iowa's biological communities -

Iowa's Biological Communities Series

Iowa Association of Naturalists

Iowa's BiologicalCommunities

Iowa's Biological Communities SeriesIowa's natural beauty has long been a great factor in drawing people to the state. But there is more tothat beauty than meets the eye. To assist Iowa educators in teaching their students about thecomplexities of Iowa woodlands, wetlands, waterways, and prairies, the Iowa Association of Naturalistshas produced a series of booklets which offer a basic, understandable overview of Iowa biologicalcommunities. The five booklets in this series are:

Iowa’s Biological Communities (IAN-201)Iowa Woodlands (IAN-202)Iowa Prairies (IAN-203)Iowa Wetlands (IAN-204)Iowa Waterways (IAN-205)

Editorial BoardText: Dan CohenIllustrations: Mark MüllerDesign and Layout: Dan Cohen Writing and Publications ServicesPublisher: Iowa Association of Naturalists

The Iowa's Biological CommunitiesSeries is published by IAN with majorfunding from the ResourceEnhancement And Protection (REAP)Conservation Education Board(September, 2001).

Review CommitteeDan Cohen, Executive Director, Buchanan County Conservation BoardDetra Dettmann-Easler, Deputy Director, Louisa County Conservation BoardAnita Fisher, Naturalist, Emmet County Conservation BoardPam Holz, Naturalist, Washington County Conservation BoardJim Pease, Extension Wildlife Specialist, Iowa State UniversityMelanie Perry, Naturalist, West Des Moines Park and Recreation DepartmentDiane Pixler, Naturalist, Marshall County Conservation BoardLinda Zaletel, Naturalist, Story County Conservation Board

The Iowa Association of Naturalists (IAN) is a nonprofit organization ofpeople interested in promoting the development of skills and educationwithin the art of interpreting the natural and cultural environment. IANwas founded in 1978 and may be contacted by writing the ConservationEducation Center, 2473 160th Rd., Guthrie Center, IA 50115, 515/747-8383.


Iowa's Biological Communities is one in a series of five booklets that are part of theIowa's Biological Communities Series. The booklets in the series include:

Iowa's Biological CommunitiesIowa’s Biological Communities (IAN-201)Iowa Woodlands (IAN-202)Iowa Prairies (IAN-203)Iowa Wetlands (IAN-204)Iowa Waterways (IAN-205)

The Iowa Association of Naturalists has produced six other booklet series that provide readers with a clear,understandable overview of topics concerning the Iowa environment and conservation. The bookletsincluded in each of the other five series are listed below.

Iowa Physical Environment SeriesIowa Weather (IAN-701)Iowa Geology and Fossils (IAN-702)Iowa Soils (IAN-703)

Iowa Wildlife SeriesIowa Mammals (IAN-601)Iowa Winter Birds (IAN-602)Iowa Nesting Birds (IAN-603)Iowa Reptiles and Amphibians (IAN-604)Iowa Fish (IAN-605)Iowa Insects and Other Invertebrates (IAN-606)

Iowa’s Natural Resource HeritageChanging Land Use and Values (IAN 501)Famous Iowa Conservationists (IAN 502)Iowa’s Environmental Laws (IAN 503)

Iowa Wildlife and PeopleIowa Wildlife Management (IAN-401)Keeping Iowa Wildlife Wild (IAN-402)Misconceptions About Iowa Wildlife (IAN-403)State Symbols of Iowa (IAN-404)Iowa Food Webs and Other Interrelationships (IAN-405)Natural Cycles in Iowa (IAN-406)Iowa Biodiversity (IAN-407)Adapting to Iowa (IAN-408)

Iowa PlantsIowa’s Spring Wildflowers (IAN-301)Iowa’s Summer and Fall Wildflowers (IAN-302)Benefits and Dangers of Iowa Plants (IAN-303)Iowa’s Trees (IAN-304)Seeds, Nuts, and Fruits of Iowa Plants (IAN-305)Iowa’s Mushrooms and Other Nonflowering Plants (IAN-306)Iowa’s Shrubs and Vines (IAN-307)

Iowa Environmental IssuesIowa Habitat Loss and Disappearing Wildlife (IAN-101)Iowa Air Pollution (IAN-102)Iowa Water Pollution (IAN-103)Iowa Agricultural Practices and the Environment (IAN-104)People, Communities, and Their Iowa Environment (IAN-105)Energy in Iowa (IAN-106)Iowa Waste Management (IAN-107)

√ Booklets may be orderedthrough Iowa State

University Extension Service ata cost of $1.00 per booklet.When ordering, be sure to usethe IAN number to the right ofeach listed booklet title.Please send written orders andpayment to:

ISU Extension ServicePrinting and Publications BuildingIowa State UniversityAmes, IA 50011

This publication is printedon recycled paper.


Iowa’s Biological Communities

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Iowa’s BiologicalCommunities

owa was once coveredby vast prairiegrasslands and open

savannas. Thick woodlandsbordered the many riversand streams. A large varietyof wildlife lived in Iowa’sprairies, woodlands,wetlands, and waterways.But Iowa’s landscape hasundergone drastic changes inthe past 150 years. Naturalbiological communities havebeen greatly reduced andreplaced by farms, towns,industries and roads. The prairiesand wetlands are nearly gone, andrivers and streams have been greatly changed tomeet human demands. And less than a third ofIowa woodlands remain.

Formation of Iowa’s biological communitiesA biological community is more than a place withgrasses or trees. The community includes all theliving things - their interactions and diversity. AsIowa’s woodlands, prairies, wetlands, andwaterways became established, a variety of plantsand animals became adapted to the special,evolving characteristics of each ecosystem.Climate, soils, topography, and moisture madeeach a special place. When European settlersarrived in what is now Iowa, they encounteredvibrant biological communities with astoundingplant and animal life.

I



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Iowa’s biologicalcommunities became a partof our modern landscapefollowing the retreat ofthe most recent glaciersthat covered much of Iowa10,000-14,000 years ago. Inthe region of north andcentral Iowa known as theDes Moines Lobe, glaciersflattened and scraped thelandscape, leaving behindnumerous depressions filledwith water. Left behindwere thousands of wetlands

of various sizes. Streams slowly meanderedthrough the flat terrain.

Where recent glaciers did not flatten thelandscape, streams have cut well-defined beds inthe land. In these older landscapes, rocky ledgesand stone cliffs sometimes border the waterways.The gently rolling hills and deep river valleys ofsouthern Iowa are part of an older landscape. TheNortheast Iowa Driftless Area is the oldestlandscape in Iowa. Cool water rushes and tumblesover rocks and gravel down steep slopes in thishilly region.

The climate began to warm as the glaciersretreated. A prairie ecosystem, dotted with smallprairie marshes called potholes, began to dominatethe state. Dense root systems and the ability tosurvive fire allowed prairie plants to hold theirground in the drier climate, excluding most treesand other woody plants. Iowa’s woodlands were,for the most part, restricted to areas where moremoisture was available.

Des MoinesLobe

Periods of glaciation shaped thelandscape of Iowa. The flattestlandscape is in the area of the DesMoines Lobe. The rest of the stateis hillier with better defined riversand streams.



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A state of changeWoodlands, prairies, wetlands, and waterways aredynamic biological communities. Each exists in aconstant state of change. A predictable series ofchanges in vegetation over time is commonlyreferred to as succession. Each stage ofsuccession provides different types of habitat forplants and animals.

A woodland may begin as a grassland, pasture, orparcel of disturbed land. A few shrubs andgrassland-adapted trees begin to grow in the area.Next, the land is covered by a thick woodlandgrowth of fast-growing trees and shrubs that isdifficult to walk through. The climax vegetation,or old-growth, for a typical Iowa woodland has verylarge, leafy trees that shade out much of thewoodland floor. The process moves back and forthbetween stages, making woodlands dynamic withchanges in plant and animal life.

Prairies also change over time. A thick mat ofplant litter slowly accumulates and slows thegrowth of prairie plants. These dense prairies donot offer wildlife enough space to move around,find cover, and locate food. In the absence of fireand left unmanaged, a prairie area may slowly betaken over by shrubs and trees.

Biological communities are constantly changing. Throughthe natural process of succession, grasslands sometimesgive way to woodlands.



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There is also a cyclical process of successionin a wetland marsh. In the open waterstage, when a basin is full of water, thecommon plants are often submersedunderwater. Usually within 20 years, therecomes a period of drought and the wetlandbecomes a dry marsh. Seeds of emergentplants sprout in the exposed soil and, whenrainfall returns, the wetland is transformedinto a dense marsh of cattails and reeds.The next stage, called the hemi-marshstage, has the most diversity of plants andanimals and occurs when emergent plantsbecome fewer. This stage is characterizedby having approximately as much emergentgrowth as open water. With normalrainfall and continued loss of emergentplants, the marsh returns to the openwater stage and the cycle continues.

Rivers and streams are also constantly changing.If a person stands on a bluff bordering theMississippi River in eastern Iowa and looks to theeast, he or she will see a broad, flat floodplainseparating the hills of Iowa and Illinois orWisconsin. This floodplain was formed over manyyears as the Mississippi River grew and shrank,meandered and formed oxbows. Large rivers andstreams often form these wide wetland floodplains.

Natural disturbances and human activity affectchanges in biological communities and wildlifehabitat. Succession in a woodland may beinterrupted many times by disturbances such asfire, clear-cutting, wind storms, disease epidemics,or human woodland management techniques. In aprairie, fire, grazing, mowing, and haying affectsuccession. Floods, dams, channelization, periodsof drought, muskrat activity, and wetland drainingor filling all affect the natural, cyclical changes ofa wetland. Dams, channelization, erosion,pollution, and rainfall may be forces that changerivers and streams.

The hemi-marsh wetland stage hasthe most diversity of plants andanimals. Muskrats are an integraloccupant of these wetlands.



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Iowa’s woodlands were historically found inareas sheltered from direct sunshine andstrong winds where more moisture was

available. In these areas, trees could establishthemselves and outcompete grasses that coveredmost of the state. Iowa rivers and streams werebordered by a thick woodland corridor. Theeastern, southern, and especially northeasternparts of Iowa were more heavily forested than therest of the state. Today there are fewer woodlands,but they still favor the same climate and maintainthe same general distribution. Iowa’s biologicalcommunities have all been greatly reduced, butwoodlands are by far the most common of Iowa’sremaining biological communities. Approximately28 percent of Iowa’s original forest cover remains.

Woodland plantsA large variety of trees, shrubs, vines, and flowersmay be found growing in Iowa woodlands. Theseplants are characterized by growing in eitherupland or bottomland woodlands, although theymay overlap. Upland woodlands are most oftenfound on hilltops and drier south and west slopes.They often contain large oaks and hickories – treesbetter adapted to sunlight and drier conditions.When these trees grow large, their leafy canopiesshade the forest floor. Shade-tolerant sugarmaples and basswoods sometimes take over areaspreviously covered by oaks and hickories.

Along streams and on more damp north andeast sides of slopes are Iowa’s bottomlandwoodlands. Ravine bottoms often containcottonwood, silver maple, and green ash trees, withbasswoods growing on hillside slopes and willowsbordering stream banks.

The woodland community

Upland woodlands, oftendominated by oak and hickoryor sugar maples, are a differenttype of plant community thanbottomland woodlands, which oftenare dominated by cottonwood andsilver maple.



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Savannas are areas composed of a mixture ofmature woodland and grassland vegetation. Themost common savanna tree is the burr oak, whichhas a deep tap root and thick bark, well-adapted tosurviving hot prairie fires.

The heavily wooded Driftless Area in NortheastIowa contains native red cedar, white pine, balsamfir, and prostrate juniper – evergreens that aremore common in Minnesota and Canada but rarelynative in the rest of Iowa. A very rare and uniquetype of habitat is found in these woodlands. Icecaves and cold air slopes are found here, and arehomes for endangered plants and animals.

Forest plants grow in layers. Smaller understorytrees and shrubs grow beneath large canopy trees.Most Iowa woodlands once were pastured, andthorny bushes and other plants not eaten by cattleare now common in our woodland shrub layers.Examples include gooseberries, raspberries, honeylocust, hawthorn, and prickly ash. Many vines,such as Virginia creeper and wild grape, climb ontrees and shrubs and on the woodland floor. Awoodland vine to be aware of is poison ivy. It isvery common, especially in our floodplain forests.

Early in spring, woodlands come to life assmall patches of color poke up through thelitter of dead leaves and fallen twigs. Thesefirst flowers of early spring are calledephemerals because the are short-lived, andare some of the most beautiful and numerousof the woodland flowers. Bloodroot, hepatica,and Dutchman’s breeches bloom before bigtrees form their thick canopy that shades thewoodland floor. These flowers are followed bymany others, including May apple, Virginiawaterleaf, and columbine. To find out moreabout identifying Iowa’s beautiful woodlandwildflowers, refer to a field guide.

Sil-vermaple

Bloodroot is anearly springephemeral flower.



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Woodland animalsFrom the high canopy of an Iowa woodland, a fewof Iowa’s most fascinating birds may search thelandscape for their food. Hawks use high treetopsfor nesting or perching, and hunt as they soarabove woodland edges. Within the woodland, owlsperch or nest in the canopy as they listen quietly inthe still night for the movements of their prey. Theunderstory may appear to be a circus trapeze act offlying songbirds, leaping squirrels, and climbingwoodpeckers. Look for leafy squirrel nests in thetreetops and woodpecker holes in standingdead trees.

For much of summer, woodland shrubsare the grocery store of an Iowawoodland. A variety of small birds dartin and out of shrubs, eating berries andinsects and taking advantage of thickshrub cover for shelter. Deer browse onleaves in the shrub layer, well-protectedamong thickets.

Chipmunks and mice scurry amongrocks and logs of the woodland floor in search offallen nuts, seeds, and berries. Toads stay in themoist woodland floor and eat crickets and othercrawling or low-flying insects. Snakes and grayfoxes hunt for smaller animals that seekconcealment among low-growing plants. Raccoons,opossums, and skunks prowl for small mammalsand invertebrates, and fallen nuts, seeds, andberries.

The strange world of the woodland basement ishome to a variety of obscure invertebrates. Thesesmall creatures may have no eyes or many eyes, ahundred legs or no legs, antennae, hairs, slime, orany combination of characteristics. Manyimportant decomposition animals such as ants, pillbugs, and larval insects live in the woodlandbasement. Tunnels crisscross under the groundand reveal the movements of moles.



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The prairie community

Prairies once dominated the Iowalandscape. Approximately 85 percent ofIowa was covered by a mixture of prairie

grasses and flowers. Wetlands dotted the prairielandscape, and a large variety of wildlife lived inIowa’s prairies and prairie wetlands. WhenEuropean settlers first encountered the prairies ofIowa, they had difficulty finding words to expresswhat they saw. The vast sea of grasses andflowers had no counterpart in Europe. “Prairie,”the French word for “meadow,” was adopted todescribe the awesome spectacle which first greetedsettlers as they moved west out of the easternforests.

Prairie plantsWhereas trees dominate and define a woodland,grasses dominate and define a prairie. In general,tall grasses and sedges are found in moderate todamp soils and shorter grasses are more commonin dry or sandy soils. At least 72 species of grassesare known to grow in Iowa’s prairies.

Vast areas of the Iowa prairie, especially in theprairie pothole region, were historically damp andcontained many wetlands. These are the areas

where the tallest grasses grow.Tall grasses, including bigbluestem, Indian grass, and switchgrass, are common in many prairieareas. Wetter areas contain sedgesand other wetland plants. Shortergrasses, such as little bluestem,sideoats grama, and tall dropseed,are more typical of dry or sandyprairies and historically were lesscommon in Iowa.



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Prairies are more than a sea of grasses. They areplaces of beauty, filled with the colors of showyflowers. A parade of prairie wildflowers begins inApril and marches through to October. Prairiewildflowers have adapted to life in an environmentin the open, exposed to sun and wind. Althoughcertain plants may be better adapted to drier orwetter conditions, prairie wildflowers can be foundgrowing in all types of prairies.

Prairie animalsAlthough a sea of grasses may identify a prairie ata glance, prairie animals are an integral part of anIowa prairie. There are areas scattered throughoutthe state where people have planted variousgrasses and a wildflowers in an attempt todemonstrate what a prairie may have looked like.Appearances aside, however, in a real prairiecommunity, plants and animals interact to make abiological community that is diverse and complex.

Animals depend on prairie plants andother prairie animals and often usespecific types of prairies. Historically,Iowa prairies contained a largevariety of wildlife specially adaptedto life in the open grasslands.Bison, elk, and wolves once lived inIowa. It is unlikely that prairiedogs or black-footed ferrets everlived in Iowa, but they werecommon in the westernshortgrass prairies. Tallgrasses and loamy soilsprovide a home forsmaller mammalssuch as pocketgophers, groundsquirrels,grasshoppermice, and badgers.

Many large prairie wildlife speciesno longer live in Iowa.



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Bobolink

In winter, prairie plants provide a durable one tothree-foot cover to ward off snow and cold winds.In spring, the bunchy growing pattern of grassesprovide areas of concealment as well as bare areaswhere birds can dust themselves and move aboutmore freely in search of food. Meadowlarks,bobolinks, nighthawks, and grasshopper sparrowsfeed on insects and keep insect populations incheck. Above, larger birds such as red-tailedhawks, northern harriers, and American kestrelssurvey the open prairie landscape, looking fortheir prey. Where a wetland is nearby, gartersnakes and bull snakes hunt for frogs, mice, andother small animals. Chorus frogs and Americantoads feed on numerous insects. An occasional boxturtle may make its burrow in a sand prairie.Skinks move quickly through grasses of dryprairies.

Insects are very important to prairies. Not only dothey pollinate flowers, but they are also the basisfor many prairie food chains. Prairie mammals,birds, reptiles, and amphibians all feed onabundant insects. Countless multitudes of antsaerate and mix the rich prairie soil. Insects arethe center of life on the prairie.

As vast prairies were converted to farms, towns,and roads, some wildlife species vanished fromIowa. Iowa’s remaining prairie wildlife areconfined to small prairie remnants and restoredprairie areas. Plants and animalsthat require rare or veryspecific prairie conditionsoften are missing from theseprairie pieces. Wildlifespecies with general needsadapted to life in roadditches, pastures, andother areas of humandevelopment.



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Wetland and waterway communities

Wood ducks

Wetlands are placeswith standing wateror saturated soils

where plants and animals live.They sometimes are calledswamps, sloughs, potholes,marshes, bogs, fens, seeps, oxbows, shallow ponds,or wet meadows. Each of these wetland types hasunique characteristics. Iowa’s wetland marsheswere most common in north and central Iowa, inthe area known as the Des Moines Lobe. Thisarea, sometimes called the “thousand-lake” regionby pioneers, was a 7.6 million-acre area of vastprairies dotted with thousands of pothole wetlands.Many were only seasonally wet.

The once numerous wetland marshes that were theresult of glaciers, are called palustrine wetlands.Other types of wetlands also exist in Iowa.Lacustrine wetlands include both open lake waterand the shallow edges of lakes. Backwaters of theMississippi River and other rivers and streamssometimes have associated riverine wetlands.Wet areas where groundwater comes to the surfaceare called seepage wetlands. Fens are seepagewetlands where alkaline water rises to the surface.Bogs are wetlands that have acidic, peat soils.

Wetlands are among the most diverse of all naturalcommunities in Iowa. Plants and animals fillevery wetland niche. Wetlands are also importantregulators of the environment, filtering sedimentand organic waste from runoff and lesseningimpacts of floods or droughts.

In a river or stream community, animals andplants make their homes in moving water.



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There is both an abundance and diversity ofwaterways in Iowa – the great Mississippi andMissouri border rivers, the flat meanderingstreams found throughout most of the state, andthe cold, clear, quick waters of northeast Iowa. Aperson travelling in Iowa is rarely more than 30minutes from a waterway. However, nearly allIowa waterways have been altered to meetdemands of agriculture, industry, anddevelopment. Many of the once vibrant waterwaycommunities have been destroyed directly orindirectly by these changes.

Wetland plantsIf a person jumped into the middle of a typicalwetland pond, she would land in open water.Submersed plants, such as sago pondweed andcoontail, would tickle her legs as she walkedthrough the pond muck toward land. Soon shewould find herself surrounded by numerousfree-floating plants, such as tiny duckweeds. Asthe water became shallow, she would need to pushaway the lily pads and other large-leafedfloating plants. A thick growth of emergentplants such as reeds and cattails would mark thebeginning of the emergent wetland community.When she broke through this dense vegetation, shewould step into a wet-meadow community ofsedges, grasses, and flowers such as smartweed,swamp milkweed, and marsh marigold. The

ground would be lumpy and difficult to walkon, and could be either wet or dry dependingon the time of year and recent rainfall.

Iowa’s slow-moving streams often contain many ofthe same plants common in marshes, ponds, andlakes. In faster-moving cold water, plants such aswatercress stay anchored in the current by“grabbing on” by their roots. Algae and mosses areperiodically torn from their homes, but quicklyrecolonize once the current slows.

White water lily is a large-leafedfloating plant found in Iowawetlands.



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Wetland animalsMany animals, from tiny “water fleas” to great blueherons, make Iowa wetlands and waterways theirhome. Water plays a critical role in the life cycle ofIowa wildlife – providing areas for breeding,raising young, gathering food, and migratory reststops. For many birds, insects, and amphibians,periods of their life cycle require wetlands orwaterways.

Beaver are typically a stream animal, but thedams they build create backwaters and shallowponds. Muskrats are also important wetlandmammals. They use a tremendous amount ofwetland plants for their food and to make theirdomed, cattail lodges. The population of muskratsoften determines the amount of open water in awetland. Other mammals, including minks,opossums, raccoons, and deer, leave their tracks inthe wet soil of the stream bank.

Birds are common in wetlands andalong waterways. Killdeer may beseen on nearly every dry sand bar.Great blue herons wade in theshallow waters and use their longbeaks to probe for frogs, fish, andother small animals. Flycatchersgobble up the tremendous numberof flying insects. Red-wingedblackbirds and bitterns find refugeand food in dense stands of reedsand cattails. Above wetland waters,a northern harrier may scout forsmall animals which make up itsprey. Kingfishers and gulls divedown to snatch fish from rivers andstreams. In winter, bald eagles arecommon along larger rivers wherethey use their sharp talons tosnatch fish.

Great blue heron



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Iowa’s pothole wetlands are part of the hugeprairie pothole region that stretches intoMinnesota, the Dakotas, and parts of Canada.This vast area of prairies and marshes hashistorically been the most important nestingground of ducks and geese in North America.Mallards, wood ducks, and blue-winged teal arecommon nesting ducks in Iowa. In addition tospring nesting areas, Iowa wetlands are situatedalong the Central Flyway and provide rest stopsfor migrating waterfowl. The Mississippi andMissouri Rivers are the most important interiorflyways for migrating waterfowl in North America.Common migrants include pintails, green-wingedteal, shovelers, lesser scaup, redheads, and ruddyducks.

Amphibians are biologically linked to water. Theirlife cycle and physical adaptations bind them to adamp existence. Many reptiles are also dependenton water. Cool water and reflected sunlight allowcold-blooded animals to easily regulate their bodytemperature by either swimming or sun bathing.More than 75 species of reptiles and amphibiansdepend on wetlands and waterways in Iowa.

Small, strange-looking creatures fillevery nook and cranny of wetlandand stream communities. In openwaters, insects such as waterboatmen and backswimmers feed onplants. Water scorpions, predaceousdiving beetles, and giant water bugsare predators that search the watersfor zooplankton, other insects, and

even tadpoles and larger crustaceans. Waterstriders and whirligig beetles skitter along thewater’s surface. Fish spiders, buoyed by theirwater-repellent hairs, can walk on water as theyscavenge and search for insect prey. The air abovethe water is also thick with insect life, asdragonflies snatch up swarms of gnats, flies, andmosquitoes.

Cool water and reflected sunlightallow cold-blooded wetlandanimals to easily regulate theirbody temperature by eitherswimming or sun bathing.



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Fishy watersWarm, shallow water, often low in oxygen and highin plant life, is typical of wetlands and most Iowastreams. Some fish are well adapted to Iowa’sbroad, shallow waters – as long as they are not toowarm or polluted. Warm, shallow wetlandsusually do not contain fish.

Bluegills and black crappies find cover and nestingstructure in weedy wetland shorelines.Largemouth bass wait among the plants for theopportunity to catch an unsuspecting frog, crayfish,or small fish. Populations of bluegills, crappies,and bass are all limited in wetlands by warm waterand low oxygen levels. Bullheads, however, areone of the most numerous wetland fish, and canlive in the warm, low-oxygen water of Iowawetlands. These smaller relatives of catfish havelong whisker-like barbels that act as antennae asthe fish search the dark wetland bottoms for plantsor animals – dead or alive. The barbelseven contain taste buds that allow thefish to taste their food before biting.

Bluegills, crappies, bass, and catfish areall considered sport fish and are highlysought by Iowa anglers. Less commonsport fish in Iowa waters includenorthern pike, walleyes, and stockedtrout, found only in cooler, clearerstreams. Native trout are rare in Iowa.Rough fish, such as small minnows,shiners, and chubs, are less sought byanglers, but are critical to the food chainsthat support larger fish. Various carpand suckers are also considered roughfish, although some may weigh morethan 80 pounds.



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A dark, quiet woodlandWoodlands are dark places. Keen eyesightis an unnecessary tool where sight islimited to the next nearby bush or tree.Woodland animals, especially mammals,have acute senses of hearing and smelling.Most are active at night, when thewoodland is especially dark and quiet.Gray foxes may listen near burrows forthe movements of undergroundchipmunks or mice. Owls sit quietly andlisten for the movements of their prey onthe forest floor. Most woodland animals“freeze” when danger approaches,instantly blending in with the thick, darkwoodland vegetation.

Woodland plants living in these dark and quietplaces have evolved strategies to take advantage ofsunlight while it is available. Each spring there isa succession of growth, beginning at the woodlandfloor and progressing to the canopy. It isa race to flower and makeseeds before the leaves ofhigher layers shade thelower layers. Wildflowersand shrubs begin toblossom and turn greenbefore the understory treesleaf out. Once the canopybecomes leafy, the searchfor sunlight becomesdifficult. Smaller treesmay bend and stretch forsunlight. Vines use treesas a trellis to climbtoward sunlight.

Adapting to Iowa’s biological communities

Bittersweet

Barred owl



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Life in the open prairiesIn contrast to woodlands,Iowa’s prairies are open,dry, and windy places.Grassland vegetationprovides cover for birdsand small animals toconceal themselves. Butlarge animals, such asbison, elk, and antelope,cannot hide in the grasses.These animals havedeveloped severalstrategies to cope with lifein the open. They are alertto approaching danger and able to outrun or defendthemselves against would-be predators. They areequipped with excellent eyesight, hearing, andsense of smell. They also live in herds, which offerprotection to young animals, allow individuals toalert each other to danger, and create confusionwhen the herd is chased and scattered.

Prairie plants need to cope with extremes of heatand cold. They grow under direct sunlight,constantly losing moisture to the sun’s heat andever-present prairie wind. Prairie plants keeptheir exposure to these elements at a minimum.Most grasses have leaves that are finely divided,vertical, and slender. Some plants roll up theirleaves, and others have fuzzy hairs that furtherprotect them from losing moisture. Plants such asprickly pear cactus and yucca are more common indesert conditions, but are also found in some Iowaprairies. These plants have sticky plant juices thatare less likely to dry out. Prairie plants make useof free prairie winds and the abundance of prairieinsects to pollinate their flowers and spread theirseeds.



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A wet way of lifeFor plants and animals living in water, gettingenough oxygen requires some ingeniousadaptations. Emergent plants rooted indeoxygenated wetland muck must get all theiroxygen through pores in their leaves and stems, or,in the case of submersed plants, directly fromoxygen dissolved in the water.

Fish and some invertebrates have gills that“breathe” dissolved oxygen from the water.Animals without gills use more unusual means forgetting oxygen. Like miniature deep sea divers,whirligig beetles and backswimmers carry abubble of air with them. Worms, leeches, and evenfrogs and salamanders can absorb dissolvedoxygen through their skin. Turtles and some otherreptiles are able to absorb oxygen whilehibernating in the wetland muck. Mammals livingin water must breathe air, but they can hold theirbreath for a long time.

Animals and plants battle a constant current asthey move or remain stationary in a swift-movingstream. Most stream animals are streamlined,helping them propel through the water with littleresistance. Smaller animals and some plants findquiet places out of the current. They crawl orswim beneath or behind rocks, dig under sediment,

or find refugein small eddiesand pools.Plants, such aswatercress,stay anchoredin the fastcurrent by“grabbing on”to small rockswith theirroots.

Animals and plants battle a constantcurrent as they move or remainstationary in a swift-movingstream.



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Eventually all plants and animals in acommunity die, return to the soils,and refuel food chains.

The web of lifeIn a healthy community, there are enough foodsources, predators, and space to keep populationsof plants and animals healthy. Plants are theprimary producers of food that fuels food chains.Grasses and leaves fuel land food chains, and algaeis the most important primary producer of food inthe water. Mice, rabbits, insects, turtles, and otherwildlife feed on the plants and then become food forother animals. Predators such as shrews, spiders,turtles, and snakes feed on this prey, and may inturn also become prey. Cougars, wolves, and bearsonce sat atop Iowa food chains, but these largepredators no longer live in Iowa. Naturalpredators now atop the food chain include coyotes,owls, hawks, and an occasional bobcat or badger.Without a proper balance of predator and preyspecies, overpopulation and overcrowding can lead

to starvation and disease epidemicsamong wildlife populations.

Eventually all plants and animals in a communitydie, and it is the role of various plants and animals,such as scavenging insects and fungi, to helpdecompose and return these organisms to the soil,refueling the food chains. Food chains combine tomake an intricate food web. Within the dynamicfood web, animals are provided with a variety offood choices, including foods to fall back on in timesof emergency. The web creates health and stabilitywithin each community.

Plants are the primary producers offood that fuels food chains. Plantsare eaten by animals that, in turn,may be eaten by other animals.



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In less than a century of settlement, most ofIowa’s natural communities vanished.Prairies, largely ignored by early pioneer

farmers, were later found to providethe most fertile agricultural land,and have been impacted the most.By 1900, the Iowa prairie wasessentially gone. Scientists estimatethat no more than 30,000 acres ofprairie exist in Iowa, much of whichis tucked away along railroadrights-of-way, in old cemeteries andprairie pastures, in road ditches,around a few remaining potholewetlands, and on the slopes of theLoess Hills in western Iowa.

In a hundred-year period, from 1850to 1950, approximately 95 percent of

Iowa’s wetlands were destroyed and converted tofarmland, roads, and towns. Palustrine wetlandswere impacted the most. Only about one percentof the once abundant prairie marshes remainstoday. Channelization took curves out of riversand erased bordering wetlands. Tiling removedwater from wetlands and revealed fertile croplandsoils.

Iowans have selectively saved more woodlandsthan prairies or wetlands. Approximately 28percent of Iowa’s original forest cover remains.But these forests are often fractured into smallpieces, split by roads, farms, and towns. And Iowaforests are usually affected by human activity.Although some types of wildlife thrive in thisfragmented woodland environment, many do not.

Native prairie plants can sometimesbe found growing in Iowa roadsides.During the past 15 years, prairieroadside management has resulted inan increase in prairie plants alongIowa highways.

Protecting the pieces



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Dams along rivers and streamscreate habitat for lake wildlife, butmay act as barriers to migrating fishand create reservoirs that collectsilt. When a waterway ischannelized, many miles of streammay be lost. Less than half theoriginal inland waterways are left.Destruction of adjacent wetlandshas also played a part in alteringriver habitat, by speeding theremoval of water from the land andquickening the current of the rivers.A loss of plants bordering a streamleads to warmer, shallower waters,as shading trees and shrubs are removed and thewater is exposed to the sun’s heat and evaporation.At the same time, sediment and chemicals from theeroding land has a direct route into the waterway.

Preserving the piecesIowa’s remaining natural communities rest largelyin the hands of private landowners. Only about10 percent of Iowa’s remaining forests and prairies,and up to 90 percent of our prairie marshes, lie inthe public domain. These public lands add up toabout two percent of the total land area of Iowa.

People need to recognize the value of woodlands,prairies, wetlands, and waterway communities,and protect the small pieces that remain. Whereasthese areas are valuable for wildlife, they alsoprovide recreation and economic benefits forpeople. The vast root systems of prairie plants areresponsible for creating Iowa’s fertile soils – thebasis of our economy. Wetlands provide free watertreatment services – filtering sediment andchemicals from runoff that would otherwise enter astream or lake. Wetlands and woodlandsbordering streams help control erosion. Sawmills,veneer mills, pulp mills, pallet plants, and

When soil erodes from the land andinto a waterway, it creates sedimentpollution.



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Hunters, anglers, canoeists, trailwalkers, nature photographers, andothers make biological communitiesthe source of their recreation.

millwork operations supply jobs provided bywoodlands. According to the Iowa Society ofAmerican Foresters, Iowa’s forests contribute morethan $800 million each year to the state’seconomy.

Wild plants and animals continue to be sources ofmedicines, foods, materials, and recreation.Hunters, anglers, canoeists, trail walkers, naturephotographers, and others make biologicalcommunities the source of their recreation.

Iowans realize the special value of naturalcommunities, and many are working to rebuildnatural habitat throughout the state. It is notpossible to restore the vast biological communitiesthat once existed in Iowa, but it is possible to re-

create places for some nativeplants, provide habitat for Iowawildlife, and restore and maintainthe fertility and health of naturalcommunities, at least on a smallscale. Concerned groups andindividuals are rebuilding habitatin Iowa – by planting trees andgrasses, restoring wetlands, andprotecting remaining naturalareas.

Managing the piecesBiological communities are special and need to becarefully managed in ways consistent with theirnatural features. Modern prairie managementtechniques imitate the natural role of fire andgrazing bison to maintaining the prairieenvironment. Forest management varies greatlydepending on the goals of the land manager, butfocuses on selective thinning or clear cuts,replanting, and care and protection of trees.Water quality protection and erosion control arekey to managing wetlands and waterways.



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Iowa was once a land of vast prairies andabundant wetlands. Rivers meanderedthroughout the state and were bordered by

lush woodlands. Iowa has lost more than 70percent of its woodlands, 95-99 percent of itswetlands, and nearly all its prairies. Most of theonce wild, meandering rivers and streams are nolonger wild. The loss of natural communities is aloss of history, aesthetics, wildlife, resources, andenvironment. Iowa still has some spectacularnatural areas, but they are few and may take effortto find.

Each of Iowa’s biological communities contains aspecial mix of plants and animals that make up thenature of Iowa. Vast prairies, thick woodlands,vibrant wetlands, and meandering streams areIowa’s natural heritage.

Biological communities affect human communities.Our remaining natural areas preserve wildlifediversity, reduceerosion and waterpollution, and providerecreation andeconomic benefit.People need tocarefully manage andprotect the state’swoodlands, wetlands,prairies, andwaterways to ensurethat these specialbiologicalcommunities remainas an important partof life in Iowa.

Summing it up



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Useful resources

The Audubon Society Nature Guides – Wetlands; 1987.A Country So Full of Game; James J. Dinsmore; University of Iowa Press, Iowa City, Iowa;

1994.Extinction: The Causes and Consequences of the Disappearance of Species; Paul and

Anne Ehrlich; Random House, New York, NY; 1981.The Field Guide to Wildlife Habitats of the Eastern U.S.; Janine M. Benyus; 1989.“The Forest Resources in Iowa in 1980”; Proceedings of the Iowa Academy of Science

(88(1):2-6); 1981.Forest Statistics for Iowa, 1990; Gary J. Brand and John T. Walkowiak;

United States Department of Agriculture, St. Paul, MN; 1991.IAN Booklet Series; Iowa Association of Naturalists; ISU Extension Service, Ames, IA.

See list of titles and ordering information on page 25 of this booklet.“Iowa Natural Heritage Preservation...”; Proceedings of the Iowa Academy of Science

(88(1):43-47); 1981.“Iowa’s Forest Area in 1832”; Proceedings of the Iowa Academy of Science (94(4):116-120);

1987.“Iowa’s Natural Heritage”; Iowa Academy of Science and Iowa Natural Heritage Foundation;

1982.Iowa's Waters and Fishes: A Century and a Half of Change; Proc. Iowa Accad. Sci.;

88(1):17-23; 1981.“Iowa’s Wetlands”; Richard Bishop; Proceedings of the Iowa Academy of Science (88(1):11-16);

1981.Landforms of Iowa; Jean Prior; University of Iowa press; Iowa City, IA; 1991Living on the Edge: Endangered Species in Iowa; Daryll Howell and Mark Leoschke;

Iowa Department of Natural Resources, Des Moines, IA; 1992.Natural Resource Conservation: An Ecological Approach; Oliver S. Owen;

Macmillan Publishing Co., New York, NY; 1980.Prairies, Forests, and Wetlands: The Restoration of Natural Landscape Communities

In Iowa; Janette R. Thompson; University of Iowa Press, Iowa City, IA; 1992.Saving Soil and Wildlife: The Promise of the Farm Act’s Conservation Title;

Ann Robinson; Izaak Walton League of America; 1987.Up on The River; John Madson; 1985.Wetlands: Losses in the U.S. 1780s to 1980s; U.S. Dept. of Interior, Fish and Wildlife

Service, 1990.Wetlands Overview: Federal and State Policies, Legislation, and Programs;

U.S. General Accounting Office; 1991.Where the Sky Began; John Madson; Houghton Mifflin Company, Boston, MA; 1982.Why Preserve Natural Variety?; Bryan G. Norton; Princeton University Press,

Princeton, NJ; 1987.

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