iowa association of naturalists€¦ · iowa association of naturalists iowa woodlands 6 plants of...

Iowa Woodlands

Iowa's Biological Communities Series

Iowa Association of Naturalists

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 Woodlands is one in a series of five booklets that are part of the Iowa'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 Woodlands

1

Iowa WoodlandsWhat are woodlands?

A woodland, or forest, can be defined as a biological community of plants and animals dominated by trees. In this

booklet, the words “woodland” and “forest” areused interchangeably.

Iowa was once a land covered by vast prairiegrasslands and open savannahs. Thick woodlandsbordered the many rivers and streams, andcovered much of northeast Iowa. Wetlands dottedboth the prairie and woodland landscape. A widevariety of wildlife lived in Iowa's prairies,woodlands, and wetlands.

But the landscape of Iowa has undergone a lot ofchange in the past 150 years. Iowa's prairies,woodlands, and wetlands have all been greatlyreduced, and largely replaced by farms, towns, androads. But woodlands are by far the most commonof Iowa's remaining biological communities.

Iowa's woodlands were historically found in areassheltered from direct sunshine and strong winds,where more moisture was available. In theseareas, trees could establish themselves and out-compete the grasses that covered most of the state.Iowa rivers and streams were bordered by a thickcorridor of woodlands. The eastern, southern, andespecially the northeastern parts of Iowa weremore heavily forested than the rest of the state.Today's woodlands are fewer, but they still favorthe same climate and maintain the same generaldistribution.


Iowa Woodlands

2

The understory is thesmaller trees beneaththe canopy.

The canopy is the greenceiling of the forest.

Shrubsandvines

The floor is covered with low-growingplants and decomposing matter.

The basementcontains manytunnels andburrows, and avariety of soillife.

The forest hotelAn Iowa woodland is like a multi-level

hotel. Beneath the woodland floor is thebasement containing tunnels and burrows

that are home to a variety of unique animals.The woodland floor may be covered by mosses,

fungi, and low-growing wildflowers. The nextlevel of the “forest hotel” may consist of a thickgrowth of shrubs and vines. Smaller trees makeup the understory layer of the hotel, and thepenthouse suite is the high canopy of tall treeswhich forms the green ceiling of the woodland.Each of these layers supports a variety of wildlife,dependent on woodland plants. Each spring, thewoodland appears to come to life one layer at atime, as lower levels of the forest hotel become

green and bloom before the higher levelsleaf out and block out sunlight.


Iowa Woodlands

3

The changing woodland

Woodlands are a dynamic biological community. Awoodland may begin as a grassland, a pasture, orsome parcel of disturbed land. A few shrubs andgrassland-adapted trees begin to grow in the area.Soon the land is covered by a thick woodlandgrowth of shrubs and fast-growing trees that isdifficult to walk through. The climax vegetation,or old-growth, for a typical Iowa woodland hasvery large, leafy trees that shade out much of thewoodland floor. In these climax forests, the shrublayer is less dense and open enough to walkthrough. The floor is covered by a thick, spongylayer of dead leaves and fallen trees.

This process of change in vegetation over time iscommonly referred to as succession, and issomewhat predictable. Each stage of successionprovides a different type of wildlife habitat. Insome cases, people may manipulate a woodland toselect for a stage of succession which providesthe most habitat for certain types of wildlife.Succession in a woodland may be interrupted manytimes by disturbances such as fire, clear-cutting,wind storms, disease epidemics, or humanwoodland management techniques. Thesedisturbances may set the process back to an earlierstage or start the process over again.


Iowa Woodlands

4

Types of forests

Individual woodland areas may have differentcharacteristics depending on factors of climate andtopography. Upland woodlands are found onhilltops and on drier south and west slopes. Mostupland woodlands are characterized by a climaxcanopy of oaks and hickories – trees which arebetter adapted to sunnier and drier conditions.

Upland woodlands are currently Iowa's mostcommon type of forest. This may change however.Oaks and hickories grow to be large, leafy treesthat shade out much of the forest floor. Oak andhickory seedlings, which need to grow in directsunlight, find it difficult to grow in these shadedconditions. In some areas, shade-tolerant sugarmaples and basswoods take over areas previouslycovered by oaks and hickories.

Many of Iowa's woodlands can be found in ravinebottoms, along streams, and on the more dampnorth and east sides of slopes. These bottomlandwoodlands are usually thick with moistvegetation and provide homes for a variety ofwildlife. Ravine bottoms and stream channelsare often characterized by a climax canopy ofcottonwood, silver maple, and green ash trees, with

Upland woodlands, oftendominated by oak and hickoryor sugar maples, are a differenttype of plant community thanthatof bottomland woodlands whichoften are dominated by cottonwoodand silver maple.

The largest tree in Iowa is aneastern cottonwood. It has a trunkcircumference of more than 31 feet,is more than 92 feet tall, and has acrown spread of nearly 100 feet.


Iowa Woodlands

5

Bur oak,with its deeptap root, isthe mostcommon treeof Iowasavannahs.

basswoods growing on hillside slopes and willowsbordering the stream banks.

Savannahs are areas composed of a mixtureof woodland and grassland vegetation. Themost common savannah tree is the bur oakwhich has a deep tap root and thick bark,well-adapted to surviving hot prairie fires.

Iowa woodlands act as a transition, from thenorthern forests of Minnesota andWisconsin to the warmer, wetterwoodlands of Missouri. Iowawoodlands are often the southern-mostor northern-most range boundaries ofplants and animals that have historicallybeen rare in Iowa.

The heavily wooded area of northeast Iowa,commonly called the Driftless Area, iscovered with a variety of trees, includingnative red cedar, white pine, balsam fir, andprostrate juniper – evergreens that were morecommon to Minnesota and Canada, but were rarelynativein the rest of Iowa. The area has deep,narrow valleys, jagged hills, and deeply-cut streambeds, untouched by recent glaciers. A very rare andunique type of habitat is found in thesewoodlands. Ice caves and cold air slopes are rarehabitat for the Iowa Pleistocene snail and themonkshood flower.

Iowa Pleistocene snail


Iowa Woodlands

6

Plants of Iowa woodlands

A large variety of trees, shrubs, vines, and flowers may be found growing in Iowa woodlands. Many of these plants may

be characterized by growing in either upland orbottomland woodlands, although the transitionfrom one to the other is not always clear and mayoverlap.

Canopy TreesThe canopy trees of Iowa's upland woodlands arelarge, leafy trees which produce an abundance ofnuts. Examples are white and red oaks, hickories,and walnuts. These big trees produce a lot of foodfor wildlife, and are often preferred in woodlandmanagement for wildlife, as well as for harvestinglumber.

White oak is one of our largest canopy trees.It is very common, especially in areas that are

not very wet. The leaves are five to nine incheslong and about half as wide. They have from five tonine lobes, usually seven, and the lobes are smoothand rounded. Red oaks differ by having pointedlobes. Oaks produce an abundance of acorns andare valuable both for wildlife and as a lumber tree.

Shagbark hickory is easily identified by its loose,shaggy bark. The leaves are 8 to 14 inches longand are divided into five to seven, usually five,leaflets. The round, edible nuts are one to twoinches in diameter and have a green husk whichdivides into four sections at maturity. The nutshells are four-ridged and an off-white color. Thetrees prefer well-drained soils, but can grow in avariety of conditions. Hickory wood is valued forits strength.

White oak

Shagbark hickory


Iowa Woodlands

7

Black walnut is our most valuable timber tree.The wood is a rich, dark brown color and is highlysought as veneer by furniture manufacturers.Black walnut grows in rich soils and may be foundin both upland and bottomland woodlands. Theleaves are 12 to 24 inches long and are divided intonumerous leaflets, each about three inches long.There is a terminal leaflet which is oftenmissing. In summer the nut is covered by agreenish-yellow husk and is approximatelytwo to three inches in diameter. The huskquickly rots and by fall may be black. Thehard nut shell has many grooves and isapproximately one to two inches in diameter.

The canopy trees of Iowa's bottomlandwoodlands are also large, leafy trees. Manyproduce seeds which can be transported by water orwind. Examples are cottonwoods, maples,and green ash.

Cottonwood is a large tree found along rivers,lakes, and wetlands. The leaves are triangularand are three to five inches long. The leaf petiolesare flattened, causing the leaf to tremble in thewind. The seed capsules are borne on long catkinsand produce many tiny, cottony seeds that aretransported by the wind.

Silver maple is a climax canopy tree found inravine bottoms along rivers and streams. Theleaves of the silver maple have five lobes and thelobe sinuses are pointed or slightly rounded. Theleaves are green above and silvery below, and inautumn become a bright yellow with tints of orangeand red. The seeds are borne on wings that arelonger(1.5-2.5 inches) than those of other maples.Silver maple wood is used in cabinets, flooring,railroad ties, crates, and a variety of othermanufactured items. Sap from these trees canbe used to make syrup, but do not have as higha sugar content as some other maples.

Black walnut

Silver maple

Eastern cottonwood


Iowa Woodlands

8

Black willows prefer rich, moist soils alongfloodplains. They are the largest of the willows,sometimes growing to a height of 80 feet. Willowsare easy to identify by their long narrow leaveswith long tapering tips. The leaves of blackwillows are from three to six inches long and up toone-half inch wide. Willows have soft and weakwood, lacking durability and rarely usedcommercially.

Understory treesGrowing beneath the canopy trees, or dominating anon-climax woodland, are a variety of smallertrees. Most understory trees are shade-tolerantand grow under the partial shade of larger trees oralong the woodland edge. Examples are ironwoods,choke cherries, mulberries, and red cedars. Thesetrees provide an abundance of berries and fruit.

Ironwood, also called Americanhop hornbeam, gets its namefrom the quality of its wood.The strong, tough, durablewood is used for making fenceposts, tool handles, and otheritems which require strengthand durability. Ironwoodleaves are double-toothed andfrom three to five inches long.The seeds are borne on drooping clusters of smallpapery sacks.

Choke cherry is a small understory tree thatgrows to a height of 20 feet. The leaves are oval

to lance-shaped, sharply toothed andhairless. They range from two to fiveinches in length. The bark is gray-brownand smooth. Choke cherry fruits areedible and have a bittersweet taste. Thepurple berries are used in pies and jellies.

Black willow

Ironwood

Choke cherry


Iowa Woodlands

9

White pine

Evergreens in IowaIowa's trees are mostly deciduous. The leaveschange colors and fall off as autumn arrives. Fewtypes of evergreen trees grow naturally in Iowa.Northeast Iowa contains more types of nativeevergreens, including white pine, red cedar,prostrate juniper and balsam fir, than other partsof the state. People have planted a variety of pinesand spruces in wildlife areas, parks, windbreaks,and as ornamentals throughout the state.

White pine is easily distinguished fromother pines by its long, soft, flexibleneedles. The green needles are oftentinted with blue and are arranged inbundles of 5. The cones are narrowlycylindrical, from 4 to 8 inches, andslightly curved. The wood is popularfor general construction work, interiorfinishes, cabinets, and other uses.White pine is Iowa's only native pine.

Red cedar is a non-cone-bearing evergreen nativeto Iowa. The dark bluish-green leaves of red cedarare usually scale-like and blunt tipped. Youngertrees may have leaves that are awl-shaped andsomewhat sharp. Although not a true berry, redcedar fruits appear as light blue berries and areedible. They grow to be a medium-sized tree andcan be found in a variety of habitats, preferringopen woodlands and meadows.

Red cedar

The oldest tree in Iowais a red cedar growingin Palisades-KeplerState Park. It is morethan 475 years old.


Iowa Woodlands

10

Shrubs and vinesMost Iowa woodlands contain a thick growth ofshrubs and vines. They are a reminder that few ofIowa's forests sustain a climax vegetation. Theyare also a reminder that many of our woodlandswere at one time pastured. Thorny bushes andother plants not eaten by cattle are common inIowa woodlands. Examples are shrubs such asgooseberries, raspberries, honey locust, hawthorn,and prickly ash. Sumacs, which grow along thewoodland edge, take on a fiery red or purple colorin the fall. Many vines are found climbing on treesand shrubs and on the woodland floor. Virginiacreeper and wild grape are common vines of Iowawoodlands. A woodland vine which we should allbe aware of is poison ivy. It is very common,especially in our floodplain forests.

Gooseberry is a thorny shrub. The one- tofour-inch leaves have rounded lobes and looksomewhat like a goose's foot. The berries aregreen, changing to purple. The green berriesare sour but become less sour as they turnpurple. Gooseberries provide thorny cover forwildlife such as mice, rabbits, and songbirds,and provide food for both animals and people.

Virginia creeper is acommon vine that can climb20 feet or more using numeroustendrils that end in littleadhesive disks. It is sometimescalled five-finger, or five-leaf, ivybecause each leaf is divided intofive leaflets. The leaves are greenthroughout the summer, but inearly fall they change to a beautifulred or purple color. Occasionally acouple of leaflets may fall off, causingVirginia creeper to be confused withanother common vine called poisonivy.

Gooseberry

Virginia creeper


Iowa Woodlands

11

Poison ivy is a vine that may take the form ofa bush or small tree. Leaves are dividedinto three leaflets and grow alternatelyup the stem. The plant is sometimesconfused with young boxelder plants,which also have three leaflets but growopposite along the stem. It is a plant thatshould be avoided but need not be feared.Most people are allergic to the oil which is producedon the leaves and stems of poison ivy. The poisoncan cause rashes and blisters, and may be painful.The reaction usually does not occur until at least 12to 24 hours after contact with the plant, and cannormally be avoided by washing with warm soapywater. Poison ivy is not a danger to wildlife and isa source of food for birds that eat its berries. Poisonoak is similar to poison ivy but does not grow inIowa.

Woodland wildflowersEarly in spring, Iowa woodlands come to life assmall patches of color poke up through the litter ofdead leaves and fallen twigs. These first flowers ofearly spring, called ephemerals, are some of themost beautiful of the woodland flowers. From thissmall beginning a progression of bloomingwildflowers begins. In a woodland, springwildflowers are the most numerous and mostcolorful. Ephemerals such as bloodroot, hepatica,and Dutchman's breeches bloom before the bigtrees form their thick canopy that shades thewoodland floor. These flowers are followed bymany others including May apple, Virginiawaterleaf, and columbine. To find out more aboutIowa's beautiful woodland wildflowers, check afield guide or refer to “Wildflowers of Iowa” bySylvan Runkel and Alvin Bull. A few commonwoodland wildflowers are described on thefollowing page.

Poison ivy

Contrary to popular belief, poisonoak does not grow in Iowa. Mostsymptoms diagnosed as due topoison oak are actually caused bypoison ivy.


Iowa Woodlands

12

Bloodroot is a low-growingwildflower that is easily identified byhaving one broad, basal leaf whichwraps around the flower's stem. Theflower is white with many petals.Bloodroot gets its name from a red liquidin the plant's root. When broken, theliquid oozes out and has the appearance ofblood. Although poisonous if swallowed,the root has been used as facial paint and as a dye.

Dutchman's breeches is easy to identify. As itsname implies, individual blossoms resemble a pairof pants or “breeches,” hanging upside down from aslender flower stalk. The breeches are white andsometimes tinged with pink, and are attached tothe flower stalk at the crotch by a delicate flowerstem. The leaves are frilly or fern-like and growunderneath the arching flower stalk. Squirrel cornis very similar in appearance to Dutchman'sbreeches. Both flowers are closely related to thegarden flower, bleeding heart.

Virginia waterleaf is a common wildflower ofmoist, shady woodlands. Clusters of purplish orwhite flowers make the plant very visible from lateMay to late June or early July. Five stamensprotrude from each blossom and give the flower a“hairy” appearance. The leaves are broadlytriangular and may be doubly lobed. The surface ofthe leaves are often marked with spots thatresemble water droplet stains.

Columbine grows throughout the state and isespecially common on woodland slopes. Bright redflowers are divided into 5 tubes or compartmentswith long stamens hanging down from the center ofthe flower. Only hummingbirds, moths, andbutterflies are able to reach into the flowercompartments to drink the nectar and pollinate theflower. The plant may resemble a small shrubgrowing to two feet or more with the flowersdangling from the tips of the stems.

Bloodroot

Dutchman’sbreeches

Columbine

Virginiawaterleaf


Iowa Woodlands

13

Although trees may identify a woodland at a glance, woodland animals are just as integral a part of a woodland. A grove of

trees by itself does not make a woodland. In awoodland, plants and animals interact to make anatural community that is stable, diverse, andwondrous. Animals depend on woodland plantsand can often be found using specific layers in thewoodland.

Animals of the canopyFrom the high canopy of an Iowa woodland, a fewof Iowa's most fascinating birds may search thelandscape for their food. Hawks may use the hightreetops for nesting or perching, and hunt as theysoar above the woodland edges. Within thewoodland, owls perch or nest in the canopy as theylisten quietly in the still night for the movementsof their prey. The woodland canopy is not acrowded place, but it is a place to look for theselarge birds of prey.

Animals of the understoryThe understory mayappear to be a circus actof flying songbirds,leaping squirrels, andclimbing woodpeckers.Large leafy squirrel nestsand woodpecker holesoften can be found in

standing dead trees. In summer and early fall, thewoodland understory contains a variety of fruitsand seeds which attract a variety of birds.

Animals of Iowa woodlands

Screech owl


Iowa Woodlands

14

Animals of shrub layerFor much of the summer, woodland shrubsare the grocery store of an Iowa woodland.A variety of small birds dart in and out of the

shrubs, eating berries and insects, and takingadvantage of thick shrub cover. Deer browse onleaves in the shrub layer, while well-protectedamong thickets. A variety of insects, caterpillars,and other small creatures can be seen on theleavesof shrubs and vines. Among the blossoms ofshrubs and wildflowers, bees, butterflies, andhummingbirds search for nectar.

Animals of the floorMany animals are foundscouting around on thewoodland floor. Chipmunksand mice scurry among therocks and logs in search offallen nuts, seeds, and berries.Toads stay in the moistwoodland floor, searching forcrickets and other crawling or low-flying insects.Snakes and gray foxes hunt for the smalleranimals that seek concealment among thelow-growing plants. Raccoons and skunks prowlfor small mammals, invertebrates, and fallen nuts,seeds, and berries.

Animals of the basementThe strange world of the woodlandbasement is home to a variety ofobscure invertebrates. These animals mayhave no eyes or many eyes, a hundred legs or nolegs, antennae, hairs, slime, or any combination ofcharacteristics. Termites, isopods, larval insects,and a host of other small invertebrates arecommon residents in the woodland basement.Tunnels crisscross under the ground and revealthe movements of moles.

Eastern mole

Graycatbird

American toad


Iowa Woodlands

15

Plants and animals relate to each other inmany ways to form a healthy woodlandcommunity. The variety of relationships

among plants and animals makes woodlands verycomplicated, yet stable. People need to understandthese relationships before they can understandhow a woodland community works.

Hide and seekThe dense vegetation of an Iowa woodland makesit ideal for animals trying to conceal themselvesfrom predators or for predators trying to sneak upon prey. The majority of woodland animals take onthe colors of their surroundings and may havespots or stripes which further aid in theircamouflage. Although moths and butterflies mightbe brightly colored, their caterpillars usually blendin with the leaves on which they feed. Mostwoodland animals have evolved a strategy of“freezing” when danger approaches. Deer, rabbits,chipmunks, and toads are very difficult to seewhen they remain still.An exception to the “hide andseek” strategy is the stripedskunk. The skunk's blackand white colors form awarning colorationthat is easy to see andquickly tellsapproaching animalsto stay away.

Woodland ecology


Iowa Woodlands

16

A dark, quiet woodlandWoodlands are quiet and dark places. Keeneyesight is an unnecessary tool where sight islimited to the next shrub, often less than two feetaway. Woodland animals, especially mammals,have evolved acute senses of smell and hearing.Most are active at night when the woodland isespecially dark and quiet. A raccoon prowls alongrivers with its nose close to the ground. Gray foxesmay listen near burrows for the movements ofunderground chipmunks or mice. Owls sit quietlyand listen for the movements of their prey on theforest floor.

The search for sunlightIowa's deciduous forests are thick and shadyduring the summer months, but more open inearly spring. Woodland plants have evolvedstrategies to take advantage of sunlight.Each spring, there is a succession ofgrowth, beginning at thewoodland floor andprogressing to the canopy.It is a race to flower andmake seeds before theleaves of higher layersshade the lower layers.In early spring mossesbecome bright green.Wildflowers and shrubs begin toblossom and turn green beforethe understory trees leaf out.

The tall canopy trees are thelast to sprout leaves. Once thecanopy becomes leafy, thesearch for sunlight becomesdifficult. Smaller trees maybend and stretch for sunlight.Vines use trees as a trellis toclimb toward sunlight.

Barred owl


Iowa Woodlands

17

Predators, prey, and population controlIn a healthy woodland community there areenough predators, food, and space to keeppopulations of plants and animals healthy.Green woodland plants are the primaryproducers of the food that fuels woodlandfood chains. Leaves, fruits, nuts,berries, and wood provide food for avariety of animals. Mice, rabbits,chipmunks, insects, deer, and otherwildlife feed on woodland vegetationand then become food (prey) forother animals. Predators such asshrews, spiders, raccoons, opossums,and snakes feed on this prey and mayin turn become prey for largerpredators.

Cougars, wolves, and bears once sat on topof woodland food chains, but these largepredators no longer live in Iowa. Predators whichremain atop the food chain include great-hornedowls, red-tailed hawks, and a few bobcats.

People have assumed the role of large predatorsthrough wildlife management practices thatinclude hunting seasons to control preypopulations of animals such as white-taileddeer, raccoons, rabbits, and turkeys. Withouta proper balance of predator and prey species,overpopulation and overcrowding can lead tostarvation and disease epidemics.

Eventually all plants and animals in a woodlanddie, and it is the role of various plants and animalsto return these organisms to the soil and refuel thefood chains. Termites, slugs, and fungi may be asimportant to a woodland community as deer,raccoons and owls. A variety of food chainscombine to make an intricate food web. Thestrands of this web create health and stabilitywithin woodland communities.


Iowa Woodlands

18

People and woodlands

In addition to their intrinsic value, woodlandshave cultural, economic, and recreationalbenefits for people.

A cultural resourceBeautiful woodlands, vast prairies, dynamicwetlands, and meandering rivers are all part ofour Iowa heritage. When we lose these naturalareas, we lose part of ourselves. We may forgetthat the land has made us what we are. When welose woodlands, our feel for Iowa history is lost. Itbecomes difficult to picture life in a woodlandsettlement. The materials, foods, medicines,pleasures, and fears of our past are buried withthe trees, shrubs, and wildlife of our woodlands.

People have historically used woodlandplants and animals for food, medicines,materials, and clothing. American

Indians and European settlersquickly learned special uses for a variety

of plant and animal species. Furs fromwoodland mammals such as deer, beaver, andraccoons were once very important as sources ofclothing. Woodland animals provided meat forthe table. Woodland fruits and vegetables wereused in American Indian and pioneer medicines.

Trees were especially important to early settlersas they built cabins and farms. Wood was used to

make furniture, wagons, and barrels, andburned for fuel. Some areas of the state

were heavily logged to producerailroad ties.


Iowa Woodlands

19

Economic considerationsWoodlands provide direct benefits to our economy.Sawmills, veneer mills, pulp mills, pallet plants,and millwork operations provideIowans with jobs and help feed theIowa economy. More than 12,000Iowans are employed in the woodindustry. According to the Iowa Societyof American Foresters, Iowa forest'scontribute more than $800 million eachyear to the state's economy.

Wild plants and animals continue to besources of many medicines, foods, and materials.Researchers use wild plants as a resource to createbetter, more disease-resistant crops, and look to adiverse pool of plant and animal species to findcures for diseases such as cancer, heart disease,and other illnesses. Perhaps a rare woodland snailwill prove to hold a cure that saves human lives.Trees and other plants can also help Iowans savemoney and conserve energy by sheltering homesfrom cold winter winds and the hot summer sun.

Woodland recreationWoodland areas are a money-making attraction inIowa. Forested watersheds slow the flow of waterto our streams and help maintain cleaner, clearerwaterways. Woodlands provide homes for avariety of wildlife. Beautiful waterways and avariety of plants and animalsmake Iowa's woodlands afavorite source of recreationfor many people. Whenvisitors use Iowa's beautifulwild habitats for hunting,fishing, hiking, birdwatching, nature enjoyment,or other activities, they bringmoney into our state.

Iowa Forests contributemore than $800 millionto the state’s economyannually.


Iowa Woodlands

20

People and woodlands

When European settlers first arrived inwhat is now Iowa, approximately sevenmillion acres of woodlands bordered

the many rivers and streams and covered the hillsof northeast Iowa. But Iowa's forests were thefirst type of habitat to be impacted by Europeansettlers. Farms and towns soon spread amongIowa's woodlands and waterways, and Iowa'sforests were quickly cleared for agricultural land.

Most settlers, who had their roots in the woodedeastern states or in Europe, did not feel comfort-able on the open prairies. There was also a biasfor woodland soils. The pioneers believed that soil“too poor to grow trees” was not fit to producecrops. Had they known that the world's mostfertile soils lay under the open grasslands, itwould have made little difference. There were nodevices which the pioneer farmer could use to plowthrough the thick prairie sod.

The period of early settlement had a severe impacton Iowa's forests. During the period between1832 and 1875, Iowa's forests decreased fromapproximately 7 million acres to approximately 2.1million acres.


Iowa Woodlands

21

Approximately 28 percent ofIowa's original forest coverremains. But these forests areoften fractured, split by roads,farms, and towns. And Iowaforests are usually affected byhuman activity. Althoughsome types of wildlife thrivein this fragmented woodlandenvironment, many do not.

Iowans realize that they have lostsomething special in woodlandhabitat. Concerned groups andindividuals, trying to bring backthese special areas, are rebuildinghabitat in Iowa. Anyone can plant trees at aminimal cost. Landowners can plant trees andreap benefits in timber sales. Schools can planttrees and be rewarded with an outdoor classroom.By planting trees and creating a woodland in whatwas once a developed area, communities receive aplace for beauty, solitude, wildlife, and recreation.

Private and public woodlandsApproximately 90 percent of Iowa's remainingwoodland habitat lies in the hands of privatelandowners. Some natural areas have remainedin the hands of private ownership for hundredsof years, maintained through generations ofenlightened people who have a strong appreciationfor the land. Since so little of Iowa's land is inpublic ownership, the decisions of privatelandowners are critical to maintaining wildhabitat.

Landowners reap benefits from a woodland. Theymay manage a forest for wildlife and to harvestlumber or fuel wood. They may hunt, hike, fish,pick mushrooms, and otherwise enjoy the habitatthey are protecting.

Only about 10 percent of Iowaforests lie in the public domain.


Iowa Woodlands

22

Approximately 10 percent of Iowa's remainingforests lie in the public domain. Whereas theseareas are valuable for wildlife, they may also bemanaged to provide certain types of recreation forpeople. Public natural areas are often classified asa preserve, refuge or sanctuary, wildlife area, orpark, depending on how the land will be used bypeople.

Management techniquesPrivate landowners or public agencies manageforests using a variety of techniques, depending onthe desired outcome.

Timber Stand Improvement (TSI) is a commonwoodland management program which usesseveral management practices, including woodlandprotection, selective tree cutting and planting,thinning of overcrowded areas, and improving theeconomic value of specific trees. TSI may be usedto speed tree growth, improve wildlife habitat,grow firewood, and make money for thelandowner.

Often, woodland managers use TSI techniques toenhance the growth of nut-producing species suchas walnuts, oaks, and hickories. These specieshave both economic and wildlife habitat value.The growth of these trees is enhanced by openingup sections of the woodland to sunlight. Old andundesired trees are cut and seedlings or nuts areplanted in the resulting open forest floor. Manytree species, including oaks and hickories, areshade intolerant and will not grow well in theshade of larger trees. Some old or dead trees areleft to provide homes for wildlife.

Good woodland management must include theirprotection. Woodlands are protected byeliminating grazing, and controlling fire, insects,diseases, and other destructive agents.


Iowa Woodlands

23

It is important to remember that woodlands maybe managed for a variety of reasons. In somecases, a landowner may do nothing more thanprotect a woodland and let nature take its course.Landowners should consult a professional foresterregarding a management plan for their forests.In the right column is a list of district forestersemployed by the Iowa Department of NaturalResources.

Iowa’s state forestsIowa’s state forest system is comprised of fourmajor and six minor forests totaling more than40,000 acres. The larger forests are: Stephens,Yellow River, Shimek, and Loess Hills. The sixsmaller state forests are: Backbone, White PineHollow, Holst, Pilot Mound, Barkley, and Gifford.State forests are managed by professionalforesters in the Iowa Department of NaturalResources’ Forests and Prairies Division.

Iowa’s state forests provide a variety of goods andservices. State forests are managed to provideclean air and water, wildlife habitat, lumber andother forest products, and recreationalopportunities. The forests also provide protectionof Iowa’s endangered and threatened plants andanimals, and opportunities for education andresearch.

Best management practices (BMP)are in place on all state forest land inan effort to protect watersheds andwater quality. A Best ManagementPractices manual can be obtained bywriting or calling the IowaDepartment of Natural Resources (seepage 24).

Offices of Iowa Department ofNatural Resources District Foresters

District 1: Elkader319-245-1891

District 2: Charles City641-228-6611

District 3, Marshalltown641-752-3352

District 4, Anamosa319-462-2768

District 5, Wapello319-523-8319

District 6, Fairfield641-472-2370

District 7, Chariton641-774-8733

District 8: Adel515-993-4133

District 9: Oakland712-482-6245

District 10: Lemars712-546-5161

District 11: Creston641-782-6761

District 12: Webster City515-832-3585

District 13, Iowa City319-351-8886

Iowa’s State Forests


Iowa Woodlands

24

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 State University Extension publications; contact your county extension office.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.Wildflowers of Iowa Woodlands; Sylvan Runkel and Alvin Bull; Iowa State University Press,

Ames, IA; 1979.Why Preserve Natural Variety?; Bryan G. Norton; Princeton University Press,

Princeton, NJ; 1987.

Useful resources

iowa association of naturalists€¦ · iowa association of naturalists iowa woodlands 6 plants of...

Documents