluestem, and Indian grass.Pennsylvania sedge is also often found, along withcharacteristic wildflowers such as hairy aster (Asterpilosus), thimbleweed (Anemone cylindrica), westernsunflower (Helianthus occidentalis), stiff goldenrod(Solidago rigida), butterfly weed (Asclepias tuberosa),and leadplant (Amorpha canescens).

Threats & ConservationThose woodland prairies that weren�t converted toagriculture quickly grew up into closed canopy oakforest following the cessation of frequent fires.Livestock grazing also impacted virtually all sites,resulting in many direct and indirect changes, one ofwhich is the current prevalence of bluegrass at manysites. Today, only tiny remnants of woodland prairieremain, almost always occurring along railroad trackswhere they were kept open by fires sparked by passingtrains. Where remnants do still exist, managers shouldseek opportunities to expand prairie vegetation throughprescribed burning and/or planting. If planting,carefully consider what method to use as sometechniques may produce dense stands of grasses withlittle ecological resemblance to a true, diverse prairie.In addition, if planting in close proximity to anexisting remnant, the use of local genotype seed (fromthe remnant itself and/or other nearby remnants if at allpossible) is strongly recommended, even at theexpense of longer restoration time, fewer acresplanted, and possibly cost. Frequent fire (every 1-3years) is also absolutely critical to maintaining prairievegetation. Lack of fire or less frequent burns willresult in gradual succession to woody species.

Similar CommunitiesSimilar communities to woodland prairie includemesic prairie, mesic sand prairie, hillside prairie, drysand prairie, and oak openings. Mesic prairie occurredon slightly better soil conditions (loam with an averagepH of 6.2) with characteristic plants such as rosinweed(Silphium integrifolium), yellow pimpernel, prairiecoreopsis, and golden alexanders. Mesic sand prairiehas sandy soils similar to woodland prairie but they areoften strongly acid (pH 5.5) with a seasonallyfluctuating water table that facilitates growth of bothwetland species such as meadowsweet and dry-sitespecies like Pennsylvania sedge and little bluestemLike woodland prairie, hillside prairie is also largely adry-mesic community but is found on open, steephillsides and bluffs, often above large rivers or smallkettle lakes. Characteristic plants include Americanbellflower (Campanula rotundifolia), needle grass

(Stipa spartea), and the rare kitten-tails (Besseyabullii). Dry sand prairie is the driest prairiecommunity found in Michigan and is often dominatedby Pennsylvania sedge rather than tall prairie grasses.Oak openings is a dry-mesic savanna community witha 5-80% canopy of white and black oaks. Historically,oak openings graded into woodland prairie in ashifting mosaic determined by fire frequency. For amore detailed overview of woodland prairie, please seethe abstract available on the MNFI website (Kost2004b).

Hillside Prairie

General DescriptionHillside prairie is a dry-mesic grassland occurring onsteep, open slopes, often on south or west-facinghillsides above large rivers and kettle lakes. Soilsrange from sandy loam to loamy sand and range fromstrongly acid (pH 5.3) to circumneutral (6.8).Historically, hillside prairies often had a thin canopy ofblack and white oak more similar to savanna, inpresent day they may appear to have an almostcompletely closed canopy. Various types of oaksavanna and dry-mesic oak forest commonlysurrounded hillside prairies on adjacent, less steepterrain and slopes with more northern or easternaspects.

Ecological ProcessesFire was important in promoting herbaceousvegetation and keeping back woody species, but terrainand landscape position played a uniquely critical rolein maintaining an open condition on hillside prairies.Steep south and west facing slopes receive a muchhigher degree of direct sunlight, making them drierand more drought-prone than comparable north andeastern aspects. In addition, open hillsides areconstantly exposed to drying winds, further reducingmoisture availability.

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Butterfly weed (Asclepias tuberosa)


VegetationA thin canopy of white and black oak is commonlypresent, along with other woody species such as pignuthickory, black cherry (Prunus serotina), and floweringdogwood (Cornus florida). Eastern redcedar(Juniperus virginiana) is also an excellent indicatorspecies found on almost all relict hillside prairies,though the prevalence of this fire-sensitive species inpresent day is likely due mainly to fire suppression.Numerous characteristic herbaceous species can alsobe found, including little bluestem, needle grass, bigbluestem, American bellflower, and the rare plantskitten-tails, side-oats (Bouteloua curtipendula), andprairie golden-alexanders (Zizia aptera).

Threats & ConservationToo steep to farm or graze, hillside prairies slowlyfilled in with woody species with decreasing firefrequency. More recently, exclusive residentialdevelopments on scenic river bluffs and hillsidesoverlooking small inland lakes have resulted in thenear complete loss of this community. Several rareplant species endemic to hillside prairies in Michigansuch as kitten-tails have declined to such a great extentthat their survival in the state is in serious question.

Managers wishing to restore hillside prairies shouldseek out remnant sites and apply prescribed fire iffeasible. Due to their unique terrain, many sitesfacilitate easy use of controlled fire with a naturalfirebreak in the form a river or lake below and a levelarea above, at which another firebreak can be created.Thinning of the woody canopy may also be required,and control of invasive species like autumn-olive,honeysuckle, and buckthorn will likely be necessary.Care should be taken to avoid eroding soil on the steepsandy slopes when conducting any management,survey, or monitoring.

Similar CommunitiesCommunities similar to hillside prairie includewoodland prairie, oak barrens, oak openings, and dry-mesic southern forest. Like hillside prairie, woodlandprairie is also largely a dry-mesic community but isfound on mostly level, sandy ground rather than onopen, steep hillsides and bluffs. Oak barrens is a drysavanna community and is often dominated byPennsylvania sedge and scattered black oak. It may befound on excessively dry, flat plains above slopes inclose association with hillside prairie. Morecommonly, dry-mesic conditions predominate, makingoak openings a historically common savanna foundadjacent to hillside prairie. Where fire frequency islower due to slope, aspect, or human intervention,more closed-canopy dry-mesic southern forest mayprevail instead of the open-canopy savanna of oakopenings.

Dry Sand Prairie

General DescriptionDry sand prairie is a dry grassland community withshort, sparse, vegetation dominated by Pennsylvaniasedge with lesser amounts of big and little bluestem.Primarily found on level to rolling outwash plains,soils are well drained to excessively well drainedacidic (pH 4.6 � 5.7) loamy sands. Dry sand prairie islocated primarily in northern Lower Michigan and isfound in close association with oak barrens and oak-pine barrens in the Newaygo Outwash as well asfurther north where it occupies small patches withinthe pine in the High Plains Subsection north and eastof Grayling.

Ecological ProcessesWhile periodic fire was important in promoting theherbaceous plant community, droughty soils alsohelped maintain an open condition by limiting treeestablishment and growth. In addition, growingseason frosts also inhibit growth and establishment of

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Hillside prairies occur on steep south or west-facingslopes above large rivers or kettle lakes.


woody vegetation in the pine barrens,particularly in low depressionsknown as frost pockets.

Characteristic PlantsVegetation is often low, short, andsparse, with Pennsylvania sedgeoften dominating and big bluestemand little bluestem sometimesoccurring as co-dominants. Othercommon grasses include povertygrass (Danthonia spicata), hair grass(Deschampsia flexuosa), June grass(Koeleria macrantha), and rice grass(Oryzopsis asperifolia, O. pungens).Low shrubs are also common, suchas sweet-fern (Comptoniaperegrina), sand cherry (Prunuspumila), blueberry (Vacciniumangustifolium), dewberry (Rubusflagellaris), and bearberry (Arctostaphylos uva-ursi).Wildflowers are typically sparse compared to otherprairie systems, but characteristically include roughblazing star (Liatris aspera), harebell (Campanularotundifolia), butterfly weed, blue toadflax (Linariacanadensis), wild lupine (Lupinus perennis), andhorsemint (Monarda punctata).

Threats and ConservationThough their open character resulted in many areasbeing plowed, most dry sand prairies were too dry,sandy, and acidic to be productive agriculturally.Many areas originally held by private landownersreverted back to public ownership when they could notbe farmed. The cessation of periodicwildfires allowed woody shrubs andtrees to gradually fill in many areas,and those too barren to supportnatural forest were often planted tored or jack pine, both for timberproduction as well as to stabilize soil.Despite these attempts to convert dryprairies to other uses, a significantamount of dry sand prairie remnantsremain compared to other types ofprairie, though they have stillsuffered a decline by as much as96%. Land managers seeking torestore and maintain dry sand prairieshould seek out remnants andactively keep them in an opencondition by periodic prescribedburns. If remnants are small or havefilled in with woody vegetation,

removal of tree and shrubs may also be necessary.Numerous exotic species such as spotted knapweed(Centaurea maculosa), common St. John�s-wort(Hypericum perforatum), and autumn-olive are alsoproblematic in dry sand prairies, and managers shouldact to halt their spread, contain existing populations,and remove them if at all possible.

Similar CommunitiesDry sand prairie may be confused with woodlandprairie, hillside prairie, oak barrens, oak-pine barrens,and pine barrens. Woodland prairie is a dry-mesiccommunity found on less sandy, slightly more nutrientrich (higher pH) sites with a higher predominance of

big bluestem, little bluestem, and Indiangrass and correspondingly lessPennsylvania sedge. Hillside prairie isalso a dry-mesic community but is foundon open, steep hillsides and bluffs, oftenabove rivers or kettle lakes. Oak barrens,oak-pine barrens, and pine barrens are alldry savanna communities and historicallyhad small pockets of dry sandy prairieinterspersed within them. As savannas,they typically had more than one tree peracre and a canopy cover ranging from 5-60%. For a more detailed overview of drysand prairie, please see the abstractavailable on the MNFI website (Kost2004c).

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Dry sand prairies often occur as open pockets within oak barrens or pine barrens.

Rough blazing star(Liatris aspera)

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Wet prairie Lakeplain wet

prairie

Prairie fen* Wet-mesic

prairie

Lakeplain wet-

mesic prairie

Northern

wet-mesic

prairie

Moisture Wet Wet Wet Wet-mesic Wet-mesic Wet-mesic

Glacial

Landform

Outwash Lakeplain Outwash, Ice-contact

Outwash Lakeplain Outwash

Soil texture loam Fine sandy loam, silty clay

Silty clay loam

Muck (organic) w/ marl deposits

Loam Fine sandy loam Loamy sand to

sand

Soil pH (avg) 6.9 8.0 8.0+ 6.9 8.0 5.8-7.0

Processes

promoting

open conditions

Fire, very high water

table

Fire, fluctuating high water table

Fire, high water table

Fire, seasonally high water

table

Fire, fluctuating seasonally high

water table

Fire, high water table

Region of state SLP Saginaw Bay, St. Clair Delta, extreme SE

SLP interlobate

SLP Saginaw Bay, St. Clair Delta,

extreme SE & SW

NLP, UP

Grank G3 G2? G3 G2 G1? GNR

Srank S2 S1 S3 S2 S1 S1

Mesic

sand

prairie

Mesic

prairie

Woodland

prairie

Hillside

prairie

Dry sand

prairie

Moisture Mesic Mesic Dry-mesic Dry-mesic Dry

Glacial

Landform

Lakeplain, outwash

Outwash Outwash Outwash cut by rivers

or kettle lakes

Outwash, sandy

lakeplain

Soil texture Sandy loam, sand

Sandy loam, loam

Sandy loam Sandy loam, loamy sand

Loamy sand

Soil pH (avg) 5.5 6.2 5.8 5.3 – 6.8 5.1

Processes

promoting open

conditions

Fire, seasonal drought

Fire Fire, drought Fire, dry aspect/ drought

Fire, extreme drought, frost

Region of state SLP Extreme SW

SW, occasional in

SE

mostly SW, also SE, UP

Northern SW, central

NLP

Grank G1? G2 G3 G3 G3

Srank S1 S1 S2 S1 S2

Table 5 (continued). Part B: mesic to dry communities.

Table 5. Comparison of prairie communities in Michigan (listed from wet to dry).Part A: Wet to wet-mesic communities.

*Prairie fen is included due its similar vegetative composition, though it not considered a true prairie communitybecause it occurs in wetlands with organic (peat) soils rather than mineral soils.


Bur oak

plains

Oak openings Lakeplain oak

openings

Oak barrens Oak-pine

barrens

Pine barrens

Moisture Mesic Dry-mesic Dry-mesic Or wet-mesic

Dry Dry Dry

Glacial Landform Outwash Outwash Sandy lakeplain Outwash Outwash Outwash

Soil texture Loam, sandy loam

Outwash, coarse end moraines

Fine sandy loam, loamy fine sand

Sand, loamy sand

Sand, loamy sand

Sand (Grayling

series)

Soil pH (avg) 6.1-7.3 6.1-7.3 7.4-7.8 5.6-6.5 5.6-6.5 4.5-6.0

Processes

promoting open

conditions

Fire Fire, seasonal drought

Fire, seasonally high water table, seasonal drought

Fire, drought Fire, drought Fire, extreme drought, frost

Region of state Extreme SW

SLP Extreme SE SLP Northern SW, central NLP,

UP

Central NLP, UP

Canopy coverage

(estimated)

10%-30% 10%-60% 33% (avg) 5%-60% 5%-60% 20%-40%a

Grank G1 G1 G2? G2? G3 G3

Srank SX S1 S1 S1 S2 S2

Table 6. Comparison of savanna communities in Michigan (listed from wet to dry).

a Suggested range for management in Camp Grayling Pine Barrens Management Plan by Kost et al. 2000.

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Many prairie and savanna remnants occur along railroad grades, where they have been kept openby fires sparked by passing trains.


Savanna Community Descriptions

Bur Oak Plains

General DescriptionBur oak plains was a mesic savanna community with a10-30% canopy cover of bur oaks and a groundcover ofherbaceous plants comprised of species associated withboth open and moderately low-light conditions. Oncefound on level to slightly undulating outwash withloamy soil, the bur oak plains community has beenextirpated from the state and is now known only fromhistorical literature and data derived from severelydegraded sites.

Ecological ProcessesBecause they fell in the middle of the moisturecontinuum, neither being too wet nor too dry, the onlyecological process that maintained a semi-opencondition was frequent fire (ranging from annually toonce every three years). Following the cessation offires, bur oak plains quickly grew up into forest or wereconverted to agriculture. Today no intact remnantsremain of this community in the state. Historically, buroak plains occurred in close conjunction with mesicprairies, grading in and out of one another in a shiftingmosaic dependant on fire frequency and otherdisturbances.

Characteristic PlantsSince bur oak plains have been extirpated from thestate, very little is known about their exact vegetativecomposition. Information is based on historicalaccounts and extrapolations from similar communitiesand degraded remnants in neighboring states. Earlysettlers described bur oak plains as park-like withwidely-spaced trees. Bur oaks (with occasional whiteoaks) likely formed a canopy of 10-30%. Shrubs werenoted as being largely absent, but some fire-tolerantsuch as American hazelnut (Corylus americana) werelikely scattered through the understory. Herbaceousvegetation was a mixture of prairie grasses such as bigbluestem, little bluestem, and Indian grass that likelydominated in more open, high-light areas. Mesicprairie forbs such as prairie coreopsis, mountain-mint,and golden alexanders were also likely common in openareas. Forbs more tolerant of shade were commonlyfound beneath the tree canopies. Early ecologists suchas Curtis (1959) thought the herbaceous plants ofsavannas included species associated with forests aswell as prairies, but modern restorationists such asPackard (1988) believe many species were savannaspecialists, thriving in the mottled light created by thescattered canopy of oaks. Some of those plants that

many have been found in mesic savannas include stateendangered species such white gentian (Gentianaalba), cream wild indigo (Baptisia leucophaea), andshooting-star (Dodecatheon media).

Threats and ConservationWith all bur oak plains thought to be lost or degradedby conversion to agriculture or succession, there maybe little hope for this community in the state.However, efforts should still be made to identify,manage, and expand remnants that may exist,especially adjacent to railroad tracks where passingtrains may have sparked fires frequent enough tomaintain savanna, or adjacent to other existing prairieor savanna sites that may hold promise, such as theedges of cemeteries. If remnants are found, managersshould seek opportunities to expand prairie vegetationthrough prescribed burning and/or planting. Ifplanting, carefully consider what method to use assome techniques may produce dense stands of grasseswith little ecological resemblance to a true, diversesavanna. In addition, if planting in close proximity toan existing remnant, the use of local genotype seed(from the remnant itself and/or other nearby remnantsif at all possible) is strongly recommended. Frequentfire (every 1-3 years) is also absolutely critical tomaintaining prairie vegetation. Lack of fire or lessfrequent burns will result in gradual succession towoody species.

Similar CommunitiesBur oak plains may be confused with several prairie,savanna, or forest communities, including mesicprairie, woodland prairie, oak openings, lakeplain oakopenings, and dry-mesic southern forest. Mesicprairies were likely very similar in plant compositionbut had fewer than one tree per acre (<5% canopy).Woodland prairie is a dry-mesic prairie that sharesome species found in mesic prairie, but also has lessthan one tree per acre. Oak openings is a dry-mesicsavanna community which may have some bur oakscattered throughout the 10-60% canopy, but is usuallydominated by white oaks. Lakeplain oak openingsmay have more bur oaks, but are found exclusively onthe glacial lake plain. Finally, some dry-mesicsouthern forest typically has a mostly closed canopy.However, some sites with loamy soil may actually beclosed-in remnants of bur oak plains, and managersshould check for site indicators like large, open-grownbur oaks (wolf trees), herbaceous savanna indicatorspecies, and circa 1800s vegetation maps that mayindicate former mesic prairie or savanna. For a moredetailed overview of bur oak plains, please see theabstract available on the MNFI website (Cohen2004a).


Oak Openings

General DescriptionOak openings is a dry-mesic savanna community witha 10-60% canopy dominated by white oak and a semi-continuous ground layer of grasses and forbs adaptedto both open prairies and the lower-light conditions ofsavannas. Oak openings were historically found onlevel terrain of outwash plains and coarse-textured endmoraines with sandy loam to dry-mesic loam soils anda slightly acid to neutral pH (6.1-7.3). Once one of themost abundant savanna communities in Michigan, oakopenings have now been nearly extirpated with onlyone small remnant site identified.

Ecological ProcessesFire was the predominant ecological process thatmaintained a semi-open condition within oakopenings. Canopy cover was likely highly variablefrom site to site and within the same site over time.This highly dynamic environment depended largely onfire frequency, with more frequent fires thinning outtrees and shifting sites to a more open, prairiecondition and less frequent fires allowing more treesand shrubs to fill in, gradually turning the savanna intoa more forested community. In sites with moderatelywell-drained, relatively sandy soils, seasonal droughtalso likely played a role in limiting the growth of treesand maintaining an open condition.

Characteristic PlantsSince oak openings have been nearly extirpated fromthe state, very little is known about their exactvegetative composition. Other than a handful ofdegraded remnants, most of them in neighboringstates, information is based largely on historicalaccounts. Early settlers described oak openings aspark-like with widely-spaced trees. White oaks (withoccasional bur and chinquapin oaks) usually form acanopy of 10-60%. Shrub cover varied but includedsome fire-tolerant species such as American hazelnutand New Jersey tea (Ceanothus americanus), as wellas less fire-tolerant species like gray dogwood (Cornusfoemina). Herbaceous vegetation was a mixture ofprairie grasses such as big bluestem, little bluestem,and Indian grass that likely dominated in more open,high-light areas. Dry-mesic prairie forbs such asthimbleweed, butterfly-weed, smooth aster, and frostaster were also likely common in open areas. Forbsmore tolerant of shade were commonly found beneaththe tree canopies. Early ecologists such as Curtis(1959) thought the herbaceous plants of savannasincluded species associated with forests as well asprairies, but modern restorationists such as Packard

(1988) believe many species were savanna specialists,thriving in the mottled light created by the scatteredcanopy of oaks. Some of those plants that many havebeen found in dry-mesic oak openings include statethreatened species such as upland boneset (Eupatoriumsessilifolium), false boneset (Kuhnia eupatorioides),and starry campion (Silene stellata).

Threats and ConservationSince virtually all former oak openings are thought tobe converted to forest or agriculture, or highlydegraded, the primary conservation need is to identify,manage, and expand remnants. If remnants are found,managers should seek opportunities to expand prairievegetation through prescribed burning. Since so fewremnants are thought to exist, other techniques such asselectively thinning closed-in savannas or replantingdry-mesic prairies with scattered oaks may benecessary. Relatively frequent fire is also critical tomaintaining prairie and savanna vegetation. Managersshould use an adaptive management process that seeksa balance between using prescribed fire to promotegrasses and forbs but also allows for the developmentand maintenance of scattered mature oaks.

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Michigan�s only documented high-quality oak openings siteoccurs in an old unmowed cemetary. With restoration ofother degraded remnants, more high-quality sites might oneday be counted among this once abundant community.


Similar CommunitiesCommunities similar to oak openings may includewoodland prairie, bur oak plains, lakeplain oakopenings, oak barrens, and dry-mesic southern forest.Woodland prairies were likely very similar in plantcomposition but had fewer than one tree per acre (<5%canopy). Bur oak plains is state-extirpated mesicsavanna community which may have some white oakscattered throughout the 10-30% canopy, but wasusually dominated by bur oak. Lakeplain oakopenings are quite similar to oak openings but arefound exclusively on the glacial lake plain. Oakbarrens is a drier savanna community with more sandysoils and a high prevalence of black oak in the canopy.Dry-mesic southern forest may have similar canopydominants to oak openings, but typically has a mostlyclosed canopy. However, some sites may actually beclosed-in remnants of oak openings and managersshould check for site indicators like large, open-grownoaks (wolf trees), herbaceous savanna indicatorspecies, and circa 1800s vegetation maps that indicatea high prevalence of mixed oak savanna. For a moredetailed overview of oak openings, please see theabstract available on the MNFI website (Cohen2004b).

Lakeplain Oak Openings

General DescriptionLakeplain oak openings is a savanna community thatoccurs within glacial lakeplains on sand ridges, sandyplains, and slight depressions. Existing in suchvariable topography, lakeplain oak openings are foundalong a wide variety of moisture conditions, with sitesranging from wet and seasonally inundated in moistdepressions to quite dry on former beach ridges. Soilsare commonly very fine sandy loam with a moderatelyalkaline pH (7.4-7.8), but may vary from site to site in

the complex and highly variable glacial lakeplaindeposits. The vegetation is dominated by a variety ofoaks with an average canopy of 33%, while wet to dryprairie grasses and forbs occupy the groundcover.

Ecological ProcessesIn addition to periodic fire, the unique hydrologic cycleof fluctuating Great Lakes water levels, bothseasonally and from year to year historically helpedmaintain the character and composition of lakeplainoak openings. In many flat or low sites, a seasonallyhigh water table inhibited the growth of most trees andshrubs. On former beach ridges, droughty soils werean important factor maintaining open conditions,especially in late summer when water levels typicallywere at their lowest. Since the time of settlement, thelack of frequent fire has lead to gradual succession anda closing in of the canopy, decreasing diversity.Additionally, the hydrology of many sites has beenradically altered by ditching in an attempt to drain theland for farming or development. Beaver activity isalso often cited as an historically important processthat created large impoundments behind dams andresulted in seasonally flooded areas, especially alongstreams in southeast Michigan.

Characteristic PlantsVegetation is highly variable depending on landscapeposition (depression, sand plain, or beach ridge). Oakstypically dominate in all conditions, with bur oak, pinoak (Quercus palustris), and swamp white oak (Q.bicolor) found in poorly drained areas, and black oakand white oak occurring on droughty beach ridges.Other trees and shrubs are even more variable, rangingfrom red ash (Fraxinus pennsylvanica), cottonwood(Populus deltoides), and red maple in wetter sites todry ridges with a predominance of serviceberry(Amelanchier spp.), huckleberry (Gaylussacia

baccata), blueberry (Vaccinium angustifolium), andpasture rose (Rosa carolina). In addition to beingdependent on topography, identifiable herbaceousvegetation also varies by season. In wet sites inspring, sedges (Carex aquatilis, C. lanuginosa, andC. stricta) are most visible; summer may bring suchindicators as colic root (Aletris farinosa), blue-jointgrass, twig-rush, and Baltic rush, while in fall onemight find swamp milkweed (Asclepias incarnata),prairie dock, and prairie cord grass. On dry beachridges, bastard toadflax (Comandra umbellata),hoary puccoon (Lithospermum canescens), andprairie ragwort (Senecio plattensis) might be visiblein spring, with summer dominated by thimbleweed,butterfly weed, and woodland sunflower(Helianthus divaricatus), and fall bringing on

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Lakeplain oak openings support a wide variety of grasses and forbsbeneath an open canopy of bur oak (Quercus macrocarpa).


characteristic prairie species such as big bluestem,little bluestem, Indian grass, blazing star (Liatrisaspera, L. spicata), and stiff goldenrod (Solidagorigida).

Threats and ConservationSince the time of European settlement, many lakeplainoak openings have been lost due to conversion toagriculture, development, or have beendrastically altered by fire suppression anddisruption of hydrology. Land managersseeking to restore lakeplain oak openingsshould focus efforts on expanding existingremnants through the use of prescribedburning and where former savanna hasconverted to forest, careful and gradualthinning of the canopy. Restoration ofhydrology may also aid in the restoration ofsome sites. As in most communities, controlof invasive species, in particular shrubs suchas common and glossy buckthorn is also apriority.

Similar CommunitiesSimilar communities to lakeplain oakopenings include lakeplain wet prairie,

lakeplain wet-mesic prairie, bur oak plains and oakopenings. Both wet and wet-mesic lakeplain prairiesmay have very similar herbaceous vegetation andlikely graded in and out of lakeplain oak openingsbased on fire frequency, hydrology, and topography.However, like all prairies, they have less than one treeper acre (<5% canopy). Bur oak plains and oakopenings are mesic and dry-mesic savannacommunities, respectively, and are also dominatedoaks. While they may have similar groundcover, theyare found primarily on glacial outwash and never onthe glacial lakeplain. For a more detailed overview oflakeplain oak openings, please see the abstractavailable on the MNFI website (Cohen 2001a).

Oak Barrens

General DescriptionOak barrens is a dry savanna community foundprimarily in southern Lower Michigan on droughtyglacial outwash plains. White and black oaks form thedominant canopy, which ranges from 5 to 60%, withshort, sometimes sparse layer of grasses and forbs.Soils are typically infertile, coarse-textured sand with amoderately acid pH (5.6 � 6.5).

Ecological ProcessesWhile periodic fire was important in promoting theherbaceous plant community, droughty soils alsohelped maintain an open condition by limiting treeestablishment and growth to slow-growing, droughtand fire-tolerant oaks. Canopy cover was likely highlyvariable from site to site and within the same site overtime. This highly dynamic environment depended bothon soil characteristics and fire frequency, with morefrequent fires thinning out trees and shifting sites to a

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Pennslyvania sedge (Carex pensylvanica) and little bluestem (Andropogonscoparius) dominate the ground cover beneath black and white oak in atypical oak barrens.

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Remnant lakeplain oak openings with a partially closedcanopy are often restorable with prescribed fire.


more open, prairie condition andless frequent fires allowing moretrees and shrubs to fill in, graduallyturning the savanna into a moreforested community.

Characteristic PlantsOak barrens are highly variable invegetation structure, ranging fromnearly completely open, park-likestands with only a 5% canopy ofwidely spaced trees to relativelydense thickets of trees and brushforming up to a 60% canopy. Theoverstory is dominated by white andblack oaks, with pignut hickory(Carya glabra) often also present.Characteristic shrubs includehazelnut, serviceberry, sweet-fern(Comptonia peregrina),huckleberry, blueberry, and prairie willow (Salixhumilis). The ground layer is often dominated bygraminoids, including little bluestem, Pennsylvaniasedge, poverty grass, hair grass, and needle grass(Stipa avenacea and S. spartea). Forbs are oftensparse, but may include dry savanna specialists such aswild lupine (Lupinus perennis), goats-rue (Tephrosiavirginiana), false foxglove (Aureolaria spp.), andcolumbo (Swertia caroliniensis) in addition to prairiespecies like blazing star (Liatris aspera and L.cylindracea), bush-cover (Lespedeza hirta, L.capitata), and wild bergamot (Monarda fistulosa).

Threats and ConservationLike many other prairie and savanna communities, oakbarrens have sharply declined as a result of firesuppression and conversion to other land uses.Because the soils are relatively infertile, many sites

once cleared for agriculture have beenabandoned and have returned to asemi-natural, though degraded,condition. Maintenance of existingremnants and restoration of degradedsites through the use of prescribedburning is recommended. Sites thathave succeeded into more closed-canopy conditions may also benefitfrom careful, selective thinning of thecanopy. Control of both herbaceousinvasive species (such as spottedknapweed) and woody invasivespecies (particularly autumn-olive) isalso often necessary. Wherewildflower diversity has severelydeclined, replanting key species suchas lupine may be beneficial if severalyears worth of other management failsto promote dormant plants orstimulate the native seed bank.

Similar CommunitiesOak barrens may be confused with dry sand prairie,oak openings, oak-pine barrens, and dry southernforest. Dry sand prairie is a dry prairie community thathistorically existed in close proximity with oak barrenswith very nearly identical herbaceous species.However, like all prairies, is has less than one tree peracre (<5% canopy). Oak openings is a dry-mesicsavanna community found on slightly more productive,less droughty soils, and was historically dominated bywhite and bur oak, with more dry-mesic ground floraincluding higher proportions of big bluestem andIndian grass, and less Pennsylvania sedge. Oak-pinebarrens is a dry savanna that may have very similarvegetation to oak barrens, but has a co-dominance ofwhite, red, or jack pine (Pinus strobus, P. resinosa, P.banksiana) and exists primarily in northern LowerMichigan and the UP rather than southern LowerMichigan. Finally, dry southern forest may havesimilar canopy dominants to oak barrens, but typicallyhas a mostly closed canopy. However, some sites mayactually be closed-in remnants and managers shouldcheck for site indicators like large, open-grown oaks(wolf trees), herbaceous savanna indicator species, andcirca 1800s vegetation maps that indicate a highprevalence of black oak barrens. For a more detailedoverview of oak barrens, please see the abstractavailable on the MNFI website (Cohen 2001b).

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Spotted knapweed (Centaureamaculosa), an exotic invasive species

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Wild bergamot (Monarda fistulosa)


Oak-pine Barrens

General DescriptionOak-pine barrens is a dry savanna community foundprimarily in northern Lower Michigan and the UP ondroughty glacial outwash plains. Canopy coverage isvariable, ranging from 5-60%, and is dominated bywhite, black, and northern pin oak (Quercusellipsoidalis) along with white, red, and jack pine. Theherbaceous layer is typically short and dominated byPenn sedge, and soils are typically infertile, coarse-textured sand with a moderately acid pH (5.6 � 6.5).

Ecological ProcessesLow-intensity fire and periodic drought are the keyprocess that maintained an open savanna environmentin oak-pine barrens. Fires burning adjacent prairiehistorically spread into surrounding woodlands,burning out fire-intolerant trees and shrubs and overtime, thinning the canopy. This in conjunction withperiodic drought on the sandy, infertile soils inhibitedtree growth and development and helped maintain apartial canopy coverage of oaks and pines.

Characteristic PlantsLike many savannas, oak-pine barrens can be highlyvariable in structure depending on site-level soilcharacteristics, land use history, and fire frequency.White, black, and northern pin oak typically co-dominate with white, red, and jack pine to form acanopy that ranges from 5% to 60%. Shrubs aresimilar to other dry barrens, and can include hazelnut,serviceberry, huckleberry, blueberry, and prairiewillow. Herbaceous vegetation is very similar to oakbarrens, being typically short and sometimes alsosparse, and is dominated by little bluestem and Pennsedge with lesser amounts of big bluestem. Other

grasses and forbs typically include poverty grass, hairgrass, sand tickseed (Coreopsis lanceolata), woodlandsunflower (Helianthus divaricatus), and sky-blue aster(Aster oolentangiensis). Ground layer diversity isoften low and may be dominated almost exclusively byPenn sedge in areas that have been grazed and/or firesuppressed.

Threats and ConservationLike many other prairie and savanna communities,oak-pine barrens have declined as a result of firesuppression and conversion to other land uses.Because the soils are relatively infertile, many sitesonce cleared for agriculture have been abandoned andhave returned to a semi-natural, though degraded,condition. Maintenance of existing remnants andrestoration of degraded sites through the use ofprescribed burning is recommended. Sites that havesucceeded into more closed-canopy conditions mayalso benefit from careful, selective thinning of thecanopy. Control of both herbaceous invasive species(such as spotted knapweed) and woody invasivespecies (particularly autumn-olive) is also oftennecessary.

Similar CommunitiesCommunities similar to oak-pine barrens include drysand prairie, oak openings, oak barrens, pine barrens,and dry northern forest. Dry sand prairie is a dryprairie community that historically existed in closeproximity with oak-pine barrens with very nearlyidentical herbaceous species. Like all prairies, it canbe differentiated by having less than one tree per acre(<5% canopy). Oak openings is a dry-mesic savannacommunity found in southern Lower Michigan onslightly more productive, less droughty soils, and washistorically dominated by white and bur oak. Oakbarrens is a dry savanna that may have very similarvegetation to oak-pine barrens, but is located primarilyin southern Lower Michigan and is dominated bywhite and black oak with little to no pine component.Pine barrens is also a dry savanna community, but asthe name implies is dominated by red and jack pinewith few oaks. Dry northern forest may have similarcanopy dominants to oak-pine barrens, but typicallyhas a more closed canopy. Since many sites mayactually be closed-in remnants, managers should checkfor site indicators like large, open-grown oaks (wolftrees), herbaceous savanna indicator species, and circa1800s vegetation maps that indicate a high prevalenceof oak-pine barrens. For a more detailed overview ofoak-pine barrens, please see the abstract available onthe MNFI website (Cohen 2000).

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Oak-pine barrens often have a partially open canopy and occuron dry, sandy soils in northern Michigan.


Pine Barrens

General DescriptionPine barrens is a dry coniferous savanna dominated byscattered jack pine located in northern LowerMichigan and the UP. Occurring on level to rollingglacial outwash, soils are typically very infertile,strongly acidic (pH 4.5 � 6.0), coarse-textured sands.

Ecological ProcessesThe pine barrens and surrounding jack pine forests areknown for infrequent, catastrophic, stand-replacingfires, largely as a result of fire-promoting adaptationsof jack pine such as flaky, thin bark, volatile oils in theneedles, and serotinous cones (only opening followingextreme heat). Under some circumstances, low-intensity fires that burned primarily herbaceousvegetation also likely occurred. Pine barrens typicallydominated the most frequently burned and mostinfertile sites. In addition to periodic severe drought,frosts are also common in low depressions (frostpockets) and can occur throughout thegrowing season, severely limiting growthof deciduous trees and shrubs.

Characteristic PlantsPine barrens are typically dominated byirregularly scattered jack pine, withlesser amounts of northern pin oak.Shrubs may range from sparse clumps toextensive colonies and includecharacteristic species like bearberry,blueberry, and sweet-fern. Though not ashrub, bracken fern (Pteridiumaquilinum) is another common plantreaching the a similar height (2-4 feet).Groundcover is often dominated bygrasses and sedges such as Penn sedge,little bluestem, and poverty grass. Forbs

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Pine barrens occur on sandy rolling terrain with scattered jack pineand a groundcover of Pennslyvania sedge and little bluestem.

are typically sparse but may include indicator specieslike birdfoot violet (Viola pedata), rough blazing star(Liatris aspera), and Hill�s thistle (Cirsium hillii).

Threats and ConservationFire suppression is the primary threat to remainingpine barren remnants. Due to the catastrophic natureof wildfires in jack-pine dominated areas, social andpolitical concern over potential dangers of fireremains high throughout the pine barrens region. Inaddition to fire suppression, many areas of formerpine barrens are under active timber management, andsites are typically mechanically furrowed andreplanted following harvest. Natural succession andthe planting of trees into barrens has led to a declineof species dependent on natural, irregular openings.Rare plant species in particular are threatened by thefurrowing of the ground and dense plantations.Managers seeking to maintain and restore pinebarrens should aim for canopy coverage of 10-40%(Kost et al. 2000). If possible, prescribed fire shouldbe carefully used to stimulate the herbaceousvegetation and seed bank.

Similar CommunitiesSimilar communities include dry sand prairie, oak-pinebarrens, and dry northern forest. Dry sand prairie is adry prairie community that historically existed in closeproximity with pine barrens with nearly identicalherbaceous species. Like all prairies, it can bedifferentiated by having less than one tree per acre(<5% canopy). Oak-pine barrens is also a dry savannathat may have very similar vegetation to pine barrens,but has a co-dominance of white, black, and northernpin oak in addition to a white, red, and jack pine. Drynorthern forest may have similar canopy dominants to

pine barrens, but typically has a moreclosed canopy. Since some sites mayactually be closed-in remnants, managersshould check for herbaceous indicatorspecies and circa 1800s vegetation mapsthat indicate a high prevalence of pinebarrens. For a more detailed overviewof pine barrens, please see the abstractavailable on the MNFI website (Comer1996).

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Little bluestem(Andropogon scoparius)


Abrams, M.D. 1992. Fire and the development of oakforests. BioScience 42(5): 346-353.

Albert D.A. and M.A. Kost. 1998a. Naturalcommunity abstract for lakeplain wet prairie.Michigan Natural Features Inventory, Lansing, MI.4 pp.

Albert D.A. and M.A. Kost. 1998b. Naturalcommunity abstract for lakeplain wet-mesicprairie. Michigan Natural Features Inventory,Lansing, MI. 4 pp.

Apfelbaum, S.I and A.W. Haney. 1991. Managementof degraded oak savanna remnants in the upperMidwest: Preliminary results from three years ofstudy. Proceedings Oak Woods ManagementWorkshop. pp. 81-89.

Chapman, K.A. 1984. An EcologicalInvestigation of Native Grassland In SouthernLower Michigan. M.A. Thesis. WesternMichigan University, Kalamazoo, MI. 235 pp.

Cohen, J.G. 2000. Natural community abstract foroak-pine barrens. Michigan Natural FeaturesInventory, Lansing, MI. 6 pp.

Cohen, J.G. 2001a. Natural community abstract forlakeplain oak openings. Michigan NaturalFeatures Inventory, Lansing, MI. 9 pp.

Cohen, J.G. 2001b. Natural community abstract foroak barrens. Michigan Natural Features Inventory,Lansing, MI. 8 pp.

Cohen, J.G. 2004a. Natural community abstract forbur oak plains. Michigan Natural FeaturesInventory, Lansing, MI. 13 pp.

Cohen, J.G. 2004b. Natural community abstract foroak openings. Michigan Natural FeaturesInventory, Lansing, MI. 13 pp.

Comer, P.J.. 1996. Natural community abstract forpine barrens. Michigan Natural FeaturesInventory, Lansing, MI. 3 pp.

Comer, P.J., D.A. Albert, H.A. Wells, B.L. Hart, J.B.Raab, D.L. Price, D.M. Kashian, R.A. Comer, andD.W. Scheun. 1995. Michigan�s presettlementvegetation, as interpreted from the General LandOffice Surveyes 1816-1856. Michigan NaturalFeatures Inventory, Lansing, MI. Digital map.

Copeland, T.E., W. Sluis and H.F. Howe. 2002. Fireseason and dominance in an Illinois tallgrassprairie restoration. Restoration Ecology 10:315-323.

Coppedge, B.R., D.M. Engle, C.S. Teopfer, and J.H.Shaw. 1998. Effects of seasonal fire, bisongrazing and climatic variation on tallgrass prairievegetation. Plant Ecology 139: 235-246.

Curtis, J.T. 1959. Vegetation of Wisconsin: AnOrdination of Plant Communities. University ofWisconsin Press, Madison, WI. 657 pp.

Eagle, A.C., E.M. Hay-Chmielewski, K.T. Cleveland,A.L. Derosier, M.E. Herbert, and R.A. Rustem, eds.2005. Michigan�s Wildlife Action Plan. MichiganDepartment of Natural Resources. Lansing, Michi-gan. 1592 pp. http://www.michigan.gov/dnrwildlifeactionplan

Fuhlendorf, S.D. and D.M. Engle. 2001. Restoringheterogeneity on rangelands: Ecosystemmanagement based on evolutionary grazingpatterns. BioScience 51:8. pp 625-632.

Heiligmann, R.B. 1997. Controlling UndesirableTrees, Shrubs, and Vines in Your Woodland. OhioState University Extension Fact Sheet F-45-97.Ohio State University. Columbus, OH. 3 pp.

Howe, H.F. 1994. Response of early- and late-flowering plants to fire season in experimentalprairies. Ecological Applications 4:121-133.

Howe, H.F. 1995. Succession and fire season inexperimental prairie plantings. Ecology 76:1917-1925.

Jamison, B.E., S.A. Leis, and N.L. Murray. 2005.Vegetation structure in patch burn grazingmanagement units on tallgrass prairie remnants insouthwestern Missouri. Abstract and oralpresentation at 2005 Midwest Fish & WildlifeConference, Grand Rapids, MI.

LITERATURE CITED


Kline, V.M. 1997. Orchards of oak and a sea of grass.Pp. 3-21 in S. Packard and C.F. Mutel, eds., TheTallgrass Restoration Handbook. Island Press,Washington, D.C.

Kost, M.A. 2004a. Natural community abstract formesic prairie. Michigan Natural FeaturesInventory, Lansing, MI. 10 pp.

Kost, M.A. 2004b. Natural community abstract forwoodland prairie. Michigan Natural FeaturesInventory, Lansing, MI. 8 pp.

Kost, M.A. 2004c. Natural community abstract fordry sand prairie. Michigan Natural FeaturesInventory, Lansing, MI. 9 pp.

Kost, M.A., P.J. Higman, D.L. Cuthrell, and J.L.Cooper. 2000. North Camp Grayling PineBarrens Management Plan. Report No. 2000-02.Michigan Natural Features Inventory, Lansing, MI.67 pp.

Middleton, B. 2004. Cattle Grazing and Its Long-term Effects on Sedge Meadows. USGS FactSheet 2004-3027. 4 pp.

Molt, C. 1990. Restoring the prairie. BioScience40:804-809.

Monsanto Co. 2001. Roundup Pro Specimen Label.EPA Reg. No. 524-529. Monsanto Co., St. Louis,MO.

Nuzzo, V. 1986. Extent and status of Midwest oaksavanna: presettlement and 1985. Natural AreasJournal 6(2): 6-36.

Packard, S. 1988. Just a few oddball species:Restoration and the rediscovery of the tallgrasssavanna. Restoration and Management Notes11(1): 13-21.

Packard, S. 1993. Restoring oak ecosystems.Restoration and Management Notes 11(1):5-16.

Packard, S. 1997. Restoration Options. Pp. 47-62 inS. Packard and C.F. Mutel, eds., The TallgrassRestoration Handbook. Island Press, Washington,D.C.

Panzer, R. 2003. Importance of In Situ Survival,Recolonization, and Habitat Gaps in the PostfireRecovery of Fire-sensitive prairie insect species.Natural Areas Journal 23:14-21.

Pauly, Wayne R. 1988. How to manage small prairiefires. Dane County Park Commission. Madison,WI.

Pergams, O.R.W. and J.E. Norton. 2006. Treating asingle stem and kill the whole shrub: a scientificassessment of buckthorn control methods. NaturalAreas Journal 26:300-309.

Richburg, J.A. 2005. Timing Treatments To ThePhenology of Root Carbohydrate Reserves toControl Woody Invasive Plants. DoctoralDissertation. University of Massachusetts,Amherst, MA. 54 pp.

Sparks, J.C., R.E. Masters, D.M. Engle, M.W. Palmer,and G.A. Bukenhofer. 1998. Effects of lategrowing-season and late dormant-seasonprescribed fire on herbaceous vegetation inrestored pine-grassland communities. Journal ofVegetation Science 9:133-142.

Spieles, J.B., P.J. Comer, D.A. Albert, and M.A. Kost.1999. Natural community abstract for prairie fen.Michigan Natural Features Inventory, Lansing, MI.4 pp.

Transeau, E.N. 1935. The Prairie Peninsula.Ecology: Vol. 16(3): 423�437.

Weir, T.L., H.P. Bais, and J.M. Vivanco. 2003.Intraspecific and Interspecific InteractionsMediated by a Phytotoxin, (�)-Catechin, Secretedby the Roots of Centaurea maculosa (SpottedKnapweed). Journal of Chemical Ecology29:2397-2412.

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