Introduction and Description of the Wetland Ecosystem

THE WETLANDS OF DANE COUNTY, WISCONSIN

Prepared by

Barbara L. Bedford Elizabeth H. Zimmerman James H. Zimmerman

for the

Dane County Regional Planning Commission in cooperation with the Wisconsin Department of Natural Resources

The preparation of this document was financially aided through a federal grant from the Department of Housing and Urban Develop- ment through the Urban Planning Assistance Program authorized by Section 701 of the Housing Act of 1954, as amended; and by funds from the Wisconsin Department of Natural Resources through the Outdoor Recreation Aids Progr'm (ORAP) and other Department of Natural Resources funds. COMMISSION Richard Pire, Chairman Merton Walter, Vice Chairman Fred Raemisch, Secretary Sanford Anderson, Treasurer Robert Ballweg Walter Bauman Carl Jensen William Lunney Marilyn Slautterback Mary Louise Symon Ole Week

STAFF Charles Montemayor, Executive Director Thomas Brant, Deputy Director C. M. Tabaka, Director of Land Use Planning Thomas Favour, Director of Transportation Planning William Lane, Director of Environmental Resources Planning Thomas Smiley, Director of Community Services Louise Smoczynski, Administrative Assistant Shirley Ruhland, Clerk Steno IV James Steffenhagen, Graphics Chief

WISCONSIN DEPARTMENT OF NATURAL RESOURCES CONTRIBUTING STAFF

Clifford L. Brynildson David A. Gjestson Ruth L. Hine Earl Loyster Allan J. Rusch Harry Stroebe, Jr. Donald R. Thompson Charles Wahtola Scientific Areas Preservation Council PREFACE

The present survey of Dane County wetlands was undertaken with several goals in mind. Existing wetland surveys, although useful in a general sense, do not provide the information and detail needed to carry out modern wetland protection policies.

A shift is being made in many states, including Wisconsin, toward inventorying with black and white, color, and various types of infrared photography from airplanes and satellites. However, this type of survey, useful as it is fox locating and delineating wetlands, requires backup studies on the ground to aid in the interpretation of vegetative cover and to add information of other types. Water quality, rare plant communities, and wildlife use fall into the category of valuable additional information. This study will hopefully aid in inventory and interpretation by indicating what information is readily obtain- able in the field.

In this survey, our emphasis has not been on identifying and delineating wetland areas in the manner of a general inventory. Instead, it has been on the wetland, surrounding upland, and watershed relationships as a unit, as is necessary for management planning. Each wetland was considered for its unique qualities. Hopefully, this approach will he found useful by the State of Wisconsin in conjunction with its planned photographic de- lineation of wetlands.

We hope that the results of the present survey will be used by all in Dane County who have responsibility or concern with the future of its wetlands. This report has been aimed at planners, policymakers, landowners, students of the wetland ecosystem, conservationists, and the interested public. It was felt necessary to give enough background material in the introduction so that those not familiar with wetland ecology could understand the descriptions and management suggestions. Although our sources of technical information were many, we were unable to cover all which might have proved to be of importance. We take full responsibility for all errors and omissions, and hope that readers will not hesitate to call them to our attention.

F'inally, the Dane County wetland survey was a pilot study on techniques of making such inventories in the future. We have learned a great deal concerning how such a survey could have been organized and carried out more efficiently, as well as some improvements in technique that could be made in the future. It is our hope that others undertaking wetland surveys, in Wisconsin and elsewhere, will benefit from studying the results of this one. If any valuable wetlands anywhere axe protected as a result of this work, we will feel our effort has been many times repayed.

iii We are grateful to the many people without whose assistance this survey would have been difficult if not impossible to carry out. Foremost among these are the present and former commissioners and the staff members of the Dane County Regional Planning Corn- mission, who showed great patience and cooperation, and whose technical assistance made it possible for this report to appear in print. Information, assistance, and advice came from many people. Both knowledge and inspiration were gained from contact with them. Much of the field work was done with the assistance and companionship of Paul Putzer, Don Samuelsen, and Robert Werner. Their contributions were basic to the completion of the work.

Clifford E. Germain, William Tans, and Robert H. Read of the Wisconsin Scientific Areas Preservation council provided information and field assistance. More importantly, they otherwise reinforced our efforts by their example, dedication, and good will. Of his storehouse of accumulated knowledge and experience, Earl Loyster of the Wisconsin Department of Natural Resources gave freely. Other members of the staff of the Department, most notably Donald R. Thompson and David Gjestson, were likewise generous in supplying information on state-owned wetlands.

Dr. Lutz Bayer assisted in the identification of certain aquatic invertebrates. Dr. Frank A. Iwen, Dr. William G. Reeder, and Richard Vogt provided information on invertebrates, amphibians, reptiles, and small mammals and supervised field shpling'of . . selected Dane County wetlands. Jeffrey Burns conducted bird surveys of selected wetland areas. Some of the last minute field checking was done by Michael John Jaeger, who also shared with us his knowledge of ephemeral ponds in north central Dane County. For calling particular wetland areas to our attention and contributing to us their own personal knowledge of them, we are grateful to Dr. Calvin B. DeWitt, Rosemary Fleming, Robert Friedman, Scott Huston, Harriet Irwin, Lu Severson, Maarit Threlfall, and Jonathan Wilde. Jerome Seljan, Carl Guell, and Molly Fifield were kind enough to make several trips into the field to assist with photographic work.

Dr. ~anielE. Willard reviewed portions of the manuscript and clarified certain ideas by refusing to accept a general statement. Dr. Gerhard B. Lee was most helpful in reviewing the section on wetland soils and making numerous suggestions. The Agricultural Stabilization and Conservation Service of the U.S.D.A. kindly lent us their aerial photographs, which we realized too late we should have purchased, and waited patiently for their return. We hope any inconvenience caused to the public will be repayed by the publication of wetland maps for their use. PART I INTRODUCTION In order to live a full and healthy life, man needs a healthy environment, Man has evolved dependent on his physical and biological world; it has shaped him both physically and psychologically. Wetlands are a basic part of this natural heritage. All life arose in the water. Shallow seas, lakes, streams, and wetlands played a vital part in evolution. Our vertebrate ancestors came onto dry land from habitats not unlike our present wetlands. We are still biologically tied to the water, as are the life forms around us.

We live in a time of greater and faster change in the environment than has ever occurred before during the existence of man. Even the glaciers did not affect so many habitats so fast, nor did they have the worldwide scope of human impact. By our numbers and sophisticated activities, we have become a geological force. According to whim, we can reroute rivers, cause deserts to bloom, render forests into desert, even redesign the topography altogether. Most of our activities have been undertaken without regard to biological results. Wetlands have suffered their share of devas- tation, through flooding, drainage, filling, and many subtler means. Until recently, little attention has been paid to their value.

At this point in time, there is a new awareness of the consequences of our activities. This comes none too soon, as our growing population and technology are causing ever more rapid and irreversible destruction of natural resources. Decisions are now being made which will affect land use for decades or centuries to come. Our success in sustaining and restoring the natural environment depends on planning, and planning depends on knowledge. A new emphasis is, therefore, being made on gathering knowledge, from detailed analysis of single species to vegetation studies from satellites. The results of these studies will be used in two ways: to make an inventory of existing natural areas and problem areas; and to understand better the physical and biological processes in the environment. Both types of knowledge are essential to planning.

VALUES OF WETLANDS

Wetlands contribute to a healthy environment in several ways. They affect the quantity and quality of water. They act to retain water during dry periods and hold it back during floods, thus keeping the water table high and relatively stable. Aquatic plants use nutrients in the water, storing it as peat after they die. Silt settles as water flow is slowed by the stems of emergent plants. Removal of wetlands causes faster runoff of dirtier water. Because they collect and hold water and other materials, their condition can be used to indicate problems on the surrounding upland. Biological benefits include feeding, breeding, and drinking areas needed by all animals, and stopping places and refuge for waterfowl (for thorough discussions of waterfowl use of Wisconsin wetlands, see Jahn and Hunt,,1964, and March et al, 1973). The presence of water is also atcractive to many upland birds and animals, During the winter, wetlands with springs provide needed open water. Due to glacial action and shapes of water- courses, wetlands often occur in groups or corridors. This arrangement is an additional attraction to wildlife, since a wetland complex provides a larger region to move about in. . . Like any other natural habitat, wetlands are important in supporting species diversity, and have a complex and important food web. In fact, it is here that the food webs of land and water are most connected. Scientific values include a record of geological and botanical events in the past, a place to study biological relationships, and a place for teaching. It is especially easy to give young people a feel for the biological world by having them study in a wetland. Other human uses include low-intensity recreation and esthetic enjoyment.

SOME PAST WETLAND STUDIES

Wetlands in southern Wisconsin have been subjected to low- key studies since the white men first appeared. The best early description of Dane County vegetation comes from the survey,of 1832-1835. Ellarson (1949) interpreted the Dane County portion of this survey. The surveyors were asked to describe vegetation as they laid out townships, ranges, and sections. Despite the variability in their knowledge of plants, a picture of the vegetation at the time of settlement does emerge. . .. . Wetlands present at that time were open marsh, low prairie, lowland hardwoods, and swamp conifers, using Fassett's (1966) categories of plant associations. In the glaciated eastern half of the county, the principal vegetation was "marsh grass, reeds, rushes, or flagsn in open marsh. These marshes run northeast-southwest due to glacier flow, while in moraines marshes are isolated kettle holes. One notes that the attitude that wetlands were useless already prevailed at the time of the survey. Surveyors found areas "not susceptible of cultivation" or which "cannot be drained so as to be of any use", Channel deepening for boat use was also of interest at that time, as noted by the remark: "The Catfish Creek [Yahara] at a moderate expense in deepening the channel may become (acd undoubtedly will) navigable for stream boats from Rock River to this lake [~endota]a distance by its meanders, of about 20 miles." However, the surveyors did note the value of marsh streams for water sources, mill- dam sites, and transportation. Some were indeed used later as millponds. An important concept here is that steep hills, streams, and marshes were considered as fire barriers. An example of this situation can be found in T7N R12E (Town of Deerfield), and T8N R12E (Town of Medina), the present Goose Lake Public Hunting Ground and the area north of it which did and still does have a large stand of tamaracks. When Ellarson helped with a Soil Conservation Service survey "to determine the feasibility of draining a portion of this area for agricultural purposes," he found that:

"the steepest portion of this lowl~nd,the first 3000 feet, was open marsh, whereas the remainder of flatter portions with poorer drainage was tamarack swamp. It would appear that tamarack swamp occurred where surface drainage was sufficiently impeded to allow an area to remain wet throughout the year. This is probably not so important as a soil-moisture factor in promoting tree growth, as it is a factor in the prevention of fire from sweeping these areas regularly." (Ellarson, 1949) In the western, non-glaciated region of the county, open marsh was limited to land adjacent to streams in valley bottoms. Low prairie was probably present also, but not mentioned, since apparently only one surveyor recognized it. One finds that although the value of preserving navigable waterways has been recognized for centuries, wetlands have not fared well in the public opinion (Scott, 1965). In 1850, Wis- consin received a "Swamp Land Grant" from the federal government. This act enabled states to reclaim the "swamp lands within their limits." When the state sold the lands it was to use the proceeds "exclusively as far as necessary, to the reclamation of said lands" (Jones, 1926). A total of 2,174,223 acres of swamp land (sic) were obtained by the state over the period 1850-1880. With present day hindsight, one finds it regrettable that the state did not designate certain of these for preservation. Now, of course, repurchase is expensive and difficult, and rehabilitation is often necessary. However, this opportunity for the state to preserve a large share of its wetlands did not come at a time when the public was ready to appreciate it. The mood was one of pioneer exploitation. By 1852, the first of a series of acts to encourage drainage had been passed. Berkley (1853) expressed the prevailing attitude of the times:

"It will not, I hope, be necessary for me to prove the injury done to agriculture by stagnant water, from whatever source the moisture arises, whether from surface water or from springs beneath the surface, the necessity still exists for its removal. No grass or grain ever grew upon a lake, submerged land will produce nothing; marshes grow grass in spite of the water dwelling upon them. I' . . .and further:

"To change a marsh from its foetid, cold and vaporous atmosphere, into a fruitful, smiling plain; to render a bog or swamp, where no sure focting can be found, into solid and substantial earth; to make aquatic plants give place to rich and feeding herbs; to render agreeable food to the animal instead of coarse wiry unpleasant grass, is the object of draining land. . ." He goes on to describe various methods:

"In springy ground which occurs in elevated as well as low land, all that is necessary is to tap the spring, put in your drain, excavate to a depth of three to five feet. . .n . . .and to provide some insight into local changes: "Two years ago it (part of the City of Madison) was so wet as to be impassable; previous to that time it was a lake of water--now it is sound, cultivatable ground."

He says, ". . .I never hesitated to drain, . .". This idea is still with us, even though we have since lost tens of thousands of acres of wetlands from Dane Cuanty alone. Several studies from the latter part of the 19th century are of interest. Chamberlin (1876-1882) published a map of native vegetation of Wisconsin and one of Dane County geology in his "Geology of Wisconsint'. He did not record shrubs and trees in the sedge meadows, but his state map (P1.IIA) was not sufficiently detailed for conclusions to be drawn. His county map (Pl. XIII) shows both the bedrock geology and the locations of wetlands, but recent work (Olcott, unpubl. map) shows a much more complicated relationship. Trelease (1089) made a study of algae and algal blooms in the Madison Lakes in the 1880's. He already saw algal blooms on Lake Mendota, but only after spells of hot calm weather, and not in all summers. Although fewer precautions were taken at that the with rural and urban runoff and sewage, the human population density was much smaller in the area than now. Blooms are now commonplace in Lake Mendota during most of the warmer part of the year. It is known that the lakes in the area were rich in nutrients before settlement, but there is insufficient knowledge to separate natural and cultural eutrophication clearly.

E. A, Birge did a study of Cladocera (water fleas) in the .Madison area during the same period. He found Lake Wingra very marshy, with abundant numbers and species of water fleas (Birge, 1892). For further detail, see "Lake Wingra Wetlands". In 1893, Cheney and True published their work on plants of the Madison area. They covered perhaps the central quarter of the county. Their plant list gives a good indication of wetland and upland conditions at the time, many of which no longer exist. They saw and described Hook Lake, the Dane County wetland which probably has changed the least, as well as a bog (now gone) which they found in the Town of Madison. --- . -. - -. -. - During the present century there has, of course, been much more work on wetlands than earlier, but not anywhere near as much as on prairie, forest, or lakes.

In 1908, Stout worked on a haymeadow where the Dane county Fairgrounds now stand (Stout, 1912). There is now no trace of the area he studied. It already belonged to the Dane County Fair Association at that time, and had been altered by the construction of a race track, as well as railroad tracks and a canal. Stout made a count of plant species and abundance in a strip four inches wide and 2300 feet long. He was interested in plant associations and in the weight various species added to the marsh hay. He also studied the environmental requirements of certain plants, and went so far as to grow them at various water depths. stout's work is discussed further elsewhere in this report.

A fascinating study by Cahn (1915) of the Wingra Springs area, now part of the university of Wisconsin Arboretum, indicates some 2f the extensive changes that have taken place. He found open 3edge meadow where trees and shrubs are now dense. Most surprisingly, to those who know the Arboretum now, is his finding that the marsh .lawk (Circus hudsonicus) was abundant, andthat the short-eared owl 'Asio flarnmeus) was common. He photographed the nests of both.

A soil survey of Dane County was published by the U. S. Iepartment of Agriculture in 1915. A portion considers the extensive peat areas of the county, their location, composition, and suitability for agriculture. Suggestions are to drain and to use conunercial fertilizer for a variety of crops. From 1927-1933, Costello did a study of sedge tussock meadows of southeastern Wisconsin. Although he remained within 35 miles of Milwaukee, the species he studied, Carex stricta, is common in Dane County. He discussed the ecology ot tussock meadows: their initiation, development, subsidence, and place in succession. He also discussed the effect of grazing, fire, and invasion by shrubs and trees (Costello, 1936) . Frolick (1941) studied the vegetation of Dane County peat lands during the 1930's. Between Stout's study and Frolick's, a considerable change took place in most of the sedge meadows of the area. The effects of drainage, grazing, mowing, and burning were common by the 193O1s, and are discussed in detail in this paper. Curtis discussed wetland vegetation in his "Vegetation of Wisconsin'' (1959), but knew it less well than he knew upland vegetation, He was not aware, for instance, of the fen of more than 80acres at Cherokee Marsh, and he thought undisturbed fen would develop into shrub-carr. He gave an overall view of the southern sedge meadow, but said little about the Carex sedges themselves. He found fire to be a control on shrubsn sedge meadows, with a return to deeper water conditions after a more severe fire. Bogs were also discussed, but primarily the northern type.

White's paper (1965) on the shrub-carrs of southeastern Wisconsin covers mostly disturbed areas. In fact, he found that only eight out of his 175 study areas had been undisturbed by man for more than twenty years. However, since all had been disturbed in the 1920's or 19301s, he could not draw any conclusions regarding lack of disturbance.

A very interesting and different approach is that of Vogl (1969) who did a study in 1966 of an area in Jefferson County that he had known over a 25-year period. The activities of man in the area since settlement are documented, along with changes in the vegetation (Fig. 4). Cause and effect can be seen clearly here. This approach is useful in that it points the direction for further study, The foregoing discussion illustrates both the sporadic nature of wetland stidies and the great range in attitude toward wetland values. The reader will find in going through this report that great holes in knowledge exist. Intelligent wetland conservation will be difficult unless they are attended to. NEED FOR mTLAND STUDIES

More recently, interest in planning for wetland preservation has increased greatly, along with increased awareness of their many values. During the last two years alone, we have become aware of planning and inventory efforts in several states. In Wisconsin, such efforts include high-altitude photography, field studies, legislative activities, and studies by regional planning commissions. The task of identification and evaluation will be long and difficult, and will involve the services of geologists, hydrologists, soils specialists, lirnnologists, biologists, game and fish managers, and serious amateurs.

THE ROLE OF THE DANE COUNTY REGIONAL PLANNING COMMISSION

In the final Land Use Plan for Dane County (DCRPC, 1973), the need for careful planning is clearly stated: "During the 1960's alone, the population of Dane County increased by more than 30 percent. . ." it points out. The result is certainly increased pressure on the land and greater conflict over its use. Since 1968, the Dane County Regional Planning Commission (DCRPC) has been accumulating information on the natural resources, since "resource analysis is a basic part of the comprehensive planning program". The need for the present study could not be better stated than in their Plan:

"In the last half century, two-thirds of the County's wetlands have been drained and are no longer available as a component part of the natural hydrologic system and wildlife habitat. Most of the drainage activity took place because it was widely believed that wetlands served no useful purpose and that the land could be more productively put to agricultural or urban use. However, it has since been recognized that wetlands, like all other parts of the natural environment, are an integral part of a complex ecological system. The essence of the concept of an ecological system is linkages: every-$hing in the system is related directly or indirectly to everything else in the system. It is impossible to alter one element without affecting the system itself and its other component parts."

The Plan proposes to preserve and restore wetlands. It calls upon the state for improved legislation to protect wetlands and scientific areas. Detailed study of wetlands, and acquisition of key areas by the state is urged, with county cooperation. THE ROLE OF THE STATE

The state also recognizes the need for wetland protection. The Natural Resources council of State ~gencies,in its 1973 publication, "Managing Wisconsin's Natural ~esources",notes that "wetland maps and inventories for-___ mag __ counties ._ _-_.are currently out of dategq. Two of its proposals are: "Establish and fund a program to update wetland maps and inventories. . ."; and "Conduct research relative to wetland values and functions that will establish more.precise criteria for decision making" with "a rating system which will reflect public values and interest in the conservation of specific wetlands." The Cepartment of Natural Re- sources (DNR) has shown a great interest in studies of this type, to aid the Scattered Wetlands Purchase Program.

DESCRIPTION OF THE PRESENT STUDY

We hope that the present study will help establish a . ,.---- , . , ,., - basis "for future wetland inventories around "the state, as well as help the Dane County Regional Planning Commission and the Department of Natural Resources in their plans for land use in Dane County. This is the first attempt to inventory such a 'large area in any but a cursory manner. In the past, studies were either detailed and local, or took in a large region superficially, often'due to lack of funds. Increased environmental concern makes the present type of study possible. Un- doubtedly, the approaches and techniques used here will have to be refined; thus, their major value may be in stirring up interest. Further, it is our aim to point out weaknesses in present unders.tanding and hopefully to stimulate further interestin research. Certainly not least, it is our desire to help educate the public as to the values of wetlands, since it is often the private landowner that holds the key to preservation. Thus, our report is aimed at the planner, the wetland manager, the future researcher, and the concerned landowner. We hope each may find something of use in this presentation. SCOPE OF THE STUDY

The scope of the present study is a detailed inventory of the wetlands of Dane County, Wisconsin. The emphasis is on biological data collected in the field. Most field work was done during 1972 and 1973, although information was drawn from previous and current studies by the authors and other workers. We hope results from future studies will be added, and necessary modifi- cations made. Minimum field information obtained includes wetland type, dominant vegetation, andwhere applicable, a vegetation map, a plant list, fauna observed, an estimate of water quality, major geologic features, acreage, ownership, upland and wetland land use at present, extent and type of water, soil, and vegetation disturbance, and existing problems. Where practicable, history of land use was correlated with its effect, and landowner attitudes were examined. Studies of water quality beyond visual estimates require chemical tests. The time and funds available for the present study did not make this possible. The purpose of the inventory was to provide information with which planning decisions could be made. A priority system was, therefore, attempted, but with the understandings that (a) any such listing or grouping is necessarily somewhat arbitrary, to the extent that all factors cannot be known nor are all wetland processes presently understood; and (b) the position of a particular wetland low on the list does not signify an endorsement that it should be altered or destroyed. Classification was made in terms of present or possible biological value, scientific value, public use, extent of degradation, and extent of immediate or long-range threats. The results are to be used (1) for planning wetland acquisition by the state and county; (2) to prevent destruction before planning can be completed; (3) to discern where possible the general effects of future loss; (4) to establish guidelines for use, management, and preservation; (5) to designate wetlands of outstanding educational and scientific value and those most suited for recreation and public use; and (6) to indicate further studies needed. Wetlands covered included all of those known or suspected at the time of the beginning of the study to be of value. The most valuable of these were studied and mapped in detail. In addition, other wetlands were studied in as much detail as practicable, given their condition and time available. In the event a given wetland had been completely destroyed, that fact was merely noted. Our working hypothesis was that the information necessary to determine the type of wetland (such as deep-water marsh, or sedge meadow), its condition (such as eutrophic, or partly drained), and its value can be read from indicators seen in the field. The more deeply one is able to go into, for instance, hydrology, water chemistry, and vegetation, the more clearly one can understand and interpret this information. To establish a basis for interpreting this work, then, it is necessary to discuss basic background information. PART II THE WETLAND ECOSYSTEM GEOLOGY AND THE FORMATION OF WETLANDS

Dane County, although a relatively small area (1,233 square dles, Cline, 1965), hae a diversified geological history. Thi~ has affected the nature and distribution of wetlands found here by the first settlers, and in turn, the number and distribution of drainage projects since undertaken. The bedrock in Dane County is sedimentary, built up over the long interval of the Cambrian and Ordovician Periods, beginning about 600 million years ago and znding about 430 million years ago, These layers re8t on very old crystalline rock, mostly rhyolite, granite, and basalt (Cline, 19 65) which does not allow much water penetration, and may be regarded as a afloor" under the water-bearing rocks (or aquifers), The sedimentary layers were laid down, hundreds of feet thick, on the bottom of a shallow sea that existed intermittently for over 200 million years. After that, the earth's crust in this area began to rise above sea level, deposition slowed, and erosion began. Since that time, erosion has worn down the surface unevenly. Now that the topmost layers of rock have been removed, their former thickness and composition in this area can never be known.

The "geologic column" gives a description of the thicknesses, compositions, and names of the rock layers, Ostrom's (1967) up-to-date version of the geologic column of the State of Wisconsin gives appropriate nomenclature. The important points are that (I) the thick lower deposit of sandstone (405-1175 feet thick) carries large quantities of ground water, and is the most important aquifer (Cline, 1965) ; and (2) above it are younger, alternating layers of sandstone and dolomitic limestone which are less often wazer saturated and tend to be less permeable. ,...... ---- -...... -. . - .,. These rocks had been well dissected by river and stream drainage of a branched pattern by the time of glaciation (Olcott, unpubl. map). The topography at that time was probably not con- ducive to wetland formation except in limited areas along stream valleys. The present Dunlap Hollow is probably much like the wetlands which existed then.

The following discussion of glaciation and its effects has been simplified to emphasize points which affect wetlands, Perhaps 70 thousand years ago there was a period during which the precipitation in northern North America was higher than usual. So much snow accumulated by winter's end in central Canada that by the end of the summer it had not all melted. Year by year it was added to and compacted into ice. The weight of the ice caused the edges to push outward, and the ice mass expanded during what is known as the Wisconsin Glaciation to cover most of Canada and . the northern part of the United States. By about 27 thousand years ago, the ice moved forward across Wisconsin. It was at least the fourth glaciation to affect southern Wisconsin. AS the glacier moved forward, it scoured the landscape smooth in some areas, carried the broken up material (drift) with it ,and deposited it farther south. It flowed over some of its own material, possibly due to unevenness of deposition or pressure, and made the smooth hills, or drumlins, that are characteristic of eastern Dane County as well as a large area to the east and north. The drumlins interrupted the shallow drainage pattern, and between them numerous extensive wetlands formed after the glacier was gone. A portion of the Green Bay Lobe advanced to its maximum extent about 18,000-20,000 years ago along a line from Prairie du Sac through Cross Plains and Verona to just east of Belleville. West of this line is the "Driftless Area," now thought to have been covered by a glacier much earlier.

As the recent glacier advanced across Wisconsin, ice also was being lost by melting. Finally, the rate of melting was great enough to balance influx and accumulation, and the glacier edge could advance no farther. For a period of time the edge remained in about the same position. New ice was moving toward this stationary edge, melting as it went, and carrying ground up rock with it. This material was accumulated and deposited as till (an unsorted, unlayered, ice-deposited mixture of clay, silt, sand, gravel, and boulders) at the edge as the terminal moraine. Eventually, the ice melted back, leaving the till pile behind. Buried in this were blocks of ice which slowly melted. The deposit slumped, leaving "pot" or kettle holes. Some of these kettle holes have since filled with water and formed isolated small ponds or marshes. An example of such a pothole region can be found south of Fish Lake. It is quite probable that Hook Lake is also a wetland of this type. After melting back a short distance, the'glacier edge again stopped moving, dumped more material, then continued retreating. Two parallel moraines resulted, the terminal Zohnstown and the recessional Milton. Together, these form a wide band of deposited material and kettle ponds bisecting the county.

As the glacier retreated, it dropped a sheet of material of varying thickness over most of the landscape. In the process, river valleys were blocked, and lakes and marshes were formed. Some of the shallow depressions so formed became sites for extensive, but drainable, sedge meadows and bogs. Drumlins also blocked water flow. Thus, the glacier created wetlands in several ways: partly filling bedrock valleys, by causing blockage of waterways, and by leaving chunks of melting ice buried in . till. The till itself also holds some of the ground water and, along with the bedrock, provides for underground flow between adjacent wetland basins. The sizes, shapes, and distribution of wetlands is thus arfected by geologic history. Cline (1965, P1. 2) shows Dane County divided into five regions according to topography and glacial deposits. We use these regions in the present report for grouping wetlands by location (see Fig. 1). The wetland communities mentioned here are discussed under "Ecological Concepts". 16

1. "Wisconsin River Valley". This region is dominated by floodplain topography, with the county's only sizeable floodplain forest on alluvial deposits. The flat topography and slow drainage.causes wetlands such as sedge meadows to occur a short distance from the river'e edge.

2. "Valley and Ridge". This is the stream valley topography typical of erosion of bedrock, and is the part of the "Driftless Area" which extends into Dane County. The stream valley wetlands here are of the same form as eleewhere along the southern part of the Wisconsin River watershed. However, there has apparently not been enough soil disturbance due to alluvial deposit along these small watersheds to allow the seeding in of floodplain forests. Small deposits are found along the stream banks with sedge meadows and shallow marshes a short distance from the stream. These wetland areas are necessarily narrow and restricted to the flatter locations in their watersheds.

3. "Moraine". A broad strip of terminal and recessional moraine deposit characterizes this region. The thickness of sandy and gravelly material varies considerably so that much of the terrain is filled with small steep hills and kettle holes. Wetlands here tend to be small, isolated, and often steep-sided. Often they occur in groups with gravelly deposits between them.

4. "Yahara River Valley". Glacial deposit filled old stream valleys in this region. Drainage has been slowed and re- routed, but has re-established the same general pattern as before. Valley floors became very much flatter, water was spread out and flowed slowly. This led to the formation of the large peat deposits which are typical of the Yahara watershed. Wetlands here tend to be large, interconnected, and surrounded by low hills. In most cases, aquifers in the bedrock of the hills provide spring or discharge areas (see "Wetland Hydrologyw), which help peat formation by keeping it waterlogged.

5. "Drumlin and Marsh". This is similar to the above except that glacial deposit filled flatter watersheds in the smaller streams. Wetlands are of the same character and very interconnected. A field of northeast-southwest oriented drumlins separate wetlands into parallel lobes. The topography is low and rolling, and has lent itself to extensive drainage. Cline (1965, P1. 2) shows the undrained condition. Old wetland areas, formed by sedge meadow, fen, or bog, can still be located by the presence of peat deposits. A few isolated remnants in fair condition still exist. Many other remnants are ditched, nearly drained, and full of nuisance plants such as nettle, giant ragweed, and reed canary grass. WETLAND SOILS

Wetland soils, with the exception of alluvial or streamflow deposits, form on waterlogged or inundated depressions or flats. They may also form on seepage slopes and near springs where the soil remains saturated for long periods or continuously. Wet- land soils range from mineral soils (sand, silt, or clay) with a high organic content to peat and muck, which are entirely or almost entirely organic. The storage of organic material occurs because waterlogging prevents the access of oxygen and the break- down of plant parts and animal remains. The activity of micro- organisms is inhibited. Wetland mineral soils, those with a lower organic content than peat or muck, nevertheless contain more organic matter than upland soils. In the spring, especially in eastern Dane County where many shallow wetlands have been drained, the dark wetland soils are prominent in plowed fields, contrasting with the lighter, grayish-brown upland soils. These wet mineral soils have very drab gray subsoil layers, frequently with rust and gray mottles. Peat, defined by Whitson (1927) to contain 50% or more of organic material, is also abundant in Dane County. Peat has a high carbon and nitrogen content, but phosphorus and potassiurh con- tents are low, and these must be added in cultivation. Soil scientists now have available a new classification system (Soil Survey Staff, 1974) based on quantitative criteria and criteria which can be determined by simple field tests. A discussion of the classification of predominantly organic soils, now called Histosols, is found in Histosols: Their characteristics, classification, and use (Aandahl, et al., eds., 1974). Histosols are divided into three kinds: Fibrists, Hemists, and Saprists. Fibrists are the least decomposed, and still contain the fibrous remains of rushes, cattails, sedges, and other plants which grew in the wetlands as much as hundreds or thousands of years ago. Hemists are partly decomposed by oxidation and Saprists the most decomposed. Saprists, also commonly called muck (G.B. Lee, pers. cornm.; Davis and Lucas, 1959, In Phillips, 1970), are granular and no longer show identifiable plant remains. Along with the storage of plant parts, animal remains, and organic compounds, there is the storage of an historical record. The technique of pollen analysis, the measurement of plant genus or species abundance from pollen from various carbon-dated peat layers, has become a valuable tool for the study of post-glacial climate and vegetation. In general, the climate and vegetation of the uplands have been studied, while the history of the peat formation itself has often been neglected. Certainly no detailed record exists for Dane County. A typical core may be as follows. Under the organic deposit one would find a layer of gravel, sand, silt, or clay, representing glacial deposit. Over this would be a grayish white layer of limy material, or marl, representing the bed of a post-glacial lake. Calcium carbonate (lime) is removed from the water by certain plant species, notably algae of the genus Chara, and deposited on the bottom. Snail and clam shells are characteristically present. Other organic material in this layer is derived from algae, aquatic invertebrates, and submerged and floating aquatic macrophytes (large plants, excluding algae). This is referred to in general as limnic (lake) material, and may form a layer over a foot thick. Above the limnic material is a layer of peat, which may be anywhere from several inches to well over 30 feet thick, depending on the shape of the wetland basin, climate, and hydrology. Characteristically, the lower or older layers of peat are formed by deep water emergent plants such as bulrushes and cattails. As the thickness of peat is built up, vegetation characteristic of shallower wetlands moves in, making a layer of sedge peat. In northern bogs, and in certain southern Wisconsin wetlands, vegetation invades the lake basin by forming a floating mat. In this case, there may be little or no cattail and bulrush below the sedge layer, or they may be mixed. Depending on local conditions, shrubs, trees, or Sphagnum moss may finally invade. In Dane County, the only extensive, actively developing Sphagnum moss peat is found in Hook Lake, Layers of woody and mossy material can be recognized in peat deposits, and probably are common in the county. After the peat has filled the lake basin to the level of the water table, it becomes dry enough on the surface to support a surface fire during a drought. After wetter weather returns, restoring the usual water table, the burned down surface of the peat is wet enough to support shallow marsh plants. These build up the peat again to a drier surface which supports sedge meadow plants. Such burn cycles leave charcoal layers in the peat. Presumably, whether or not fire occurs, peat accumulation slows down as the level of the water table is reached. To a limited extent the peat may inhibit water flow enough to raise the water table, but eventually must reach a point when the oxidation and deposition rates are about equal. If the water table is then artificially lowered by drainage, oxygen can enter the soil, causing oxidation and increasing the activity of bacteria and invertebrates. This results in the decomposition of the peat. Further, once peat dries out its structure changes and it may not be possible for it to become waterlogged again. Drained, oxidizing, and drying peat deposits are common in Dane County. Fire is a very rapid oxidation. Oxygen is combined with the carbon in the peat, and carbon dioxide and heat are released. Some of the other elements in the peat are left behind as ash. An increase in ash concentration may also result from deposition of material from surrounding uplands or from slow oxidation of organic material at the surface (Frazier and Lee, 19711. It is thought that cellulose in the plant remains is decomposed more rapidly than lignins, and this results in a layer of increased carbon concentration (Frazier and Lee, 1971). Thus, by studying chemical composition, pollen, spores, and other identifiable organism parts, and gross structure of the peat, and dating the whole, one can begin to understand the formation and history of deposits. Peat deposits do not build up rapidly, and rates are variable. After more than 14,000 years, the peat deposit in South Waubesa Marsh has built to a maximum known depth of over 90 feet (DeWitt, pers. comrn., from a study by Friedman). Since peat deposition is controlled by the shape of the basin and by the water table, the upper surface is nearly flat and the edge deposits are shallow. This marsh contains drier regions where there is probably no net deposition because of surface oxidation. On the other hand, these are still deeper and wetter areas where peat deposition may have been set back by fire or where water flow may be removing organic material. Not all of Dane County's wetlands contain advanced peat deposits. The marshy bay of Fish Lake appears to be only ten feet deep at the deepest point in years of average rainfall. Much of the organic deposit in the bay is unconsolidated, and has not reached the water surface even along the shallow edges. It is possible that some of the material is carried to the deeper part of the lake. The depth of the sediment there is not known to us, but cannot be great, since the lake is still about 60 feet deep (Poff and Threinen, 1961). The Fish Lake marsh is a typical deep marsh. When the emergent vegetation dies, some material sinks to the bottom and some remains floating on the surface. Presumably the latter is eventually oxidized, since it disappears and the lake has no outlet. Some of the live plant material is eaten by muskrats, pulled up and left floating, or made into muskrat houses. These houses slowly decay and may sink to the bottom or remain floating for a long period. The relationships between peat and vegetation have been studied in this region by only a few (Costello, 1936; Wilde and Randall, 1951; Catenhusen, 1950; Frolik, 1941). This is an important avenue of research. As yet, most workers have only considered the effects of peat conditions and manipulation on vegetation. Very little beyond classification has been done on the effect of vegetation on peat and peat formation. Costello's discussion of sedge tussocks does cover this to a limited extent. The sedge Carex stricta propagates by putting out rhizomes, or specialized, root-like stems. These grow horizontally a few feet, then the tips turn upward to start new plants. A new plant soon forms a tussock or stool. A network of roots, dead leaves, and other debris remains and the plant continues to grow upward on it. The tussock, which may extend a foot above the ground, is an adaptation for a fluctuating water table. 'The plant does not drown in deep water in the spring nor dry out in late summer, due to its tussock and deep roots; some part of the root system usually gets both air and water (Costello, 1936). Tussocks also contribute somewhat to peat formation, but not as much as the remains of plants in more evenly waterlogged situations. Peat formation in colder, wetter situations in Europe and Asia has been studied, since bogs are extensive there. However, no literature on this subject applicable to Dane County was found. The alkaline sedgy peat (fen) deposits of this area are not well understood. It is essential to control wetland loas so such basic processes can be adequately studied.

Until recent years, studies of peat in this country have mainly been in regard to its agricultural uses. General descriptions, classifications, and examination of chemical content have been helpful for this, but have aided neither the understanding nor the preservation of wetlands, Some recent studies have emphasized the effects of undisturbed and of drained peat cle- posits on water quality. This extremely important field is just beginning to be explored. Since settlement and the beginning of large-scale agriculture, erosion from uplands has greatly increased, to about 3 tons per acre per year on 5% slopes (Muckenhirn, pers. corn.). In wetlands bordering cultivated fields, sediment from erosion loss is often carried out a limited distance onto the peat surface. Plant indicators of such soil disturbance are often found along the edges of Dane County wetlands. (The use of plants as indicators is discussed under "Ecological Conceptsn.) Where highway or housing developments have caused extensive deposition of topsoil and subsoil in adjacent wetlands, surface soil characteristics have completely changed from organic to inorganic. It is not unusual in heavily developed areas to see cattails growing out of such deposits. The stands on the north side of Dunn's Marsh make an excellent example (Pl. 1). Of course, if this rate of deposition is allowed to continue, wetlands will fill up rapidly.

Readers wishing a more detailed discussion, including wetland soil chemistry, are referred to Phillips (1970). WETLAND HYDROLOGY

HYDROLOGIC CYCLE AND WETLANDS

The hydrologic cycle describes the passage of water from the atmosphere to the land, lakes, and oceans, and back tgthe atmosphere. Wetlands are a valuable part OF this cycle. Water en7 tering wetlands may come as rain falling directly on them, as overland runoff, or as flow emerging from underground. This water collects in basins and in regions with slow drainage. It may remain in stagnant pools, flow through the wetlands in surface channels, or seep slowly through the soil. Evaporation and overland flow are the major means in our region by which water leaves wetlands. For wetland vegetation to thrive, water must stand or flow slowly just below, at, or above the soil surface for at least several months of the year. In turn, the existence of wetlands modifies the flow and evaporation of water, Therefore, it is helpful to consider the interaction of surface water, ground water, and wetlands,

SURFACE WATER In Wisconsin's moderately humid climate, rates of annual precipitation onto and evaporation from the surface of a body of water balance on the average. However, these rates fluctuate with storm cycles, the seasons, and longer term fluctuations in local climate. During drought, those wetlands fed primarily by overland runoff tend to dry up. Many shallow wetlands of this type are now ditched and used for cultivation. Since the topography of the surrounding region is generally not altered, the natural flow patterns remain and successful cultivation is very dependent on annual and seasonal rainfall. During periods of heavy rainfall, wetlands serve as buffer zones against flood damage. A large volume of water can be held in a shallow natural basin, without undue damage to the wetland community, thus protecting communities downstream. The Town of Lodi, in Columbia County, was protected in this manner in 1965. Overland runoff is a natural process which in itself is not harmful to wetlands. However, it always involves some erosion, since the surface of the land is not indestructable. Runoff only becomes a threat when the rate of erosion and the consequent depositional load become large, as is often the case in a man-influenced watershed. We consider the runoff and erosion processes briefly here. PLATE 1 SILTED CATTAIL STAND

PLATE 2 ALGAL BLOOM

PLATE 3 * - -= ---- 5 -. 1 CROSS SECTION OF CATTAIL. I SHOWING AIR SPACES 4

Natural erosion occurs very slowly in our climate due to .the vegetation cover on the land. Soil is continuously recreated by the breaking up of parent rock materials and the addition of organic matter. If erosion occurs at the same rate or more slowly than soil formation, there is no net soil loss. When vegetation is removed, the soil is exposed to the action of water, and erosion accelerates. In an experiment, it was found that the erosion that would occur under corn in 50 years would take 15,000 years under fallow land; 27,400 years under forest; and 171,500 years under grasslands (Bennett, In Fournier, 1972) . The first rain that falls on bare dry soil soaks into it until it is damp. Then the energy of the falling rain tears apart groups of soil particles and a mixture of soil and water is scattered on the surface. These smaller particles are light enough to be carried away by the runoff. Of course, a downpour on a steep slope of fine soil will carry away particles faster than will a light rain on a gentle slope where soil particles are heavy. If there had been vegetation here instead of bare soil, it would have taken up some of the energy of the falling rain. Water dripping off the plant leaves would have done less damage to the soil structure. Organic matter and roots also help to hold the soil together.

When the soil can no longer absorb water, either because it is saturated or because the rain is falling faster than it can sink in, runoff begins. Streams of runoff water break up the soil further and carry particles along. These moving particles in turn add to the erosive power of the running water, just as sand-blasting wears away the surface of building stone. Gullies are often formed. On the other hand, grass lies flat and protects the soil from running water (Fournier, 1972). The finest material is carried the farthest; such silt deposits are commo'n in Dane County wetlands. The above effects are enhanced when the soil is bare in the early, spring. The weather is warm enough to permit rain, but no water can penetrate the frozen soil. Surface material is softened and removed. Materials such as manure are easily carried off the land at this time. We have often seen dirty water. on top of ice in wetlands in late winter.

Urban runoff presents a different picture. Although water falling on roofs and pavement carries very little in the way of soil particles away with it, other problems arise. Less of it can sink into the ground to recharge the ground water, although how much less is still a matter of debate. (See discussion of the Wingra springs in "Lake Wingra Wetlands".) Even rain falling on lawns probably does not sink in as rapidly as otherwise because the soil is often accidentally or even purposely packed down. The result is a high rate of runoff from the land, with abnormally large and zapid water level fluctuations in wetlands and lakes. Water quality is affected also. Runoff carries salt, sand, and petroleum products off the roads overland or down storm sewers into wetlands and lakes. Two fairly recent examples are (1) a flow of tarry paving material from a shopping center through a storm sewer into Dunn's Marsh at Madison, and (2) an oil spill near Lake Ripley in Jefferson County. Both were fortunately contained. Various nutrients are carried from the city down the watershed and add to eutrophication problems. (See "Nutrients and Water Quality".) Minerals are leached out of lawn fertilizers and leaves piled in or near gutters, for example. Minerals leached out of forest leaves enter the soil, but leachate from gutters is fed directly down storm sewers into lakes and rivers. Further, gullying below storm sewer outfalls can be a large contributor to siltation in wetlands, as seen in the UW Arboretum and Eagle Heights.

GROUND WATER Ground water is extremely important to wetlands. Almost all of Dane County's wetlands depend on a ground water supply for their existence. Ground water refers to a region where pores, cracks, and cavities in and between rocks and soil particles are saturated with water. The upper surface of the saturated zone is referred to as the water table. This surface rises and falls as the ground water is replenished or removed. The ground water flows slowly from regions where it is recharged (added to from above the surface of the ground) to where it is discharged (flows out onto the surface). In Dane County, as in the rest of the Midwest, recharge is subject to an annual cycle. In early spring when snow melts and rains occur frequently, most of the year's recharge occurs. As the weather becomes warmer and plants become active, evaporation and transpiration (water movement from the soil through plants into the atmosphere) occur at rapid rates. Not much, if any, water passes through the soil to add to the ground water. During wet years such as August 1972-May 1973, considerable recharge may occur, as evidenced by high discharge rates noted in this study throughout 1973. Conversely, during drought the water table is lower due to lower recharge rates, and discharge rates also drop.

AS Madison expands, more large wells are drilled, and pumpage increases; cones of depression ('see Fig. 2) in the ground water are appearing, enlarging, and coalescing. These cones are temporary in the sense that if pumpage stopped they would dis- appear. However, a conflict may emerge between use of ground water for the city supplies and for the protection of discharge into wetlands. FIGURE 2 THE EFFECT OF PUMPAGE ON WETLAND SPRING FLOW

c(p,1tn " BE~~~EPL.

LOSS OF SPRING FLOW

PROPORTIONS ALTERED FOR PURPOSES OF ILLUSTRATION

SOME RECHARGE AND DISCHARGE RELATIONSHIPS IN DANE COUNTY

RECHARGE ?

J/&@ J/&@ .., . ..

-:;:. . .' 'd WETLANDS 'SCHARGE VERTICAL SCALE IS EXAGGERATED. TOTAL HARDNESS FIGURES ARE FIRST APPROXIMATIONS. Overland runoff has always contributed an additional water supply, although originally a minor. -. . one. Since settlement, two major changes have occurred. Extensive drainage programs have led to efficient drawing off of this discharge water from many wetlands, leaving them drying and deteriorating. Since the ground water supply is still present, a reversal of the drainage conditions could lead to rehabilitation. Second, although water entering from surface runoff is often still a minor contributor to the volume of water in the wetlands, it is of deteriorating quality. Especially in smaller wetlands receiving urban runoff or water from large surface watersheds, there is now enough contribution to cause sudden and large fluctuations in water level. There is still debate on questions as to whether accelerated runoff affects ground water recharge adversely, whether bare soil is less useful for recharge than vegetated soil, and whether extensive roofing and paving in urban areas cuts down on recharge rates. Olcott (pers. corn.) believes that runoff has not adversely affected recharge areas in Dane County. It is our feeling, however, that if rainwater runs rapidly off of slopes or down city storm sewers before much recharge can take place, there must be a compensating decrease in the recharge rate. Whether or not it affects the water table enough to cut down significantly on discharge into wetlands is not clear.

INTERACTIONS OF WETLANDS AND GROUND WATER The interaction of wetlands with ground water is extremely important. If the water table is low, the wetland tends to dry up slowly. This may come about in one of four general situations: (1) The wetland is "perched", or above the water table but its basin floor is sealed by a layer of impermeable clay. In this case, there can be no direct linkage between the wetland and the water table, but both are responding to a period of drought. Water evaporates both from the upland soil surface and from the wetland surface during hot dry weather and is not replaced by rainfall. During a period of high rainfall, the wetland and ground water are separately replenished. Probably few of Dane County's wetlands fall into this category, but Hook Lake may (see Fig. 3).

(2) The wetland is a recharge area, that is, an area where water moves from the surface into an aquifer. An aquifer is essentially a rock formation that contains and transmits water. It must run in coarse, gravelly or sandy materialorthrough rock fractures or solution cavities or porous rock. In other words, the water must be able to movethrough the subsurface material for an aquifer to exist. In the Dane County area, glacial deposits, limestone, and especially sandstone all have possibilities for conducting round water. If the water table is high, or if water reaches de recharge area by rainfall or overland flow faster than it sinks in, a temporary wetland may exist there. This typically occurs in early spring. On the other hand, during drought or periods of high evaporation such as summer, the aquifer is not replenished as fast, the water table drops below the surface, and the wetland dries up. Wetlands such as these make up an insignificant portion of Dane County's recharge areas, but may be important in the spring for wildlife. Even if they are lost as wetland communities, recharge will continue since it depends on physical conditions. (3) The wetland is either a recharge or a discharge area, depending on temporary rainfall and evaporation conditions, and is filled with water because its basin extends below and communicates with the water table (Fig.4). Even in this case, the levels of water in the wetland and in the ground do not usually rise and fall together. After a hard rain, especially if overland flow occurs, the level will be higher in the wetland. If there is no clay seal in its basin, water will percolate from it into the ground until both levels are about the same. After a drought, the water level is down in the wetland due to evaporation, but may be replenished somewhat by ground water. Eventually, however, the ground water may become low enough so the wetland dries up. Peat marshes, by contrast, store water so well that they may remain somewhat moist even when the ground water has dropped several feet lower (Irwin, 1973). his might be due to the formation of a seal under the peat, or to the character of the peat itself. (4) The wetland is a discharge area, as is usually the case inDane County (Fig.3). Although such a wetland may receive water from overland tlow, its distinguishing feature is the presence of springs and seepages. Dane County has several such wetlands of considerable size and esthetic quality. Seepages in this region tend to be alkaline, hence there are many fens.(See discussion of communities in"Ecologica1 Concepts".) After aperiod of rainfall, flow from springs increases and remains high for an interval of weeks or months. After a drought, the reverse occurs. Since ground water moves slowly, about 5 feet per day (Kazmann, 1965), these effects occur much more gradually than surface changes. Water levels controlled by ground water tend to be relatively stable and changes are gradual. Work at the South Waubesa Wetlands indeed showed stable spring flow (DeWitt, pers. comm, ) . Many life forms require this situation. Again, drying up of surface conditions goes along with a slow lowering of the water table and a depletion of aquifers, and the wetland eventually dries up. We were unable to find literature on springs which would be useful for further discussion.

A somewhat different type of discharge situation exists in the stream valleys in and near the "valley and ridge" region, including Fisher Valley (Story Creek). The water table tends to be higher along the sides of tile valley floor than near the stream. The sources of groundwater include all of the surrounding hills, as well as local percolation of surface water. This ground water then enters the stream along its length, but except during rainy periods, the stream surface is below the surrounding water table. The layers of alluvial deposit on the valley floor tend to retard flow and maintain this situation. Thus sedge meadows are typically found a short distance from the stream edge and above its level (see Fig. 5).

For a diagrammatic review of the effects of land use on wetland hydrology, see Figure 6, FIGURE 4 A POSSIBLE WETLAND - GROUNDWATER RELATIONSHIP

VERTICAL SCALE IS EXAGGERATED

FIGURE 5 STREAM BANK RELATIONSHIP

SEDGES, HIGH WATER TABLE BERM OR NATURAL STREAM BANK (DRIER) /

VAL LE FLOOR

WATER TABLE FIGURE 6

HYDROLOGY AND WETLAND HULTH 15-2al 33" ANNUAL NAP. PREC IP. (SLOPES EXAGGERATED)

UNDER NATURAL FOREST OR PRAIRIE. HILLS STORE WATER FOR STEADY CLEAN FLOW INTO PERCOLATION ' @ WETLANDS, STREAMS AND LAKES ABOUT 4" DEEP-PERCOLAT ION (HOSTLY FALL C SPRING) RECHARGES GROUNDWATER

SEIALL GRADUAL ------_

SOIL AND ROCK SERVE AS SPONGE AND FlLTER OF

CAN NOT STOP

BY ACCELERATfNG RUNOFF, AGRICULTURE AND URBANIZATION CHANGES INPUT INTO EXTREME HIGHS AND LOWS OF DIRTY UATER. SUDDEN FLASH FLOODS CARRY @ SOIL AND FIR7 ILIZLR AND RAISE WATER LEVELS; BETWEEN RAINS, INPUT IS LITTLE OR NONE, ALLOWING WATER TO DRY UP OR AT LEAST CONCENTRATING FERTILIZERS.

------__---_ EARLY FALL LOU/------,

SOFT MUDDY BOTTOM

BI G-CITY URBANIZATION LlKE MADISON IS FURTHER LOWERING WATER TABLE BY HEAVY PUMPING (ESPECIALLY HEAVY IN SUHKER WHEN WETLANOS NEED SPRING FLOW HOST). HYDROLOGISTS SAY: @ WITHOUT RESTORING GRWNOWATER AND/OR REDUCING DEMAND AND SPACING WELLS FARTHER APART, MDISON'S PROJECTED GROWTH TO YEAR 2000 WILL ELlHlNATE MOST OF DANE COUNTY WETLANDS AND CAUSE tAKE AND STREAM DETERIORATION. NUTRIENTS AND WATER QUALITY

EUTROPHICATION

Eutrophication is a term which describes the addition of nutrients to aquatic ecosystems, along with its physical and biological results. This is a process which occurs naturally to a greater or lesser extent, depending on the local availability of nutrients, the rate at which they enter the system, and the rate at which they leave. Lakes or marshes, including their bottom sediments where nutrients are stored, and their watersheds, must be considered as systems. This relationship explains the need to control or at least direct man's activities in an entire watershed in order to preserve the quality of a marsh or lake. The extent of possible natural eutrophication of a lake or marsh is probably limited by its environment. If it receives ground water seepage, it may even revert to less fertile conditions (Hutchinson, 1969). The process Hutchinson may be referring to is that the nitrogen from ground water is stored in the peat, and thus is not all available for cycling. On the other hand, phosphorus binds to soil particles in the upland (Biggar and Corey, 1969). and does not enter the ground water in quantity. This makes land use control and protection of ground water recharge and discharge (springs and seepage) very important.

To understand why eutrophication is undesirable, it is necessary to realize that (1) it produces undesirable effects, such as unpleasant algal blooms (Pl. 2) , dense growths of waterweed, and often the deterioration of fisheries; and (2) cultural, or man-caused, eutrophication proceeds much faster than--perhaps more than 100 times as fast as--the natural process. Further, the addition of nutrients is often accompanied by addition of toxic chemicals or silt. As the bottom is built up by either silt or organic material, it may become warmer causing chemical reactions to speed up. Nutrients become more available, and the process accelerates.

NUTRIENTS

A discussion of the nutrients, their availability, and the level of understanding of their role in the ecosystem will be helpful. The elements which are the most important in the biological cycle are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur. Their compounds are the principal building blocks of living tissue. Along with these are a large number of lesser- used elements, such as sodium, potassium, calcium, manganese, and many others. The most important nutrients in this discussion are nitrogen and phosphorus. Nitrogen can enter the biological system in many ways. It is the most abundant element in the atmosphere, and can be carried by rainwater or "fixedn by certain organisms. "Fixing" involves making the nitrogen into compounds that organisms can use, and is done in aquatic ecosystems by blue-green algae and some bacteria. Nitrogen from upland plants and animals, and their wastes and debris, is carried by runoff into aquatic systems. To these and other less important sources, cultural ones are now added. Fertilizers and agricultural and urban wastes are the most important of these.

The aquatic ecosystem loses available nitrogen by outflow, by storage, and by some deqitrif,ication. Outflow may be overland or through ground water recharge. Storage is by sedimentation, and is not necessarily permanent. In wktlands in particular, the thick peat layer represents nutrient storage. ~atesand controlling factors for exchange of nitrogen with sediments are still poorly understood. For further details of the cycle, see Fig. 7.

Phosphorus is available from rocks and soil. Some may be brought in as wind-blown dust. Waste and detritus from upland organisms are important sources. Major cultural sources are agricultural fertilizers and phosphate detergents, but other sources such as municipal and industrial wastes are also important. In agricultural practices, nutrients are removed from the soil via harvesting of crops, meat, and animal products. In order to replace the phosphorus, commercially produced phosphates from outside sources are applied to the soil. This addition of fertilizers must balance what the farmer removes in harvesting and what is lost in runoff. The runoff, which represents additional phosphorus in the drainage basin, ends up in the lakes and marshes. The problem of municipal waste, on the other hand, is one of a concentrated source. Since Dane County is not primarily industrial, that source will not be considered further.

Phosphorus loss from the aquatic'ecosystem may be by addition to the sediments, some of which is temporary, or by harvest or runoff. Artificial dilution has been tried as a control measure where practical. Water is pumped onto the upland with the purpose of letting phosphorus be picked up by the soil as the water runs back into the lake. This has had limited success (Born et al, 1973). ~lternatively,nutrient-poor water may be added to the lake to flush it, thereby reducing the phosphorus concentration.

See Figure 8 for a diagrammatic review of the phosphorus cycle.

EFFECTS AND CONTROL OF NUTRIENTS

The mechanism for trapping phosphates on the sediments allows for their liberation just when they can most contribute to an algal bloom in progress. The bloom uses up oxygen, the bottom becomes anaerobic (without oxygen), iron compounds are reduced (lose oxygen), phosphates are liberated, and contribute to more bloom (Rohde, 1969) . FIGURE 1 NITROGEN CYCLE Input HUMAN ACTIVITY RARELY, N (WASTE, FERTILIZERS, COMPOUNDS CHEMICqLS, MARSH DRA I NAGE , ETC. )

DEC RAINFALL, FIXATION BY

WASTE FROM LAND ANIMALS, MlGRA BIRDS, ETC.

HARVEST1 NG ( WEEDS, FISH, ETC.

2 PART l CULATE , VAR 1 OUS COMPOUNDS ORGANIC SEDIMENT MOSTLY N 1 TRATES (peat)

Output & Storage FIGURE 8 THE PHOSPHORUS CYCLE

ROCK Input

UPLAND SOME AGR I CU LTLI RAL , U R LEACH l NG ' ECOSYSTEM DUSTFALL INDUSTRIAL SOURC

D1 AY, x WASTES, L RUNOFF

ALGAE C) LU CERTAIN WATERWEEDS 4 * szf 1 t a ul

I MAL

DEPOS IT !!:I,'.? HARV EST

SED lMENT Output and Storage

FIGURE9 A A POSSIBLE EUTROPHICATION PICTURE

2 N03 (atmospher lc N I TRA'TE n l t rogen) I I RUNOFF, RA-I N , CYCLING FIXING K (potass i urn) ospha tes , organ ic and I norgan lc)

ANAEROBIC CONDITIONS

STIMULATES Na (sod i urn) SEWAGE

BACTER lA Fig. 9 discusses one of the major problems caueed by increae~ed nutrients, the algal bloom. Algae take up phosphates very fast. Inorganic phosphates are used first, then algae possessing suitable enzymes can use the organic form, which is also abundant (Kramer et al, 1972). This may be one of the factors which gives certain species an advantage. Blue-green algae are usually the offenders. Possibly, their need for sodium and potassium gives them an advantage when these are present. Bacteria are stimulated by an increase in nutrients, and may be supplying needed vitamins for the algae (Provasoli , 1969) . We wish to emphasize that the link between nutrients and unpleasant results such as algal blooms is a complicated one, with many feedback relationships. Much more study needs to be done in this field.

It is generally felt that controlling the phosphorus input is more crucial than controlling that of nitrogen. Thomas (1969) presents several reasons, including:

1) Even in low-fertility systems, where little phosphate is present, the very soluble nitrate is abundant; 2) More nitrogen compounds than phosphate run off of agricultural land;

3) Many natural nitrogen sources are uncontrollable,s~~ch as those in rainwater, ground water, and nitrogen-fixing organisms;

4) Addition of phosphate alone can stimulate growth of blue- green algae and bacteria. This has led to the idea that phosphorus may be the limiting factor in algal nutrition. However, the picture is probably more complex than this. Relative abundances of carbon, nitrogen, and phosphorus vary from system to system. The effect of availability on growth is also uncertain (Kramer et all 1972) ;

5) Phosphorus can be removed from water, by methods such as the addition of aluminum sulfate. A study of this is now underway in Wisconsin (Peterson et al, 1973).

As was mentioned briefly above, the nutrient level and resultant algal growth affect the availability of oxygen. Lakes get their oxygen, which dissolves in the water, by contact with the atmosphere and from photosynthesis. Wind increases addition of oxygen to the water. In winter, an ice layer blocks addition of more oxygen. If there is snow on the ice, little light gets through, plants photosynthesize at a low rate, and not much carbon dioxide is exchanged for oxygen. On the other hand, some respiration continues even in cold weather, using up oxygen and producing carbon dioxide. Thus, oxygen levels in a lake can be quite low by the end of the winter. The Department of Natural Resources has projects to aerate water in certain lakes for protecting fish from winter kill. Oxygen levels may also become very low due to algal blooms caused by high nutrient levels. Decomposition of the dead algae by bacteria consumes oxygen. On hot, windless nights, the rate of chemical activity may be high, no light is available for photosynthesis, and little oxygen is added at the surface. If algae are decomposing at that time, the oxygen level may become very low and a fish kill may result (Hutchinson, 1957) . According to Larken and Northcote (1969), fish may be more permanently affected by low oxygen levels if the nutrient input remains high. At first, there may be an acceleration of their growth rate. With greater concentratiocs, however, cold-water species in deeper lakes may suffer. Low oxygen levels are most pronounced in the deeper colder region where bacterial action occurs and there is little light. These fish are pushed upward by their need for oxygen until they are squeezed against the warmer surface layer they are not adapted to live in, and may become extirpated in the lake. For example, the cisco is believed to be lost from Lake Mendota in recent years, but remains in Fish Lake. WETLANDS AND WATER QUALITY

The principles outlined above can be applied to shallow bodies of water such as marshes, as well as to lakes. In fact, there is no abrupt dividing line between the two. Peat deposits such as those found in Dane County represent a storage of nutrients over a long period. This alone is not proof that the marshes in question have or ever did have nutrient-rich waters. One might have any of several combinations of situations: nutrient-rich water that flows through rapidly enough so that there is a low rate of deposit; cycling of sediment nutrients back into the water so that the deposit builds slowly; nutrient- rich water with a high net deposition rate; nutrient-poor water with a low deposition rate that has, over millenia, built a thick peat layer; or nutrient-poor water with little deposit. Geological and hydrological studies in Dane County, however, indicate calcium-rich, moderately nutrient-rich waters, suggesting that slow deposition with much chemical cycling and periodic peat loss through oxidation have operated here. It would be useful to know how long ago the peat deposits in various wetlands reached their maximum possible height above the water table. Paleolimnologists study nutrient conditions of the past, but a cursory inventory such as the present one cannot hope to reveal such information. In what follows, the importance of nutrient storage in marshes is emphasized. When eutrophic conditions appear, they may well indicate a rate of nutrient inflow which is greater than the storage rate. A marsh, being relatively small and shallow, is less able to handle such an inflow of nutrients than could a larger, deeper body of water. That is, the symptoms of eutrophication would more readily appear.

A marsh has a larger relative surface area exposed to sunlight, where algae and submerged, floating, and emergent plants (macrophytes) can grow. Since the bottom mud is warmer, even when shaded, chemical processes are faster than in a deep lake. During a high wind, a lake surface picks up oxygen from the air faster than it does when calm. However, emergent and floating plants in a marsh inhibit wave action and use up much of the oxygen that is available to this calmer surface. They also tend to shade out plants nearer the bottom, and produce considerable detritus which bottom bacteria consume. The results are a low oxygen availability and a high rate of consumption near the bottom. Again, the chemically reduced state of bottom sediments causes nutrient liberation into the water. Methane bubbles, frequently seen in marshes, carry nitrogen with them from the sediment into the water. In their studies, Brezonick and Lee found that the low oxygen levels allow denitrif ication (NO34N2) to occur, removing the nitrate which inhibits methane-producing bacteria (Lee et al, no date) . Although a certain natural richness is characteristic of southern Wisconsin lakes and marshes, very eutrophic conditions in marshes are not normal. Such situations are suspect of being caused by cultural eutrophication. Even under enriched conditions, algal blooms are found only in the more open portion of marshes. Due to the shallowness, many macrophytes can compete with the algae for nutrients. For instance, a water lily stand effectively shades out algae in the water below the floating leaves. Various rooted plants offer shelter from the wind, allowing a surface layer of tiny floating duckweed plants to develop. These duckweeds and the algae and invertebrates associated with them use a large quantity of nutrients and shade and cool the water below, as well as deplete the oxygen supply much as algae blooms do. However, duckweed is not an indicator of eutrophication by its presence alone any more than algae are; the abundance of either is the criterion.

STUDIES BY BENTLEY AND AMUNDSEN: UNDRAINED WETLANDS

Further discussion of the effects of nutrients on wetlands and of wetland outflow on conditions downstream is based on the work of G. Fred Lee and his students, B. M. Bentley, R. W. Amundsen, and others (Lee et al, no date; Bentley, 1969; Arnundson, 1970). Their research falls into two general categories: the processes in a normal undrained wetland of the sedse meadow and ieep marsh types, and their effects on water qualify downstream; and the availability of nutrients in farmed and unfamed portions of a drained marsh.- Nutrients enter a marsh from ground water, surface water, rainfall, and gas exchange with the atmosphere. They leave the nutrient cycle of the marsh by sedimentation, gas exchange, and outflow. This is the same picture as found in lake studies, as shown above. Differences are mainly the large amount of photosynthesis and the large amount of storage in a marsh.

Two undrained marshes were studied, Waunakee in Dane County and Horicon in Dodge County. Waunakee Marsh is discussed in detail in the present study. It is a typical sedge meadow with springs and flow channels. The major disturbance is overland flow from agricultural land. Horicon MarshinDodge County contains both deep water and sedge meadow portions, and is of a physical and biological type also found in Dane County. However, it bears a nutrient load from cheese factories, vegetable canning companies, a creamery, and domestic waste water treatment plants, as well as agricultural runoff. Bentley had hoped originally to calculate the amounts of chemicals flowing into and out of the marshes in question; however, a complete hydrology study on each was not possible due to lack of funds. Ground water inflow and evaporation are difficult to estimate accurately. A more complete picture of nutrient inflow and outflow might have made some results clearer. An interesting result of ~entley'swork is the observation that considerable denitrification occurs in the marsh. That is, nitrogen compounds in the marsh are changed to nitrogen gas (N2), and become unavailable for further plant use. This occurs during low oxygen levels. He found almost no nitrate or ammonia leaving Waunakee Marsh, despite a nitrate inflow, A further interesting result was that there was a release of nutrients with high water in the spring. Some ammonia is released at this time. Soluble orthophosphate discharge also increases. Phosphorus storage in the marsh is not complete; that is, some is in the discharge water during the entire year. However, the spring discharge is noticeably larger, and high enough to ~oi~tributeto algal blooms downstream. Horicon Marsh gave similar data for nitrogen. Denitrification and nitrogen uptake by growing plants occur in the marsh, giving low discharge levels of nitrate and ammonia as at Waunakee. Phosphorus discharge is much higher than the concentration usually associated with algal blooms, but much lower than that of waters entering overland. The large decrease in phosphorus in Horicon Marsh contrasts to a slight increase in Waunakee, a point needing further consideration. High flows transported more nutrients off of Horicon, as they did at Waunakee. Oxygen levels were studied also, and found to vary during the day and year as expected due to demands by growing and de- caying organisms. Concentrations of several other elements dis- solved in the water were measured and their relation to nutrient availability discussed. For more detail, the reader is referred to the thesis by Bentley (1969).

RESULTS OF RESEARCH; AN ACTIVE FIELD OF DEBATE Generalizations and suggestions were drawn from this work. Beneficial effects of marshes on water quality were found to be nutrient storage, de-nitrification, precipitation of certain trace elements so that they became unavailable for growth (no longer in solution), trapping of organic sediments, and reduction of fluctuations in stream flow. Possibly nutrient dilution by ground water also occurs where concentrations in entering surface water are relatively high. Possible adverse effects include nitrogen fixation (found since to occur in Dunn's Marsh - Lonargan, 1973), although the net result still appears to be favorable. Since little nitrate or ammonia is found at the outlet, probably this is also stored in the form of organic nitrogen (various other compounds). Peat is known to be nitrogen rich. Lee,et al, list taste, odor, and color of the water, effects on water quality at the outlet due to discharge of organic matter, and low oxygen levels within the marsh tending to exclude fiah as possible adverse effects of wetlands, However, many wetlands are considered important in supporting fish spawning. Bentley suggests removal of nutrients from the outlet of a wetland during high water flow (Bentley, 1969). A later paper suggests in more detail that precipitation of phosphorus with alum could be tried (Lee, et al, no date). Several interesting questions arise from this work. Bentley compares inflow from springs at Waunakee with the outflow and finds total phosphorus even increases and soluble orthophosphate doesn't decline. Then he compares this result with Horicon, where both decline significantly. What conclusion can be made, then, as to the effect of a marsh on phosphorus levels? He notes that the incoming levels from the West Branch of the Rock River are very much higher than those in the Waunakee springs, as would be expected since ground water is low in phosphorus. Probably there is ground water dilution of phosphorus in Horicon. Bentley found ground water concentrations much lower than surface values for all nitrogen and phosphorus forms studied, so dilution is quite possible. Two other possibilities are important: (1) phosphorus could be removed down to a certain concentration by processes other than dilution, such as incorporation into marsh vegetation, and the incoming level at the Waunakee Springs may already be closer to that concentration; (2) more importantly, at Waunakee, Bentley did not consider nutrient inflow overland from a large watershed with agricultural souxces. This may well be large enough to invalidate his conclusions regarding the nutrient inflow from springs versus the total nutrient outflow. Our point in discussing this is that although nutrients come out of marshes, the situation probably would be worse if the marsh were not there, even neglecting the drainage effects discussed below.

EFFECTS OF DRAINED WETLANDS

Bentley (1969) and Amundson (1970) both studied the effect of drained marshes on water quality by leaching soil samples from Shakey Marsh, Dodge County, Wisconsin. Some of this marsh was .tilled, drained, and under cultivation, so that the water table .was ten to twelve inches below the soil surface allowing aerobic ,conditions. The cultivated part was fertilized, whereas an :.uncultivated region was not. Potassium and phosphorus are added -to marsh soils for farming. Amundson compared samples from culti- ..vated and uncultivated regions, the former also under anaerobic :conditions. Both the soil and the water leachate from it were tested. The soil was fertilized annually for crops. This increased the phosphorus concentration in the soil and allowed for a greater leaching of total phosphorus and orthophosphate than found in uncultivated soil. Amundson presumed that the added phosphorus was less tightly bound to the soil. Presence of oxygen appeared to make no difference in phosphorus leaching, so the drained condition probably did not speed up the loss. However, Bentley (1969, p. 107) found less total phosphate leaching from drained unfertilized soil than from undisturbed Waunakee Marsh, due to plant decay and chemical changes in the natural marsh. When phosphorus is leached, the process begins immediately. Nitrogen acts quite differently. This was also added in the fertilizer and resulted in increased organic nitrogen and nitrate leaching, especially under aerobic conditions. Nitrogen leaching actually increased with time, probably due to action of micro-organisms making it soluble. Plowing loosens the soil and aids the flow of nutrients away from it. The net result then is an increased rate of runoff of nitrogen and phosphorus, as well as other nutrients such as potassium, when marshes are drained and cultivated.

SUMMARY This research points out several values of natural wetlands as well as threats to water quality when they are drained for cultivation. We wish to emphasize these points by listing them again. Values of undisturbed wetlands Stabilization of water table, including flood control Physical trapping of sediments Chemical trapping of organic material Storage of nutrients such as nitrogen and phosphorus, at least to a limit determined by amount of living material, cycling rates, etc. Precipitation of trace elements used in plant growth Opportunity for nutrient dilution by ground water to take place where wetlands are also discharge areas Denitrification, i.e. rendering of nitrogen inaccessible for most plant use Provision of opportunity for seasonal phosphorus removal at outlets Possible undesirable effects of undisturbed wetlands Addition of organic material to water downstream Addition of color to water Release of nutrients during high flows in spring Breeding sites for mosquitos and biting flies in some cases Undesirable results from wetland drainage Loss of above natural buffering and balancing function Addition of nitrogen and phosphorus to discharge waters, especially if fertilizers are used Addition of organic matter to discharge water ECOLOGICAL CONCEPTS

The concept of the ecosystem was developed in the 1930's. It is a way of visualizing the physical and organic systems together. An ecosystem of arbitrary size depending on the objective, is chosen for study. An imaginary box can be placed around the system, and flow of energy and materials in and out can be measured at least in theory. Within the system, there is a complex relationship between the physical environment and the organisms present. Organisms can not only influence other species, but to some extent their own physical environment as well. We shall briefly discuss some of the physical influences.

SOIL AND VEGETATION Wetland plants, like upland plants, are affected by soil types. Sand, silt, marl, and peat each support typical plant species. These can be used as indicators of soiltype present. On the other hand, marl and peat are made by organisms. Marl, a lime layer, is deposited on the bottom of a lake. A researcher making a core of marsh soil and finding a marl layer below the peat layer knows that the area must have been a lake bottom at one time. The large alga of the genus Chara aids in the deposit of calcium carbonate (lime) perhaps more than any other species. Fresh-water snail and clam shells also contribute, and remain visible in the deposit. Some work has been done with the peat deposit of South Waubesa in trying to identify these shells and correlate their presence with former habitats (Dewitt, Huseth, pers. comrns.).

Sedges growing on the peat are at the same time building it up. Fig. 10 shows a typical sedge-peat-microclimate inter- relationship which is self-perpetuating. This is a dynamic situation in which effects are hard to separate. This cyclic process starts with the pioneers moving in on an exposed, already existing substrate. Sedges of various species can in-- vade on various substrates, ~uchas sand or organic material from other wetland plants.. Wet shores can be invaded and the sedges can grow out toward deeper water. A sedge meadow has one of the aspects of a climax community in that once the peat is established, the roots of the sedges cannot reach any mineral layer below. The sedges and associated plants are growing on a substrate of their own making. See discussion on climax under nSuccessionn.

WATER AND VEGETATION

As we have seen, water also plays an important part in the ecosystem. The nutrient level in the water affects the amount and type of vegetation growth. A number of other factors FIGURE 10 SEDGE - PEAT I NTERRELATIONSHIP

LITTLE OXYGEN REACHES SOIL, DECAY INHIBITED BY OXYGEN LACK, TOXIC SUBSTANCES

DECAY INHIBITED BY ;LOW

SEDGES MOVE IN, I.IATC~I AFFCn WMlCnLUUUCV PROSPER IN --OENSE hrr+ CAII PEAT ACCUMULATES LOW--.- .ARFA ...-. . MI r L l MATE rcn~~UIL 9 -.-- GROWTH, CROWD IS COOL, HUM1 OUT PI Oh, ABUNDANT PEAT 1 PRODUCED. . ------SURFACE FLOW IMPEDED PROTECTED BY PEAT ABSORBS WATER LIKE SPONGE ROOT STRUCTURE, SHAD l NG EVAPORATION INHIBITED BY HIGH HUMIDITY FlGURCII PUNT SULCESSIMItM A SdUTHEAS7EREIYlSCOIlS l ly msn (SEETEXT FOR DISCUSSION) FROM VML , 1969

marsh, wet prrtrls sane tamarack no trees or shrubs In rmrsh. To HE sugar mple (to 36'' dbh), to SY bur oak opening, due to f {re succession satback due to hlph rater

Ik,000 B.C. 2,400 B.C.' glaclcr retreats,' peat dcl shallw lake basln, starts on logglnp btgtns on surrounding upland marl dtposlt starts topof marl

preset el-t f l rer and oscll lrtlnq water Icvet keeps area In ffarsh stape

,+4 not mch chanqe shrubs bsgln to appr - -.,-,+,?~-~ ' A,..-.., ; ,:. . .. > . . .- .. , ,..- :, ^..*I - .. .,..---?- V- ."-. - , -,- ...-.. . ,. -,- - . -- . . 1 I .. I -' . . - ., . .-.. . . --L..-,- -- -.A- L. . 'd. ', --.. - - -...... I .:-~. . -L.__1,--.1, . --1. .. . 1870 1880 ' 1890 1900 w w,- -Gi 19 10 1926 $2 5: drying cut of marsh beglns, "--tc. - + due to dm r-sl. clearing, Z, drainage. farming 3"ens dylng due to shrubs and nettles .$ wet prrlrlc goes aroslon areas not prw under aspen, 7= fungl, Inflamb!c tmard shrub carr burned In !930 advarrc l ng grcwthdense, hardwoods apptaring also con6i t i on . . - . .." I r I I I I I I I I - . . I d - 1970 1920 marsh contlnuss lm- 1930 drought w w Iy40 drought 1950 I960 U)- to dry out continues u ends +- m. * - ;Cn OI 5%: avn w v m- dry enough for DI J 0 7 r - hsylng, Lanuracks 2 2 2 urms-* - c nn' u II J cut an 0 - Zrmwa $ -seed dispersal. Many wetland plants have floating seeds or vegetative parts which break off and are carried in the water, and many species germinate best when stranded on wet mud.

LIGHT AND VEGETATION

Light is an important factor in any ecosystem. Light from the sun is the energy source that drives the system. However, along with sunlight comes heat from the sun. As plants and air warm up, the transpiration rate increases. Since plants with waterlogged roots cannot transpire rapidly, they are adapted to save water . For i'nstance, tussock leredges have a mechanism that folds the leaves to slow water loss. In many plant communities, the effects of too much light are offset by shade from larger plants. This is especially noticeable in the forest. Among wetland communities, only floodplain forests, tamarack bogs, and various shrub communities have this advantage. On the other hand, very deep shade is a drawback, since not enough light energy reaches the leaves of the shaded plants. This is one reason sedges die out when shrubs invade. In a deep marsh, light plays an additional role. There is an abundant plankton, or microscopic plant and animal life, in the water. Deeper organism receiveless light than those near the surface; this is especially true if there is suspended silt in the water. Layers of floating plant leaves, such as duckweed Or waterlily pads (Pl. 4), severely shade out plants' in the water below. Heat and light from the sun also affect water temperature. There is an especially marked effect in a deep marsh in early spring. When a dense duckweed layer has survived the winter, it holds the energy near the surface. The water temperature in the duckweed-plankton layer can be 15-25°F above that at the mud surface less than a foot below.

CLIMATE AND VEGETATION

All ecosystems are subject to the local climate. In southern Wisconsin, before white men settled, prairie,oak openings, a few protected forests, open marshes, fens, and relic bogs were present, As one travels north into a cooler region or east into a moister region, one finds the wetland as well as upland communities common in southeastern Wisconsin are replaced by somewhat different ones. The eight wetland communities discussed below are a collection which results from Dane County's local topography, geological history and climate. Relic bogs are of particular interest in this respect. For a time after the glacier melted, the climate was cooler and moister. According to studies of bog peats, the bogs got started at that time. Do they owe their present existence to that history, or are they viable communities that could get a start even now in a low, cold, wet area? ~nfortunately,bogs of all sorts are being drained in southern Wisconsin at such a rapid rate that we may never have the answer.

A bog is a good example of a microclimate, or small scale climate. Cold air settles there at night, and the relative humidity is high. Since the peat and sphagnum on its surface insulate the water, and since the water body itself, especially if deep, has a high heat capacity, the bog temperature tends to stay near the average for the season. We need to know more about whether the bog plants perpetuate a cool moist climate for themselves. For a more detailed discussion of the effects of the physical environment on plants, the reader is referred to Daubenmire (1959).

FOOD WEB, ENERGY FLOW, NUTRIENT CYCLING Concepts related to that of the ecosystem are those of food web, energy flow, and nutrient cycling. We met nutrient cycling already in the discussion of eutrophication. Often the ecologist studies terrestrial (land) or aquatic (water) systems, but wetlands cut across this line. The best way to describe a food web is by a representative diagram (Fig. 12). The most important factors to note are as follows: Fl GURE 121, A PARTIAL FOOD WEB - 1. The food web is composed of many interconnecting chains, from the producers (plants) through primary consumers (herbivores or plant-eaters) to additional levels of consumers (predators), and finally to the decomposers (bacteria, fungi). Energy from the sun is used by plants to build organic compounds. When the herbivore eats the plant, these compounds become available to it. This is important, because animals cannot make their own food. The animal uses these compounds, or food, and in doing so, releases some of the chemically stored energy from the sun. Even though the animal stores some chemical energy in new compounds, there is a net energy loss as it maintains itself. This means that the predator that is next in the chain can make use of only some of the food energy the herbivore ate. Anyone who has raised dairy or beef cattle is aware of how much food must be put in to get Out a product, even if the whole animal could be eaten. On each feeding level, therefore, there is less total energy available, and fewer members of that level.

2. Nutrients are continuously cycling through the food web. In this case, there is not a loss to the system at every step, as there is with energy. However, nutrients become available in waste from animals during life and later during decomposition after death. Not everything is available to herbivores and predators. An example would be nitrogen (Figs. 7 and 13).

3. There are on each level many food sources (plants or prey items) and many consumers (herbivores or predators).

For a further discussion of food webs, energy flow, and nutrient cycling, see Colinvaux (1973) Chapters 9-15 and Smith (1966) Chapter 3.

COMMUNITY

The concept of community is an important one for the present survey. A community may refer to a grouping of all the plants, all the soil organisms, all the plankton, etc. The concept is nost generally used for plant groupings. Whittaker (1970) discussed the response of communities to environmental gradients. Suppose one were to walk across a large area covered with vegetation, going from a wetter cooler region to a warmer drier one. This might occur over a distance of a few feet to a mile or more in our area. As the environmental conditions become warmer and drier, the plant species found in the native vegetation change. The edge of a wetland is an unusually sharp boundary in some cases, especially at the edge of a deep pothole. In general, however, plant communities are not definite associations of species with abrupt boundaries. Species tend to overlap to a greater or lesser extent. Each species responds to the environment in its own way. The analysis of communities versus environmental gradients is still an active field. The authors do not know of any such study in wetlands to date, however. FIGURE 13 NITROGEN IN THE FOOD CHAIN

ATMOSPHERE N3:

(F I XATION~)I O3 N l TRATES

ORGAN l C N COMPOUNDS:

BACTERIA, ETC.-kg DENITRIFICATION. Since plant communities do not have distinct boundaries, they cannot easily be classified into natural groupings. How- ever, they can be broken into groupings for purposes of study and discussion. These should be recognizable by simple criteria, even though they may be variable (Curtis, 1959). Communities vary greatly in species diversity in different environments, and the reasons are still the subject of much controversy. In wetlands one finds, for instance, that there is a large diverse plankton community, but often little diversity of emergent plant species in a deep water marsh. On the other hand, fens and wet prairies have diverse plant communities, but plankton are absent or nearly so. There is at present no way to rate the "value" of one situation over the other. Spatial distribution of plants in a community may be random (location of each plant unaffected by the presence of others), regular (each plant location tending to be away from that of others of its species due to some known or unknown factor), or clumped due to reproductive processes (Whittaker, 1970). Despite the difficulties in delineating communities in space, and despite the fact that they differ from place to place in composition and relative abundance of species, there are benefits from the community approach. Although species compositions reflect adaptations to local environments and a history of chance factors influencing distribution, more or less similar groups do occur in similar environments and can be used as a basis for study. Curtis (1959) felt that the similarities in species composition result from the influence of relatively few commonly occurring dominants, which affect the conditions under which the other plants must grow. This is apparently true at least in some circumstances, but is a concept which needs further field work.

COMMUNITIES COVERED IN WETLAND SURVEY In the present report, the following communities will be discussed: River floodplain forest (P1.5)--deciduous tree community, tolerant of flooding, on periodically disturbed soil, usually alluvial deposit, along a river course. Deep-water marsh (Pl. 6)--community of emergent, floating, and submerged aquatic plants in water which is always or usually permanent (except during extreme drought) and often includes the greatest depth the emergents will tolerate. Shallow marsh (Pl. 7)--similar plant community existing in shallower water, often temporarily dry in late summer. There is no strict dividing line between this and the above. They are separated only for purposes of discussion. Sedge-grass meadow (P1. 8)--plant community on waterlogged to wet soil, seasonally wet in spring, consisting predominantly of certain sedges and grasses. Low prairie (Pl. 9)--community of certain characteristic grasses, sedges, and forbs on moist mineral soil. Fen (Pl. 10)--community of characteristic grasses, sedges, and forbs on.a waterlogged alkaline organic soil. Bog (Pl. 11) --community of characteristic plants, including sphagnum mosses, certain sedges, forbs, shrubs, and trees on waterlogged acid organic soil. his may grade into the above on a site where acidity varies. Alder thicket--community dominated by alders, often near cool springs or streams. Shrub carr--community of shrubs, invading sedge meadow and increasing in density with time, apparently as a result of disturbance. We also consider the stream valley marsh and meadow in a separate category, but this is due to local topography (di- sected, unglaciated) rather than its being a separate community 1.12). Several of the above communities are found along stream valleys.

A more detailed discussion of the above communities follows. It should be again understood that these intergrade.

River Floodplain Forest Floodplain forests are placed under lowland southern forests by Curtis (1959). He finds these forests both in river valleys and lake plains. Both are aITuvial (water depositi~nal)~ situations, and both occur to a limited extent in Dane County. Our principal river floodplain forest is, of course, along the Wisconsin River near Mazomanie. There is often submergence of soil and tree roots during spring floods; at other times the forest floor may be dry. When the flood waters subside, the soil warms up and oxygen becomes available to it. Then the spring wildflowers appear rapidly, and later a tall growth of forbs such as jewelweed and wood nettle (La ortea canadensis) . icans) typically +k-c 1 s trees in Wisconsin only in the forests associated with river valleys.

River valleys in general may allow more species diversity than uplands partly because of the more adequate water supply, partly because they act as corridors for the species to spread, and partly because their topography allows many micro-environments from cool, moist north-facing canyon walls to hot, dry south-facing slopes. A southern tree which has reached Dane County along the Wisconsin River valley is the river birch (Betula nigra). It is our impression that this river valley shows southern inlluences as far north as Sauk City, but not above the artificial Lake Wisconsin; in other words, that a transition zone has been wiped out. Further study should be done on this point. - -- Black willow (Salix nigra) and cottonwood (Populus deltoides) (Pl. 13) are pioneers that invade quickly on sand bars and other disturbed wet soil. As well as being common in the floodplain forest, they can be found on many spoil banks throughout the county. Silver maple (Acer saccharin&), American elm(Ulmus americana) , swamp white oak (Quercus bicolbr), and sometimes black ash (kFaxinus nigra) and green ash (Fraxinus pennsylvanica) are common to dominant tree species. Deep Water Marsh

Deep water marshes often occur at the edgesof lakes, or in depressions almost large enough to be considered as lakes. This is^ a feature of the glaciated-portion of Wisconsin, which includes the northeast three fifths of Dane County. Generally, broad- leaf cattail (Typha latifolia) grows out to a depth of about three feet. At this depth the interwoven root structure is floating, and if high rainfall increases the depth, portions of the root structure will break loose and float around the open portion- of the marsh. Often these "islands" become re-est-&lished in new locations. This process has been observed twice in both Marx Pond and Dunn's ~arkhduring wet years. Cattails (T ha spp.) are the most common deep-water marsh vegetation, but narrow+eaf (T. angustifolia) (P1.6) is'locally common, especially along the Yahara River. arrow-Tea£ is structurally different from broad-leaf * cattail in that it builds a firm peat layer under its root system. It also seems to prefer a firmer substrate such as sand. This peat layer can be several feet thick. River bulrush (Scirpus fluviatilis) is sometimes found in deep-water marshes, but is more typical ok shallow ones. Hardstem bulrush (Scirpus acutus) is an emergent of deeper water that is not often tound in Dane County, certainly not in the extensive stands more typical of the cooler, softer waters of northern Wisconsin.

Some other emergent aquatic plants typical of deep-water marshes are pickerelweed (~ontederiacordata) (PI, 14) , which is rare in

Dane Countv, stiff wa~ato(Sasittaria- w risida),. . and wild rice (Zizania aqkatica) , formerly common, but-now rare due to carp action. Some plants ot open lakes which have been found in Dane County, but are uncommon or rare in southern Wisconsin, are water shield (Brasenia schreberi) (Pl. 15) and Megalodonta beckii (Pl. 16) . In general, a deep-water marsh is dominated by cattail, although in Dane County there is one exception that is entirely river bulrush with no cattail at all. I Probably the animal with the greatest effect on the vegetation structure of the deep marsh is the muskrat. Only outbreaks of disease or insect pests can approach the work of the muskrat in shaping patterns of vegetation interspersion. Since the muskrat's food preferences are broad, most aquatic emergent species are affected. It also sculptures the bottom by makipg channels and deep areas around its houses. Some typical bird species of the deep marsh are the black tern (nest, P1. 17) and the least bittern (male incubating, P1. 18).

Shallow Marsh Shallow marshes contain most of the same plants as the deep ones. Hardstem bulrush and pickerelweed, which grow in deep water only, are missing. Shallow marshes are not always dominated by cattail. Stands of lake sedge (Carex lacustris) (Pl. 19) are common throughout the county. Often the cattail and Xake

Sedge Meadow .. -- ~~stsedge meadows in southern Wisconsin have important stands of tussock sedge. Stout (1913) listed this sedge as twice as abundant as the next most common species, bluejoint grass (~alamagrosti'scanadensis);(Pl. 22), in his study of 8 hay meadow at tne Madison rairgrounds. Also important, but less so, in decreasing order are Carex sartwellii, water horehound (~~co~ua uniflorus), Carex aquatilis, Carex prairiea, manna grass (Glyceria striata), Carex lanuginosa, big skullcap (Scutellaria galericulata), marsh blue violet (Vhla cucullata). Also coinon in sedge meadows, but visible only in spring, is marsh marigold (Caltha palustris). The gradation from sedge meadow to low or wet prairie can be very subtle. Turk's cap lily (Lilium superbum) (Pl. 23) is found in both.

PLATE 16 MEGALODONLA BELKII, A RARE PLANT OF. OPEN WATER

PLATE 17 BLACK TERN NEST

PLATE 18 MALE LEAST BITTERN ON NEST, MARX POND YLA'L'E IV TUFFED LOOSETRIFE, HOOK LAKE

PLATE 19 LAKE SEDGE IN SHALLOW MARSH, LOWER MUD LAKE (M. FIFIELD)

PLATE 21 BLUE FLAG. HOOK LAKE

Wet prairies are rare now because they were on easily drained mineral soil. Only a few pockets remain, notably in Dunlap Hollow, Sugar River, Lodi Marsh (although disturbed), and the Arboretum. The last of these is a partly restored area. Cordgrass (Spartina pectinata) (P1.24) is an important species. The small stands or cordgrass in many parts of the county are suggestive of former low prairie locations. Some diagnostic low prairie sedges are carex tetanica, Carex conoidea, Carex buxbaumii, Carex haydewknvexLanuginosa . Curtis did not study the low prairie sedqes,-. and has no record of these. C. bicknellii is also in dry prairie and C. lanuqinosa is also in sedge meadows, but they overlap in wet prairie. Many of the forbs found in low prairie are also found in mesic (medium-dry) prairie and in fens. A few are valerian (Valeriana edulis), bayfeatner (~iatris~~chnostac~y~)(foreground, P1.9) , prairie phlox ,-. - . - ?catheon meadia), golden alexander

-Fen Curtis (1959) stated ". . . a fen is a grassland on a wet and springy site, with an internal flow of water rich in calcium and magnesium bicarbonates and sometimes calcium and magnesium sulfates as well. Frequently, the fen is on a hillside over- looking an existing or extinct glacial lake. . .". Fen soil is a form of peat, or organic deposit, that oxidizes little because the seepage keeps it waterlogged. Due to its alkalinity, bacterial action is presumably increased, causing a finer soil than that found in sedge meadows and bogs. The fen contains many of the low prairie species, many sedge meadow species, plus some of its own. Some that are unique in the fen are grass of Parnassus (Parnassia qlauca),- small white lad~sli~~erorchid . P1.25) lesser fringed gentian (Gentiana .-*a. .. candidum) _-, procera)- , Ka lm's lobe1 (Lobelia kalmii), Carex sterilis, a bromeI qrass (Bromus kalmii') , ~iddcell Is goldenrod (Solidago riddeliii) ( PI. lo), aiia , rush-like aster (Aster juncitormis) . Five species found in th fens and bogs are bog birch (Betula sp. [sandbergii?-1 (P1.26) sage willow (Salix candida) , boggoldenrod (Solidago ul.iginosa) , nk St. ~ohn'swort r~ypericum(Triadenm) virginlcum] and marsh inquefoil (Potentilla palustris) A , . . - . . prairie species that is important In rens 1s blg bluestem (Andropogon gerardi). A sedge meadow species aleo found in fens is Carex stricta. Some fens contain a plant of the far north, the artic bulrush (Scirpus caespitosus). Fens may be the only habitat of two shrubs, autumn willow (Salix serissima) , study, in cooperation with the Arbo: edge of fens, relic bogs, low prairies, and sedge meadows, and their relationships. In this report, the term bog is used for any community on acid.peat, with or without trees. This is a break with usual .pract.ice, but the presence or absence of trees at a given time in a particular area is less diagnostic than the presence of acid peat. Classifying bogs.with trees under "swamps" is mis- leading, since other southern swamps are not generally on peat. Bogs may be more closely related to certain northern swamps (in regard to process), but this point may need further study. Acid peat is first invaded by pioneers such as bog cinquefoi (Potentilla palustris) (Pl. 271, sundews (Drosera spp.) (Pl. 28) , and various rushes (Juncus spp.), spike rushes~leocharissgp.) and sedges (Cyperus 'spp.-). The mat is typically built out over water by wiregrass sedge (Carex lasiocarpa) (Pl. 29). This, in turn, is invaded by Sphagnum mosses (Pl. 30). Growing in this

, possibly other sedges, and cranberry (Vaccinium macrocarpon). The common bog- shrub in southern Wisconsin is leatherleat (Chamaeda~hnecalyculata) - (Pl. 29). Other shrubs include pink- spirea (Spiraea tomentosa) , bog birch (Betula sp. s'andber ii?]) (~1.26) and poison swnac (Rhus vernix) . The f imvader[* is tamarack (Larixlaricina) (Pl. 31) .

Alder Thicket

In alder thickets, the alder (Alnus incana) grows densely and is a strong dominant. A mixture of northern and southern sedge meadow and woodland plants grows under the shrubs.

Shrub Carr A final community must be considered which is probably the result of disturbance. This is the shrub carr. Apparently, according to old records (Chamberlin, 1882), shrubs were not common on sedge meadows. White (1965) could not find shrub carrs that had no history of disturbance. vogl (1969) found shrubs coming into a sedge meadow after the water table was lowered, and again after further lowering. Once shrubs, such as Bebb's willow (Salix bebbii) , pussy willow (Salix discolor) , sandbar willow (Salix interior), and red-and-greemalix petiolaris), and red-osier dogwooa(~ornus stolonifera) are abuxant, the sedges are shaded out. The peat is dry and above water level, no new peat is being made by sedges, and sedges are no longer protecting the peat surface from oxidation. The result seems to be lowering of the peat, leaving the shrubs "on stilts". Perhaps the shrubs will eventually die out as the peat oxidizes down to the water table. A common further development in shrub carrs is the invasion of exotics, such as honeysuckle (Lonicera bella: tatarica x morrowi) and buckthorns (Rhamnus ca'khartica and ran ula).se are very tolerant of shade and are little k&&-y rabbits and deer and can replace the native shrubs, reducing the wildlife value of the carrs.

PLATE 28 SUNDEWS , HOOK LAKE

plw-r-d-.I~ plw-r-d-.I~ -- - = - - I ' #

PLATE 29 WIREGRASS SEDGE , AND LEATHERLEAF,

1 HOOK LAKE

1 w

PLATE 30 BED OF SPWAGHUM MOSS, HOOK LAKE In Dane County stream valleys, a mixture of wetland comi munities can be found. This includes fen and low prairie especially. Acid sand plants and alkaline seepage plants may occur together. Sedge meadow and shallow marsh are also present. In Dunlap ~ollowthere is a berm on each side of the stream due to ditching and spring floods. On the side away from the stream are areas of shallow marsh, fen, prairie, and wet sand, with sphagnum moss. Since stream valleys appear to have an unusual diversity of communities, the loss due to pasturing and ditching is all the more unfortunate .

SPECIES DIVERS'ITY

The diversity of species has long fascinated ecologists. Many attempts have been made to discover why some geographical areas and some ecosystems have more species diversity than others. Methods are still being developed and tested to measure diversity. Two points of interest whichhavebeen notedare: (1) therearea large number of plant and animal species present in an undisturbed ecosystem; and (2) a few species are represented by large populations, more by modestpopulations,and many by low populations. The paper by Stout (1913) shows this point well. He found large numbers of tussock sedges (Carex stricta) at almost all of his sampling stations, and this species was twice as abundant overall as any other. He had over 21,000 C. stricta plants; 8 species with from 1,000-9,000 plants; 9 species with from 100 to 900; 33 species with from 10 to 99; and 19 species with from 1 through 9. This type of abundance distribution is commonly found in plant communities. By contrast, agricultural areas aim at one species on each field, suppressing the unwanted ones with cultivation, pesticides and herbicides.

SUCCESSION AND CYCLING

The concept of succession is generally accepted by ecologists, but its applicability has still to be worked out in many cases. In general, the idea is as follows: A bare surface, such as rock or soil is not a suitable environment for many plant species. The few species that can tolerate the extremes of temperature, moisture, and so on, are the pioneers. They tend to establish themselves quickly. Familiar examples of pioneers on fertile soil are food plants and weeds. After the pioneers are established, the environment is altered by them enough so that some less tolerant species can invade. Eventually, the pioneers themselves are crowded out. Each successional stage prepares the environment for the next until finally a community is established that perpetuates itself. This is called the climax. The classic example is the succession on abandoned farm fields. First,the weeds (pioneers) take over, then an old-field community, then shrub and tree invasion by species that do not tolerate shade, and finally, after those trees are well developed, a forest of shade-tolerant trees appears under them. Finally, these last species are reproducing in their own shade and the situation appears to have stabilized. This does not last forever in nature, however, since fires and storms tend to open up the forest again. - --. ..-- In wetlands, the succession is retarded, and even stopped, by a great deal of vegetation cycling. The classical view- point starts with open lakes, such as those made by glacial action; the lakes gradually fill over millenia wish various forms of organic debris and silt from natural erosion, until finally thev are shallow enough for emergent aquatic plants to survive. Tklese plants build up peat layers from the shore toward the center, and meanwhile a small amount of silt continues to be deposited. Finally, the lake is covered with a marsh or bog, still wet but solid enough to walk on. Peat continues to build up, shrubs invade, and finally trees invade. The soil gets drier at every stage until the lakes have been made into land. There are two difficulties with this concept. First, there is so much cycling that succession is greatly delayed and perhaps even reversed. Second, the wetland peat soil never actually becomes mineral soil like that of the upland, and never will support the upland plant community. 1n order to change water to land, it is necessary to have extreme amounts of alluvial (water- borne) or wind-borne mineral deposit, At this point we are no longer talking about succession, but about geological action.

TWO exampleswillbe given toshow how vegetation cycling delays and may set back wetland succession. Vogl (1969) inhis study of plal~t succession in a Jefferson County wetland, noted "Marshland may have existed from one to several thousand years prior to 1836. . . The stability of this stage is considered to have been produced and maintained by oscillating water levels and periodic fires." During the wet spells, related to wetter parts of climatic cycles, those plants requiring drier conditions would have been drowned out. Drought periods would allow fires, which would favor wetland plants over shrubs and upland species. If it stayed dry long enough, the peat itself would burn down and when the water level rose asain, the conditions would be wetter than before the drought. He found that "Indistinct charcoal layers were strati- fied throughout the peat', indicating that there had indeed been many fires. Weller (1965), working in deep marshes in Iowa during a period of water level change, found that such cycling was important in affecting plant and animal abundance and distribution. He noted that short-term changes in succession are not usually considered. Similar changes have been observed by the authors in Dane County. In general, the cycle is as follows: During 8 period of low water, the emergent vegetation becomes dense. The muskrat population responds to this food availability by increasing. There often follows a muskrat "eat-out" of emergent vegetation, causing larger and larger areas of open water. As the openings increase in number, more suitable nest sites for marsh birds are created, and the number and diversity of these species increase. If the water level rises at this time, as it did in Weller's study and at Dunn's Marsh in 1968-1969, the effect is accentuated. Finally, an extreme situation may exist where there is little cover for nesting birds and little food for muskrats, and the numbers of both decline. Weller diri not observe the other half of the cycle, which is perhaps lesk dramatic. The closing in of the marsh begins again as soon as the water level recedes toward the averdge and the muskrats become sparse. This regrowth process is much siower than the apen,.ng up part of the cycle. Year by year more stiff dead cateail'stalks are made available for support and construction of nests. Due to unevenness in the bottom surface and in cattail growth patterns, many openings persist. These are attractive to nesting birds, which tend to avoid uniform dense cattail stands. Not all deep water marshes have the necessary changes in water levels and muskrat populations to cause this type of obvious cycling to occur. We found that certain marshes did not respond greatly to the high water levels of 1973. In general, however, cycling is an important and neglected factor in the control of succession.

We feel that a sedge meadow is a climax community, at least during the millenia that the appropriate conditions are maintained. As we have seen, sedges perpetuate themselves on a substrate of their own making, and when this substrate is raised high enough above the water table that waterlogging decreases, slow oxidation and perhaps fire lower it to water level again. This is a type of stability. Usually, stability is considered to exist in a climax community due to the inter-actions of a diversity of species, but the present case may be due to the existence of one or a few dominant sedge species only. The sedge meadow is further protected by the activities of herbivores such as mice, rabbits, and deer, which eat the new shoots of shrubs. The density of the sedge and grass ground cover, with its shading and competitive root system, also keeps new shrubs from.starting. In other words, adaptation of organisms to a certain range of conditions may lend the stability needed for self-perpetuation. How then do shrub carrs get started? We saw above that lowering of the local water table favors shrub invasion, and in fact, this alone may produce a change beyond the ability of the sedge community to establish a new equilibrium. Man has become a geological force due to his ability to alter water tables over wide areas. As long as the water table maintains its average value, the cycling described above can continue. Changes are limited to fluctuations about an equilibrium condition. However, artificial drainage amounts to a drop of from one to several feet, with no recovery. ~t the same time as drainage occurred, further alterations were being made to the marsh Vogl studied. Despite the slow advance of shrubs, the natural vegetation was able to survive the drier conditions for a while. Fire on dry peat made dramatic changes ( Fig. 11). Vogl (1969) noted "The marsh vegetation was relatively stable before burning, although successional changes began to occur with the manipulation of water levels. . . But where the peat had been burned, the existing vegetation was completely destroyed." On the other hand, where fires were prevented, the shrubs continued to advance. Grazihy was an additional stress on the system. The sedge- grass mixti'lre was attacked and eventually destroyed. Trampling made tussocks higher and drier, and sedges were replaced by pasture grasses that did not completely protect the peat. Where pasturini~has stopped, bare dry peat has become available for shrub invasion. The sources of native willow and red-osier dogwood shrubs are relatively dry, naturally disturbed edges of water courses and lakes. Erosion, ice push-ups, and minor disturbances keep shrubs going, but at a low level.

The invasion of shrubs has been a self-aggravating process. At first, not many seeds were available. Natural burns controlled the sprouts, since grass and sedges, which burned more readily, were abundant. Once shrubs were established, the willows with their wind-borne seeds first and theberried shrubs later, the local seed source increased. The bigger and denser the growth became, the harder it was to burn the'shrubs. Sedges and grasses were not tolerant of the heavy shade and died out. If left alone, the shrub carr areas are replaced.byswamp trees, black willow, cottonwood, box elder (Acer negundo),American elm, silver maple, and green ash. A more serious problem is the invasion of shrub carrs by the exotic honeysuckle and buckthorns, which persist in the swamp.

Where peat has been burned, minerals are available in the ash. ~ettles(Urtica dioica) and aspen (Populus tremuloides) invade, but do not protect the peat from oxidation. Akter several years, the aspens themselves may die out and cause a fire hazard. Nettle, on the other hand, is very difficult to burn. Much of the above discussion is based on observations since 1945 at the University of Wisconsin Arboretum.

It is quite possible that peat loss will eventually bring these disturbed areas down to the new water level and sedge meadow will re-establish. This process may not be complete in our lifetime, however.

A theory which is currently being studied is that as succession continues toward climax, species diversity increases and the system becomes more stable. Colinvaux (1973, p. 237-240) discusses the idea of stability in more complex ecosystems. Stability means lack of large fluctuations due to inside or outside disturbances. The idea is that the more species there are present, the more channels there are for diverting and dispersing the influences of the disturbance. Abrupt population changes should not occur, for instance. The most widely appreciated example of the effects of simpli- fying a community is that of monoculture. The farmer replaces hundreds of species by, he hopes, only one. The results are attacks of pests, outbreaks of weeds, and disease. Since probably the most important way in which the many species in a natural community interact is through the food web, it is easily seen why there are pest outbreaks among the crops. A large amount of one type of food is available, and the pest (herbivore) population increases rapidly. The farmer sprays pesticide on this population, but kills the predator insects as well. It is thought that the major control of herbivore populations is through predation, since they do not consume all the availhle food and are not limited by its abundance (Hairston et al, 1960). Thus, the pest population becomes even more uncontrolled. However, Colinvaux states that it has not yet been established beyond doubt whether or not simple systems undergo population fluctuations due to low species diversity.

Conversely, it is hard to prove that complex systems have stable populations because of their high species diversity. It does seem reasonable that the existence of alternate prey and predator animals help stabilize populations. For instance, the raccoon eats the eggs of several different species of marsh birds, as well as crayfish, corn, young muskrats, and numerous other foods (Dorney, 1954). If one prey population fluctuates, the raccoon can still survive. Also, the fact that the predator has other things to eat prevents too heavy a load being put on one prey species. On the other hand, the presence of several different predator species helps control prey populations, that of the frog, for instance. Afrog can be eaten by a heron, a snake, a bittern, or an osprey, among others. If one predator population is low, others will keep frogs from becoming too abundant. Whittaker (1970) lists a number of changes that occur as succession proceeds. According to him, soil and microclimate are altered by the vegetation. Height and massiveness of vegetation and differentiation into strata(1ayers)increases. Productivity, or production of organic material per unit time, increases. The community becomes more efficient in utilizing its resources. Species diversity increases. Population changes become less pronounced. Stability increases. Finally, the climax is a steady state condition with energy loss balancing intake, materials loss balancing intake, and populations stable.

It is not clear that height and massiveness increase or that stratification of vegetation occurs in wetland succession. These are ideas based on a grassland-to-forest succession and may or may not apply elsewhere. Very little work has been done on wetlands in this respect. Many of these relationships stated above are the subject of much field study and analysis, and can be taken only tentatively in defense of wetland diversity. However, circumstantial evidence on the value of diversity is strong. In discussing the food web, frequent reference was made to the role of predators in controlling populations and to the loss of energy at each step in the chain. Thus, the predators can be used as indicator species. Although their absence from an ecosystem does not reveal the reason--were the individual predators removed or did something happen to the food chain farther down?--their presence indicates a healthy ecosystem. A diversity of vertebrate predators was therefore looked for in this study, but was not often found. One of the factors that makes for a rich species diversity in a natural system, and at the same time makes the system hard to understand, protect, and restore, is that the various species each have their own functional position, or niche. A niche is the sum of the relationships a species has with the rest of the system, what it eats, how, and when; what temperature it prefers; whether it is active by day or night; what plants it uses for cover, nesting; and so on. The theory is that species avoid direct competition by avoiding the use of the same resources in the same way at the same place and time. These niches might overlap partly, but not completely. From the standpoint of the system, the different species complement each other, and resources are probably utilized more efficiently than they could be by a single specles (Whittaker, 1970).

Another type of diversity which has received attention is structural diversity. An increase in structural diversity in forests was found to increase the bird species diversity (MacArthur and MacArthur, 1961). A somewhat different type of structural diversity occurs in wetlands. Different emergent species grow at different depths, have different heights, shapes, and rigidity. Shrubs and trees of course add to this diversity, so if they are not found in large uniform stands, they have value for animal species diversity. The relationship here is through the niche; swamp sparrows nest in shrubs and sedge tussocks, coots in emergent vegetation at water level, least bitterns above water level in rigid emergents, grebes on floating wet dead vegetation, and so on. Although we do not know of any work on structural diversity in wetlands, it is reasonable to assume that it has value.

An important concept related to that of structural diversity is that of edge. Many animal species utilize edgee, or boundaries between structurally different vegetation. In wetlands, these can be between two types of vegetation or between vegetation and water. A monotypic stand with a minimum amount of edge will support fewer nesting birds than vegetation with irregular, long edges. The name for this type of complexity'that has been used in this study is interspersion. Both the extent of vegetation- water interspersion and vegetation-vegetation interspersion have been noted in the field; we have generally found that these have suffered due to alteration for human use. Tm DISTURBED WqTLAND ECOSYSTEM

In our experience as well as that of many others, when ecosystems are tampered with, they are generally simplified. The development of ecological complexity takes time, and man is usually in a hurry. Ecological complexity increases because each species is reacting differently to different sets of influences. When man alters a system, he has one or two, certainly not more than half a dozen, objectives in mind. Side effects are necessarily ignored because they cannot be understood or because honoring them may interfere with the main objective.

POPULATION CHANGES Disturbance causes population fluctuations. Population changes may be due to direct causes, such as trapping, hunting, or removal of predators, or introduction of exotic animals and plants. When a naturally occurring species is entirely removed, the niche it filled becomes vacant. To some extent other species adjust their activities to compensate, but often the niche remains open. This is particularly true when predators are systematically removed, according to the policy favored by man over the centuries. The result is usually population fluctuations of other species.

An example of species removal can be seen with mink and muskrats. Mink are predators that control muskrats, but are often trapped for their fur. Then the muskrats may multiply, eat out the vegetation, and suffer a population crash from disease or lack of food or have to move elsewhere. The result is fluctuations in abundance of both muskrats and vegetation. However, the story does not end there, because muskrats are also trapped for their fur. A marsh where most of the muskrats have been removed tends toward uniform vegetation stands. Not only do muskrats eat emergent plant shoots and other underwater parts, they sculpture the bottom with their trails and deep areas around their houses. Grazing removes species from wet prairies. Most grazed areas in southern Wisconsin have been invaded by bluegrass, which will continue to resprout under grazing. Prairie grasses, which resprout only once or twice, will tolerate sporadic grazing, as by wild animals or very occasionally by cattle. Some deep-rooted prairie plants, such as dock (Silphium) can tolerate a few seasons of grazing. Some pioneer prairie plants will regrow from seed until the seed supply is used up. Prairie plants such as bergamot (Monarda fistulosa) appear not to be eaten by cattle.

Two other causes of species diversity loss are arbitrary abrupt changes in water level and the introduction of exotic species. Arbitrary changes in the water level destroys shoreline and shallow marsh niches, while causing wide fluctuations in populations. Exotic species, if aggressive, compete with and reduce the nuQers of native species. Both subjects are discussed further in this report. If current theories are correct, removing species reduces stability in many different ways. Some of these ways may yet be undiscovered, especially in wetlands, where relatively little work has been done. Each species not only participates in the food web, but also performs other functions to aid ecosystem stability and functioning. Further, from a human standpoint, a less diverse system is less intellectually and esthetically interesting.

RATE OF SUCCESSION

Disturbance also has an effect on the rate of succession. The change from sedge meadow to shrub carr is usually considered as a step forward in succession. Therefore, draining marshes and allowing shrubs to invade can be considered as accelerating succession. However, if indeed the sedge meadow is a climax, the invasion of shrubs represents alteration of the environment sufficiently to start off a new -successional trend. It is doubtful that the sedge meadow could ever build itself up to be as dry as most drained meadows now are. By watching shrub carrs over a long enough time, it can eventually be seen whether peat loss causes a return to sedge meadows. Then the carrs would be neither climax themselves nor succession toward a new, drie'r climax, but part of a cycle. When wetlands are partially flooded, succession is held back in the shallow marsh or deep marsh stage. Not enough is known at present to tell whether the succession is deep marsh- shallow marsh-sedge meadow, or bog mat-sedge meadow, or something else. Our deep marshes have been in much their present condition, cycling with water level and muskrat population changes, for thousands of years. Much work needs to be done with muck and peat core studies before wetland succession can be intelligently discussed. Meanwhile, human interference with water levels is changing the character of wetlands. In Dane County, there are sedge meadows which have been considered as candidates for flooding to increase the number of deep marshes. However, there is a real possibility that the consolidated sedge peat would float up. In Waunakee Marsh, for instance, one can walk through a bluejoint meadow, which is supposed by the plant community present to be relatively dry, and fall through a hole into deep water. The reason for this is that the peat is floating and the top surface is high and dry enough to support bluejoint grass. Whether natural or man-cauaed, this floating meadow probably resulted from a rise in the water table, perhaps a sudden one. A further point is that changing the water table not only affects the vegetation, but all of the species present. If changes are not too frequent or sudden, the system may develop complexity and stability in the new situation, with species to suit the new environment. Of course, this response to change in the physical environment happens many times in nature. The majar differences are the frequency of tampering by man and the extent and thoroughness of his influence.

INDICATOR SPECIES Since each species has certain envfronmental requirements and tolerances, it is possible to use species as indicators of condition. This concept was applied throughout the present study. Some indicator species are various shrubs and trees, especially when occurring in dense stands, uncommon or rare plant species, and exotic plant and animal species. Certain animal populations, such as those of muskrats, can be used to indicate changes in conditions. Shrubs have been discussed at length above. As far as available information indicates, shrubs in sedge meadows are disturbance indicators. In the same manner, trees are indicators of disturbance or change if found in numbers in a wetland. One can go out on a soil deposit, such as a power line or sewer berm, age the cottonwoods and willows, and estimate closely the date of the disturbance. Along the south edge of Hook Lake there is a ring of white birch trees which can probably be used to indicate former water level, and to estimate the interval since the level dropped (P1.32). Birch seedlings grow well on exposed damp soi1,asdo those of willow, aspen, and cottonwood.

The presence of rare plant species may indicate any of a number of conditions. If the plant in question is extremely sensitive to grazing, its presence in numbers locally means lack of grazing. Some species are generally rare now because the conditions they need, such as undisturbed fen or bog, are also rare. This may not have been the~casea century ago. Such plants may still be locally common. In some cases, a species is dying out slowly, and its presence indicates past conditions rather than present ones. In the event such a situation is suspected, other plant species distributions, water level, water quality, and so on must also be checked. There are also, of course, species which are rare regardless of the activities of man. They may be at the edge of their ranges, or dying out as entire species. In such cases, interest in their preservation is mainly a scientific one, to be able to learn more about their requirements and distribution while the opportunity lasts. Exotic species may be deliberately placed in an area or may invade due to successful competition with native species. The latter are especially a matter of concern, because they are aggressive, displace the natives, and may change the character of a community. Some examples of exotics are honeysuckles, buckthorns, reed canary grass, carp,.-.--. and pheasants. There are two species of buckthorn, Rhamnus franqula and Rhamnus cathartica, and one species of honeysuckle, Lonicera bella, which are exotic pests. All are planted in gardens as ornamentals, but disperse into the wild via birds carrying berries. They move into many types of disturbed areas, from exposed marl and peat to grazed woodlots. They are tolerant of the shade of the shrubs and trees which may already be present. Drained sedge meadows, already invaded by even-aged stands of willow and red-osier dogwood in much of Dane County, are susceptible to further invasion by these pests. Getting rid of them may be difficult. One way that looks promising is reflooding. Of course, reflooding would have a beneficial effect on drained wetlands in many other ways also. The problems in getting it done are economic and political, rather than biological or physical. Pulling shrubs out of peat is very difficult; the root network is extensive even though shallow, and peat does not provide a firm base to stand on. Deer and rabbits rarely eat the shoots of these exotics, although they do eat willow and red-osier dogwood, so the exotics gain a further advantage. Cutting may control the exotics, but they tend to resprout. Unless the new sprouts suffer from competition by sedges or grasses after cutting, the shrubs will rapidly regain their size. Poisoning of stumps may be necessary as a last resort especially if there is little labor available for cutting over a large area. Peat oxidation may control shrubs somewhat. However, reflooding is still vastly preferable.

A variety of Rhamnus frangula is being grown now as "tall hedge", and may gain popularity as a garden pldnt. It reswles chokecherry closely except for its buds and berries. Rhamnus cathartica resembles black cherry except for its buds. It characteristically has a pair of buds at the branch tip with a spine between them. The very sharp spines on the trunk make cutting difficult. It is capable ot shading out everything else, even honeysuckle and its own seedlings.

Honeysuckle has been used as a wildlife planting as well as a garden plant. Wildlife is apparently no longer attracted when stands become dense, however. It is difficult to control because it has spread so widely into pastured woodlots, and the seed source has become so extensive. Apparently it does not have many insect enemies, and of course importing insects to control it would be dangerous.

We consider reed canary grass (Pl. 33, along ditch edges) here as an exotic because, although it may grow wild in northern North America, it was not known in Wisconsin wetlands before introduction, and does not behave there as if it had evolved as part of the community. In 1933, reed canary grass (Phalaris arundinacea) was hailed as a valuable plant for Wisconsin lowlands

PLATE 34

FROM ASCS PHOTOS

PLATE 35 RECENTLY WIDE DITCH IN CHEROKEE MARSH

PLATE 36 MANMADE POND EDGE (J. SEEJAN)

v------(Holden and Albeit, 1933). It was considered an improvement over "wild marsh grasses" in terms of yield and feeding value. It was recommended for low areas which dry out slowly in spring, since spring flooding for days or even weeks will not kill it. It was also considered suitable for the mineral marsh border soils that must once have supported low prairie. However, it was not found suitable for bogs. Cutting and pasturing were both considered suitable uses. Directions for planting were given. Addition of potassium and phosphates were recommended for the high lime peats of southern Wisconsin. According to these authors, it could easily be removed, if desired, by plowing. White, MacVicar, and Nowosad (1948) noted that reed canary "in locations where it is particularly well adapted will become the dominant species." They considered it equal to brome and timothy for pasture, and equal to corn as a nutritive silage.

A recent paper on reed canary grass is that of Marten and Heath (1973). This was consulted because we have noticed many apparently abandoned stands of this grass in Dane County. The native vegetation has been widely destroyed due to planting of reed canary grass, yet the latter often appears unused. Reed canary grass has not become a leading forage grass as expected, and various reasons are given. It is apparently adequately digestible, but some find it lacks palatability. Attempts to document this finding have been contradictory. Marten and Eeath state that reed canary may be toxic, as some other grasses of the genus Phalaris are. In any case, this grass is frequently used for grassed waterways to control gullying, and for banks of ponds and channels. Its habit of making a sod by vegetative underground spreading makes it useful for erosion control, as it stops silt and keeps out woody plants. If properly used where stabilization of soil is necessary, rather than as a replacement for native wetland vegetation, reed canary grass should be beneficial. Some further remarks on the undesirability of reed canary grass in wetlands should be made. Due to the habit of forming a dense sod, once introduced, it probably displaces native sedges and grasses by its aggressiveness. Strains of reed canary suitable for agriculture have been developed, and these may account for the observed aggressiveness. It turns out to be harder than anticipated to remove. The sod must be broken with a marsh plow and buried completely. When used on ditch banks, it often moves into the waterway and clogs it. It does not provide good nesting and other cover for game (Loyster, peis. comrn. ) (but cf. Gates, 1970). A possible approach to removal involves covering the grass with black plastic to exclude light. This is cheaper than the operation of machinery and has the advantage of not disturbing the soil further. Recovery of water levels and closing of ditches is also useful for reed canary removal, as it does not tolerate as much inundation as native wetland sedges and grasses. Another well-known exotic species ie the carp (C rinus carpio) . These fish were not only purposely introdu-re was a nationwide program in 1879 to do so as one of the early missions of fish commissions. This was a familiar firh to our European ancestors, who did not know the fisheries dxvergity we have in this country (Threinen, pers. corn.). It uproots vegetation by its feeding and spawning activities in shallow water. Studies of exclosures (fenced-off areas) showed a definite increase in submerged vegetation where carp could not reach it (Tryon, 1954). Carp eat a wide variety of foods, including scums of algae on the surface. They do not compete much with the fish in deeper water, but do compete with waterfowl for plant food. The other, and perhaps major, concern over carp is that they stir up the bottom mud. Where this is organic, it settles fast, but the fine mineral silt now foundinso many lakes, marshes, and streams stays suspended. Carp do not need to see their food, so this does not hamper them. Other fish including game fish are at a disadvantage, however. Recreational users of the waterways find the constantly muddy water annoying. Carp easily get out of balance with other fish by better winter survival in waters made shallow by siltation and by hiding in

- - muddy-. water-- from-- predatory birds and fish. -- For many years attempts were made to control carp by harvesting. This is not an elimination procedure, and must be continued in- definitely. In some areas, this is adequate for control, and carp are somewhat used as a human food source. The expected desire for this fish in this country appears not to have material- ized, and we are saddled with a pest. The recent development of the fish poison antimycin has been hailed by managers as a relief from the carp problem. However, its present application to entire watersheds results in almost complete loss of native fish in those areas. Invertebrates appear to recover, but fish must be re- stocked. No attempt has been made to assess the cost from an ecosystem standpoint. An approach that might be considered further is use of fish flour from carp as a protein source for people and for stock. Ironically, another exotic fish, the white amur, is now being considered for introduction as a vegetation control. It is already found in the Mississippi watershed, but is not expected to reproduce naturally (Threinen, pers. corn.). There is not yet enough general understanding of the role of exotics to cause people to be reluctant to introduce them.

Ring-necked pheasants are common in drained wetlands and wetland edges in Dane County, as elsewhere in southern Wisconsin in similar habitat. They are continually released for hunting purposes. Although pheasants extensively use sedge meadows, shallow marshes, and,in winter, deep marshes for cover, it is doubtful that a niche exists for them in the warmer seasons in deeper undrained marshes. ..- There has been a significant decline in the Wisconsin pheasant population over the last 40 years due to loss of habitat. Since this is a valuable game species whose replacement by pen-reared birds cannot make up for the hunting demand (Gates, 1970), the Department of Natural Resources is purchasing land under a scattered wetlands program to preserve nesting cover. This is especially important now that the federal government has discontinued the Soil Bank Program.

We have not found any direct effects of pheasant populations on the wetland ecosystem. However, pheasant management may have an effect. Gates (1970) notes that nesting hens prefer stands of forbs or reed canary grass, or mixtures of these with sedges, rather than stands of sedge or shorter grasses. The criterion seems to be tall forbs or grasses rather than certain species. Our concern is that reed canary grass not be planted for cover, but that native species with tall, early-season cover be emphasized. CULTURAL INFLUENCES ON WETLANDS

Human or cultural influences on wetlands are to be viewed against the background of geology, soils, hydrology, water quality, and biological systems. These cultural influences do not always result in complete destruction of wetlands; in our survey, a large number of partly degraded areas were found. Sometimes the goal of human activity is the destruction of a wetland per se, but usually it is used for an incompatible purpose such as farming or high intensity recreation. Quite often degradation is incidental to another project, or even accidental.

Total destruction is, of course, not worth discussing except to note that benefits such as protection of water quality and provision of wildlife habitat are lost with the wetland (Pl. 34). Since the wetland in question is often part of a group, as in northwestern Dane County or the Yahara River valley, the value of the whole is affected. The remaining wetlands become more valuable in a sense because they are increasingly scarce, but the total wildlife use and the overall water quality in the area decline.

PARTIAL DRAINAGE

The major impact of man on wetlands is the result of trying to convert them into either dry land or lakes. Partial drainage, very common in Dane County, as elsewhere in southern Wisconsin, results from attempts to farm either low, wet adjacent areas or the wetlands themselves. Farming in such wet areas is often hampered by spring flooding, short growing seasons due to frequent frosts,and loss of peat soil. In many cases, farming was started during the drought of the 19301s, and despite drainage attempts, has not been successful since. However, where wetlands were shallow and drainage systems are efficient, farming has been successful. The effects of partial drainage of wetlands include nuisance invasions of nettle, ragweed, and trees or shrubs, and reduced water quality at the outlet. Unfortunately, it is also often considered necessary to ditch sedge meadows and fens heavily to get the water away from adjacent farm fields, The wetland suffers even though not directly used. In some cases, as in the Deans- ville Marsh area, actual lowland crops are grown. However, eventually the peat oxidizes to the point where even sod and mint farms are no longer feasible. At that point, such areas could be reflooded at least enough to re-establish a sedge community. For further discussion of this, see the management suggestions. DREDGING

Wetlands are often deepened locally by dredging. Usually the purpose is either to provide access for boats to points along the shore or to remove undesirable sediment. In many cases in southern Wisconsin, cottage or housing development along a shoreline has meant dredging of a deep marsh or even removal of peat from a bog or sedge meadow (Pl. 35). The results of such channelization include formation of berms or spoilbanks with attendant bank erosion and shrub and tree invasion, decline in water quality from leaching, destruction of habitat, interference of movement of animals to and from the shore, and disturbance due to passing boats (Fig. i4B) . It has been a common practice, as noted several times during this study, to dig holes in peat to make ponds. Again, the spoil is often dumped nearby and becomes a source for nutrient leaching. The sides of the holes are often too steep to support much emergent vegetation. An alternative to dredging _holes is blasting. The Department of Natural Resources (DNR) has found that blasted holes are too small and predator-prone for waterfowl nesting, and are used by wildlife only as watering areas. The DNR1s Environmental Policy Division now prohibits blasting holes or other activities on DNR lands that spread deposits of peat or muck on the surface. There is no control over dredging and blasting of holes by private landowners, but the DNR now discourages it (Loyster, Knitter, pers. comms. ) . The digging out of springs is also common practice, so much so that in some areas it is hard to find unaltered ones. Dane County is fortunate in having several in good condition or at least restorable. Although there are many closed-over springs and seepages where wildlife use may improve somewhat if a pond is dug, undisturbed springs with a large volume of flow tend to stay open. The role of undisturbed springs in peat formation is an area of study that needs attention. Further, disturbance of springs and seepages destroys important plant communities and lessens esthetic values. Natural lake and marsh bottoms are uneven in depth and vary in soil characteristics. Sand, marl, muck, and peat can be found locally. An effect of this variation is to create microhabitats for aquatic plants and for various animals. Dredging in deep marshes tends to destroy this diversity which has developed over centuries. We have not seen adequate docu- mentation of such effects. Generally, deepening by dredging is a consequence of a need for silt removal. The silt overburden itself is a detriment to the wetland system, but its removal by use of heavy machinery can have drastic consequences. A far better course of action is to emphasize keeping soil on the upland. FIGURE 14 SHORELINES AND WETLAND HEALTH

DUCK, SNAKE, TURTLE NESTS FEEDING FROGS, SALAMANDERS, ETC. NATURAL CONDITION: \ w-UNFARHED BUFFER STRIP

OCCASIONAL SHRUBS NO DITCHES

DOES NOT ST1 R UP FOR LONG. CRAYFISH, DRAGONFLIES, SHRIMP. FISH NESTS

OXIDIZING PEAT MOST LETS RURAL: ADJACENT LANDS DITCHED, GRAZED; 3 FATES OF MEADOW OR FEN HAB ITAT LEACH OUT INTO SHORELINE DEEPENED FOR LAGOONING (A-B-c): GONE WATERS S WETLANDS; IN ALL CASES PEAT FATE A: ' 0 I SAPPEARS DITCH ING DCWt:STREAK LOW CROPLAND DITCHED, ALLOWS SUMMER LOW-LOWS DRAINED FOR EARLIER WORKING MUDDY WATER NUISANCE PLANTS

DREDGING OF SHORE DRAINED HOWING MEADOW DRAINED HEADOU PASTURED, MAKES ABRUPT DROPOFF LOSES UPPER PEAT IN THEN ABANDONED, INVADED PEAT FIRE, BECOHES BY SHRUBS 5 TREES WHICH DEVOID OF LIFE, ERODES BACK WlTH WAVE AND ICE NETTLE AND SEDGE KILL SUN-LOVING SEDGES ACTION DWELL l NG AN I~LS CONTOUR COVER PATCH. AND GRASSES THAT UKE PEAT, AH0 PLANTS SO PEAT OXIDATION ACCELERA~

URBAN: RESIDENTIAL OR COMMERCIAL

STILL MORE HABITAT GONE WEEDS r WEED TREES wra INVADE DRY,UNUSED FILL LAWN *TAW,#@ 6.iu WIDELY FLUCTUATING HUDDY r - ---- EUTROPHIC WATER WlTH ------4----- T \ I NTEWNT WATER IMPOUNDMENT

A second way to make a wetland deeper is to impound water. This is not possible everywhere, as many southern Wisconsin wetlands are isolated potholes. Flooding does have the advantage of not destroying the character of the bottom, but whether or not it benefits a wetland in general is a complex matter. Flooding enough to make an open lake of course destroys the emergent vegetation and disrupts the wetland ecosystem entirely. Where there are many wetlands and few lakes, which is not the case in Dane County, this may be desirable.

Flooding can be quite beneficial , especially in restoring a previously drained wetland. Horicon Marsh is the classic example. Various other impoundment rojects have been undertaken around the state by the Department OF Natural Resources, especially for waterfowl purposes, but only one in Dane County. It is becoming more usual to consider the entire ecosystem when planning management, which is an approach that benefits not only the target species but the rest of the wetland as well. A common problem, as discassed in several parts of this report, is the excessive growth of algae (Pl. 2) or waterweeds (aquatic macrophytes) due to high nutrient levels in the water, usually caused by poor upland management practices. By retarding flow, impoundment may intensify nuisance plant growth.

A common practice in impounded wetlands is the drawing down of the water level suddenly and arbitrarily (drawdown). The sudden- ness and arbitrariness is with respect to natural processes, which .tend to be slow and seasonal. The drawdown may be employed for any of a number of reasons, for rough fish control (current Horicon Marsh project, part of Upper Rock River carp eradication project), enhancement of duck food production, compaction of bottom sedi- nents, or, if done in winter, eradication of waterweeds (Beard, 1969). Usually it is done late enough in the summer to miss the breeding season, or in fall or winter. However, some marsh birds feed their young aquatic foods into August, and these young may be lost. A late summer drawdown may also expose molting ducks to predators, as they go through a brief flightless period. Further, a drawing down to a very low level encourages growth of emergent plants, which then may die when the water is returned to its usual level (see discussion of cattail die-off in Mathiak, 1971). Since leaching of peat soils occurs rapidly after their exposure to air, there may be considerable nutrient addition to the watershed during a drawdown. Under natural circumstances, wetlands experience a wide range of water levels from wet years to dry ones. There are shifts in vegetation as a result. However, there are rarely situations where water level changes are as rapid and frequent as with drawdowns. It may become difficult for the vegetation to approach natural conditions of interspersion and diversity with frequent rapid water level changes. Rapidly growing pioneer plants will be favored. Some of these are water- f~wlfoods, but others are weedy. On the other hand, the results of' keeping the water level too constant need further investigation, as this, too, might discourage diversity in some cases. FILLING

When a wetland is partially filled, it is usually done from the edge toward the center. This is generally done slowly by dumping fill as it becomes available (Pl. 28). Thus, the slope from upland through shallow water to deep marsh is wiped out, along with the characteristic plant communities (Pl. 36). See Figure 14 for a summary of effects of shoreline loss. Often this effect is increased by dredging the center to make a lagoon, as at Vilas Park in adi is on. The natural shallow edge is the link between land and water, and as such serves many functions. Turtles go ashore (Pl. 37) and frogs enter the water to lay eggs. In fact, the breeding of certain frogs requires-. -very - - shallow water (P1.38). Many types of birds feed in shallow water or on exposed mud. Relatively shallow areas support the emergent growth such as cattail used by most marsh birds to support and conceal their nests. Narrow strips of cattail parallel to the shore are pre- ferred by the least bittern for nest sites (Pl. 18), for instance. Cattail grows out by a floating root structuretoa water depth of 3 to 4 feet, and this is not too deep to discourage filling operations. As filling proceeds, the food web is simplified and the ecosystem made unstable. Esthetic values are destroyed. The most pathetic example we have seen of part of a high quality marsh continuing to function as it was progressively filled, with the goal of total destruction, is to be found at the Atkinson Marsh in Green Bay. There is as yet no law to prevent this happening in Dane County. The above remarks on partial filling do not, in general, pertain to sedge meadows, as deep peat does not provide a firm base for fill. However, some have been filled anyway, such as the Dane County Fairgrounds (Pl. 39). Current laws prevent bringing material into designated floodplains and dumping garbage near water or in lowlands, but otherwise filling is not discouraged by law.

POLLUTION AND SILTATION Wetlands are not always filled by direct action. One of the proposed uses of ~unn's Marsh, south of Madison, is as an urban retention basin. The items to be retained include peak water flows during floods, silt, salt from the streets, oil from paving, and whatever else is in transit from the city to the lakes. Considerable silt has already entered this marsh. Some flooding can be tolerated, so long as it does not occur during the nesting season and does not cause frequent cattail die- backs, but the other factors are as degrading to the marsh as to the lakes. Dunn's Marsh is exhibiting an increase in algal growth in the last few years, possibly from lawn fertilizers improperly applied. Silt is a definite threat for several reasons. It could be argued that a silt deposit on the bottom would seal off unwanted nutrients, but if it does that it will also seal off the habitat of the benthic (bottom) organisms (Ellis, 1936) . However, since silt (inorganic material capable of being carried by runoff) is very fine, the least agitation of the water, such as by wind or animals, will stir it up. .An experiment of ours

showed that an organic bottom sediment, when shaken in a jar, will settle entirely in about fifteen minutes, whereas silt will take two or three days to eettle. Marsh waters are rarely still that long, certainly not if carp are preeent. The euspended silt cuts down light penetration and may interfere with the respiration of invertebrates and fish. Where a lot of silt enters a marsh, one usually finds both a silt deposit, sometimes several inches deep, and suspended silt (Pls. 1, 40). This, of course, accelerates the filling of the marsh. There is a vegetation change also, since plants such as bur reed and arrowhead perfer or tolerate silt at the expense of cattails and other plants-- -- that provide firm nest supports. -. - - Highway construction can be disruptive to a wetland whether or not the road actually crosses it. If it does, vegetation is destroyed, water flow patterns may be altered, water levels may be changed, water quality suffers from salt and oil runoff and from peat distrubance, and wildlife is disturbed. The results of construction vary from one wetland to another. Often new or improved roads bring other types of development, which in turn increase pressure on the watershed. Since one type of disturbance tends to lead to another, the final result may be the sort of degradation of esthetic values that leads people to think wetlands are eyesores. This attitude of course worsens the whole situation.

To the extent that they obliterate spring flow, locally block ground water movement, accelerate or concentrate surface runoff, or expose peat to air, road building and subsequent development in the watershed will shift wetland conditi>nstoward being more eutrophic. A serious type of disturbance in a watershed from upland road building is due to erosion of large amounts of bare subsoil 1 4 In 1968-69, the extension of South Park Street (U. S. route 14 to Oregon) was rebuilt. A large area of subsoil was exposed on a hillside above Nine Springs Creek, thus en- dangering water quality in that entire wetland system downstream from that point. As far as we know, no measurements of erosion were made. A wet spring such as the one of 1973, with attendant runoff, would have caused significant deterioration of the creek area.

CHEMICAL ALTERAT ION Chemical alteration of water quality in wetlands may be subtle or obvious, intentional or accidental. The addition of nutrients to the water, usually by runoff from fertile areas, has been discussed in detail above. Other unintentional chemical sources are from industry, from urban runoff (e. g. salt) , and from agricultural runoff (e.g. pesticides). Dane County does not have enough heavy industry for this to create a serious problem, although local effects have occurred from time to time. A former plastics factory apparently did discharge materials toward Lake Mendota. Oil from filling stations, entering storm sewers, has been a problem in the Lake Wingra watershed, although it is probably not concentrated enough to be a serious threat. In May, 1969, an oil slick appeared on Dunn's Marsh where a storm sewer had brought it after a paving project in a shopping center (PI. 31). When material collects in storm sewers and is not removed before subsequent rainstorms, it does eventually wash into the lakes and wetlands. The City of Madison apparently was not equipped to remove the oil slick. An oily surface layer can foul the breathing apparatus of invertebrates, cut down on oxygen exchange between water and atmosphere, cover the feathers of swimming birds, may be toxic, and is unsightly and smelly. Some chemical alteration is done purposely. The most common examples are the use of fish toxicants and of herbicides. Fish toxicants are poisons which, when used in a concentration suf- ficient to kill the rough fish which are to be eliminated, necessarily kill all other fish also. The most sophisticated and least dangerous product so far developed is antimycin. Individual carp can be killed with this since they cannot detect and avoid it. However, the usual method of application is to treat an entire lake or even an entire watershed, with the goal of removing as many rough fish (usually carp) as possible. This necessitates restocking with fish, usually not the original genetic stock and often not the original group of species. Typically not enough study of the locality is made to seriously attempt to restore a desirable balance of populations of the various species. Restocking with a balanced population may be impossiblej certainly our understanding of population dynamics is at present inadequate for this. Quite often exotic species are stocked. The effects oftoxicants on the ecosystem as a whole are far from understood,and are a matter of great controversy. The interaction of carp, water quality, and waterweeds is discussed above; The use of herbicides to control waterweeds is hotly debated in Dane County.

LESSER DISTURBANCES

Other forms of wetland disturbance, although serious, are not as severe. Some of these are burning, vegetation disturbance such as haying, timbering, plowing, and pasturing, and high intensity recreation. Burning has been discussed above. Accidental burns may not be more serious than the earlier natural ones as long as the water table is high enough. However, as we saw, burning of drained peat lands can be very destructive. It has been our impression that this is often done on purpose, although the presence of dry peat makes accidental fire more likely. Haying is perhaps the least destructive of wetland vegetation disturbances. It is no longer practiced with anything like the frequency with which it once was. The only example in Dane County we know of is a small meadow of native vegetation along the Wisconsin River. As of 1908, the hay in the Madison Fair- grounds area was typically cut in August for fodder or in the winter for bedding and packing ice (Stout, 1912). Whatever effects on the species composition there may have been were too subtle to discover without detailed comparison of hayed and aon-hayed areas. This was not done. Stout found a good species diversity and vigorous growth despite haying. This practice did remove nutrients from the system, but more were probably mobilized from the peat. In a cattail marsh during the first summer after a winter mowing, growth is more dense probably due to removal of competing dead stalks, except where plants have died out due to drowning of cut stems (field observation). Timbering, that is, removal of shrubs and trees, was often practiced along with haying to make more fodder available. This probably amounted to nothing more than setting back the cycling of vegetation. That is, if the area were left alone after haying stopped (which few were), the shrubs and trees should eventually have reinvaded. Tamaracks were often removed for use as fence- posts, since the wood does not decay rapidly. Even if all of these trees are removed, they should be able to return if a seed source is available and conditions for growth are suitable. However, most such bogs were further disturbed, often drained and all the vegetation removed.

Plowing a wetland need not in itself be irreversibly damaging. The natural vegetation should be capable of re-establishing itself in the future. However, plowing usually can be accomplished only after drainage, with all of its attendant destruction. A considerable seed source of exotic plants now exists, which also hinders the return of native species. The oxidation of the peat also tends to favor a different plant community. Careful reflooding might be successful in restoration, but needs further study.

Pasturing of sedge meadows is common in Dane County. Grazing has a very noticeable effect on the appearance and structure of a tussock (Carex stricta) meadow (Pl. 42) . Costello found that cattle and horses eat the sedges only when grass in the area is depleted. While the tussocks themselves may survive light grazing, bluegrass invades between them and along with the grazing prevents the formation of new tussocks by vegetative propagation. When grazing is intensive, soil is exposed, the soil water is depleted, and succession to bluegrass is faster. Weeds invade after grazing stops (Costello, 1936). Shrub invasion is common in abandoned, low farmlands such as those purchased by the Department of Natural Resources, presumably because of less competing ground cover and a drier surface. In our own observations, we found that native species were sup- pressed whereas the humpy texture of the tussock meadow was accentuated by trampling (Pl. 42). Where the meadow is next to a stream or marsh, the cattle usually have access to the water and trample the banks heavily. Such a situation is a common sight throughout southern Wisconsin, and contributes to silt and nutrient loads in streams, wetlands, and lakes (Pl. 43). Use of wetlands for recreation may or may not be destructive. The highest intensity uses involve such approaches as flooding for boating and lagoon-making'forpark use. This results in the type of destruction already discussed. The rationale has been to make something easily identifiable as useful, such as open water or dry land, rather than to consider the existing values of the wetland. This approach has in general made the preservation of natural areas difficult, affecting wetlands less than uplands only insofar as they have been difficult to manipulate. However, there are large numbers of people who prefer outdoor experience in natural areas.

The five most common recreational uses are hunting, fishing, trapping, snowmobiling, and nature study. The last of these is usually undertaken by a very few people who are anxious not to disturb the areas they visit, and needs no further discussion in this connection. The actual process of hunting, fishing, or trapping does little or no harm. The only exception may be where certain species are depleted or removed. In fact, many wetlands are protected by being publicly or privately purchased with hunting money. In general, the management for hunting and fishing exerts more change on wetlands than do the actual recreational activities Snowmobiling in natural areas in general destroys vegetation and disturbs wildlife (P1.44). In wetlands travel on open ice will not disturb the vegetation, and following an established path will minimize such disturbance. Since many of the Dane County wetlands contain springs, snowmobiling in these areas, as in South Waubesa Wetlands or Waunakee Marsh, for instance, can be extremely dangerous. The summer equivalent of the snow- mobile, the all-terrain vehicle, is fortunately rare in Wisconsin. Use of these machines during the growing season is highly destructive to vegetation and reproducing birds and animals, and should be prohibited.in all natural areas. Indirect cultural influences on wetlands include: (1) effects of human activity on the balance of surface and ground water, including spring destruction and lowering of ground water by drainage, wells, and possibly by runoff acceleration; (2) effects of human activity on water quality, including agricultural practices in watersheds (P1.45), exposure of bare soil during building construction, runoff and percolation from septic system, sanitary and storm sewers, and urban runoff; (3) destruction of buffer zones (P1.46); and (4) effects of increasing population density on wildlife, esthetics, and public attitudes.

PLATE 45 EROSION IN CORNFIELD IF. R. JONES)

PLATE 46 APflRTMEPTTS O?l Durn " S MARSH BUFFER ZONE

------. - --

PLATE 47 GRADE SCHQOL CLASS

r MANAGEMENT, MAINTENANCE, AND PROTECTION

In this section, techniques for planning and managing for wetland maintenance and protection are diecuesed, first from the general standpoint, then with respect to individual wetland types and situations. The basic discussion in previous sections is intended to be a background for these suggestions.

GROUND WATER - No wetland can survive if it is dependent on a ground water supply which is dwindling due to human land use. This is of great concern in Dane County. After identifying which wetlands to concentrate protection efforts on, using evaluation methods such as those in this survey, the first step is to study their hydrologic relationships. In many cases, money Eor further research will be needed. Ifa wetland is a discharge area, as most are, the corresponding recharge area must be located and protected sufficiently to insure a continuing water supply. Depending on the volume of water stored in the aquifer and its rate of recharge, well density, locations, and pumpage rates can be determined so as not to endanger the wetland; Discbarge areas, springs and seepages, must be located and protected from blockage by fill, road building, and so on.

When planning building construction, recharge areas must be studied to determine whether land use changes will significantly decrease the recharge rate, for the benefit of all users of ground water as well as for wetland protection. At the same time, runoff must be controlled. Ground water stability, surface runoff volume, water quality, and erosion control are all interconnected. Erosion and runoff abatement can be practiced in housing development areas in several ways: minimizing paving, building two-story buildings with smaller roof areas, providing ground water recharge areas where soil conditions do not allow rapid percolation, using steep hillsides for low density development with minimum soil exposure for minimum time intervals, placing temporary cover over bare soils, keeping slopes in natural vegetation, using catchment areas where necessary, and providing buffer zones between runoff sources and wetlands or waterways. The knowledge and technology exist, but the concern has only begun to develop. As more citizens realize the extent of the problem, it should become possible to enact legislation to improve the situation. Certainly a legal concept is needed whereby one is responsible for down-watershed damage caused by erosion and runoff. We urge support of Soil Conservation Service efforts to promote a sediment control ordinance. - The protection of springs themselves is needed in Dane County. Springs have both scientific and esthetic value, yet the prevailing idea is to "improve" them by digging them out into ponds. Plants and animals in the water near the spring head may be displaced, and berms may be formed which leach nutrients into the water. Further, these berms may be unstable, may allow invasion by exotics, and often have steep sides which hamper wildlife access to the water's edge. Meanwhile, species diversity and scientific information are lost; Although most of these changes would not be drastic for the wetland, there seems to be no clear evidence of gain from digging out springs. With a diversity of wetland habitats available, it should not be necessary to alter a spring to attract waterfowl. Not every wetland needs to have large numbers of waterfowl so long as there are many which do. The trick is to locate the appropriate ones to improve. Often springs are used as stock watering areas, which usually means trampling and erosion of stream banks and a deterioration in water quality. One of the rationales which concerns us is that a natural feature, such as a spring, needs to be altered just to appear "nicern to the eye of man. We hope for a continuing trend toward understanding and appreciating such features left as they are.

UPLAND MANAGEMENT -. - Runoff abatement in agricultural lands has been thoroughly studied from the point of view of soil conservation, since running water can carry tremendous quantities of soil with it. Suggestions for runoff and erosion control can be found in any good soil conservation reference, but to emphasize the problem we consider a few here. A common problem in Dane County is that of leaving fields bare through the winter. This is helpful to cut down time before spring planting, but it is not without cost. Rain falling on frozen soil does not percolate, but runs off rapidly, often carrying manure and surface soil with it. Lake Mendota has been shown to suffer from this problem. The large amount of corn grown in this area means much bare soil under the plants which gullies and leads to silt deposits during heavy rains (P1. 45). ~n effort needs to be made to maintain a buffer strip between the cornfield and the waterways. The new concept of minimum (no) tillage is important. With this technique, one eliminates plowing. It is possible to leave stubble on the field over the winter, then instead of plowing, disking, and harrowing, one can plant in one operation. Soil structure is improved, soil is protected against wind and water erosion, and soil moisture is preserved (Foster, 1973) . On many steep dry hillsides in Dane County, grazing results% in extremely close cropping of the vegetative cover. This damages the cover and makes erosion likely as well as increasing runoff. Stock are often allowed free access to stream banks for watering purposes. Without any protective devices, the banks are stripped of vegetation and trampled down. Sometimes feedlots even include stream banks. This is such a common and damaging practice in southern Wisconsin, and so easily preventable, that it deserves emphasis. The only step which seems available for suggestion is to mount a determined public education effort. The Soil Conservation Service has been active for years, yet much still needs to be done. Once the silt is on its way toward the wetlands, all still is not lost. Buffer zones of natural vegetation, flat grassed silt deposit areas, and catchment ponds can be used. In some wetlands covered in the present survey, specific areas are designated for such buffers. Another approach is to let silt enter a shallow pond with emergent vegetation. Eddying around the plant stems slows the current and causes the silt to drop out. Eventually, however, the silt may have to be removed. Such treatment of a pond is hard on living organisms and is not recommended for quality wetlands which are to be protected. If necessary, a new pond for silt catchment may be constructed between the source and the wetland. Special attention is needed where runoff enters a buffer area so it is spread out and does not cut channels or gullies through the buffer--be it forest, field, meadow, or shallow pond.

NUTRIENT ABATEMENT Much of what has been said above also applies to nutrient inflow abatement. Agricultural runoff carries fertilizers and manure and urban runoff carries a variety of things including leachate from leaves in gutters. By controlling these sources, nutrients can also be controlled. Ground water protection also helps, since phosphates are generally taken up by the soil and don't reach the ground water. Buffer zones and retention basins tend to be helpful only if the nutrients can be incorporated into organic material there and deposited.

Sewage is an important consideration which needs attention where septic systems are concentrated near lakes. Tertiary sewage treatment that removes nutrients could be helpful to the Badfish Creek area. The idea of using partly treated nutrient-rich sewage effluent, already rendered safe from infectious material, for upland fertilization is an excellent one that deserves more consideration in Dane County. In this way nutrients can be recycled. At present agricultural fertilization represents an influx of materials into the local ecosystem. It is pretty difficult to maintain good water quality in the face of this. Those nutrients which do leave the local system are carried down the rivers and compound problems elsewhere. A similar technique which has been useful for small isolated lakes is to pump the nutrient-rich water onto the surrounding land and let it flow back. This approach might be applicable to landlocked Crystal Lake, along with control of septic systems. WATER CYCLES Since wetland plants and animals, are adapted for natural water cycles, it is essential to maintain or at least simulate them. Watershed runoff patterns should be studied and controlled. Further wetland drainage must not be permitted in Dane County. Not only does it destroy the most important values within the wetland itself, often to no one's gain, but it has a degrading influence on the environment in general. Lowland soils are difficult to crop because they oxidize, are frost pockets, and are subject to flooding in spring and in wet years. Even lowland crops such as mint can be grown for only a few years. '2he water table is lowered locally, water quality deteriorates, and downstream floods become more frequent. Although itmay be

difficult-- to brinq such areas back to anything like their original condition, we urge a limited reflooding of as many such areas as possible. This usmeans purchase of adjacent low crop- lands. but the watershed protection and wildlife values alone make it worthwhile. ~ocaimoney for water control might be combined with the Department of Natural Resources Scattered Wetlands funds. Such a small portion of our wetland heritage now exists, a fact repeatedly brought home to us during this survey, that we find an absolute halt to drainage essential.

LAND USE Land use control is essential. There must be legal means if necessary to alleviate tax loads on conservation land, relieve the land from being the major source of needed tax revenue, establish buffer zones, control development patterns, protect slopes, and control the placement of roads and power, sewer, and gas lines, to name a few items. The proposed power line enlargement at Goose Lake is an example. The above is nothing but a repetition of solutions needed for general land use problems. Wetlands are affected as much as if not more than other environmental assets. We wish to introduce two further concepts, "graded density development" andl'skyline zoning". The usual practice without land use controls is to maximize use of those environmental amenities most sought after by the public, usually destroying them in the process. Lakes are ringed with cottages with no concern for eutrophication or even for esthetic values. Wetlands are filled, dredged, and so on, to maximize real estate profits (Fig. 15). "Graded density development" reverses this approach (Fig. 16). Each wetland or other conservation area, along with its buffer zone, is declared off limits for construction. Next comes a zone of limited allowed construction with strict attention paid to watershed protection and esthetic values. Farther away is a zone of moderate density construction, except for steep hillsides. Finally, farthest away, is the maximum density zone. In addition, a natural, no-construction corridor is chosen to . connect adjacent conservation areas, using natural, not political or economic, values for its location. To the planner, this may sound like Utopia, but unless a serious attempt is made to consider long-term public values, the alternative will be successive degradation of the landscape. The relationship between adequate and appropriate land use and the increase in human population needs to be mentioned here. Dense developments and high land prices go hand in hand with population pressure. If people are packed too densely into small regions to spare agricultural, wildlife, and esthetic values elsewhere, the local hydrologic situation deteriorates and the people suffer psychologically IMAGINARY MARSH A Map Key

Dense waterweeds

kmergent vegetation, deep and shallow marsh

Sedge meadow :- $2: ,merge,, vegetation, indicators of silt deposit

Disturbance vegetation, asters, reed canary grass, drained but not cultivated

Disturbance vegetation where sometimes cultivated

,)L Fill

Pasture

Cultivated

W.Spring

IMAGINARY MARSH A

SHOWING COMMON WETLAND MISUSES

Ponded spring, for use in watering cattle in high-use pasture. Stream banks trampled and eroded. Grazed sedge meadow. Cultivated in drier years, nettle and ragweed in wetter years.

Asters and reed canary grass on topsoil deposited in marsh from eroding field; reed canary grass on ditch berms.

Shallow marsh, especially bur reed and arrowhead, on silt. Dense water weeds, due to high fertility in water. Former "conservation pond1' at spring, now receives storm water from development. Cattle watering pond dug at marsh edge. Grazed woodlot. Hilltop zoned for dense single-family dwellings. Increased overland runoff and decreased spring flow (caused by well drilling and runoff) may be expected. Storm sewer pipes.

Shallow marsh vegetation on silt at pipe outlet. Dredge-fill line. Developing gully, resulting from apartment construction uphill. "Braided stream" developing where subsoil is deposited. Note delta developing where runoff enters marsh. Zoned for apartments. Extensive erosion may be expected on steep hills during construction. Concrete troughs surrounded by grass, in locations of former gullies. Zoned commercial.

Factory with toxic effluent entering stream. IMAGINARY MARSH B Map Key

Emergent 'vegeta1:ion, deep and shallow marsh, zoned conservancy

Sedge meadow, zoned conservancy

Additional conservancy zoning

cultivated 6.0- .: t.,- Fenc.e line protecting spring and streams

@ Spring

IMAGINARY MARSH B

SHOWING PROPER LAND USE AND ZONING

1) Springhead with sedge meadow, fenced off from use by cattle.

2) Pasture, number of animals adjusted to carrying capacity.

3) Watering trough with wa.ter source from permanent stream. Effluent does not re-enter stream. 4) Gravelled cattle crossing, for streambed protection.

5) Cultivated area, with contour strip cropping, possibly also minimum tillage practices. Soil is not left bare and manure is not spread in winter.

6) Conservancy z'oning, natural vegetation or grasses planted for mowing. Natural vegetation is left in spring and stream areas.

7) Open water area with several species of submerged plants, but no "water weed" problem. 8) Natural spring. surrounded by emergent vegetation.

9) Hiking and nature trail. Trail easement is planned into developed area; most of trail is in conservancy zone. Wildlife observation point and foot bridges are included.

10) Optional boardwalk and wildlife observation point.

11) Zoned for single-family residences, but not as dense as that found in suburban regions. Pavement and ro.of areas are minimized, construction on steep slopes is minimized, erosion controls are strict, wells are drilled away from spring recharge area.

12) Conservancy zoning protects intermittent streams. Native grasses may be planted here to control water flow, prevent gullying. 13) Marsh outlet, flow pattern through emergent vegetation.

14) Zoned agricultural or low-density,single-family residences. 15) Conservancy zon$ng, with natural vegetation retained or restored. Entire marsh is also zoned conservancy.

16) Higher density construction is kept at a greater distance from marsh. as well. If they are allowed to spread out instead, important land uses are lost and wildlife suffers. The only viable solution is a limit to the population. The above plan is intended to handle development should it occur, not to encourage it. The present floodplain zoning law is a step in the right direction, but an overall approach is still sorely needed. "Skyline zoning" is a special case of the above. Dane County has several marshes and ponds and a bog in kettle holes. The rims of these kettles are relatively small and steep and form a nearby skyline at the edge of a very small watershed. At Hook Lake, the best example, it is possible to stand in the middle and see very little of the surrounding countryside. Within this near skyline no further construction at all should be permitted. Since the area is so small, this is economically reasonable. Without such zoning, dense development could occur along the lake edge, causing ground water depletion, water quality deterioration, wildlife disturbance, vegetation disturbance, and esthetic deterioration.

A major land use control needed in Dane County as well as the rest of Wisconsin is prohibition of wetland filling. This is probably the second most serious cause of wetland loss. The outstanding Dane County examples are the filling of the County Fairgrounds wetland and the north edge of Upper Mud Lake in Monona. This is not a new idea in wetland protection, but one which needs repeated emphasis. Partial filling can sometimes be almost as detrimental. Legal protection against alteration of natural shorelines is needed, one of the most difficult aspects apparently being legal definition of the usual high water line (Posekany , pers. comrn. ) .

RESTORATION One of the most important concepts is that of restoration. It is unfortunate that, due to our economic system, money is available for destruction of the environment for short-term gain but not usually for restoration for the public good. Prairie restoration has been popular in much of the Midwest, but has a long way to go before it can be done on any kind of large scale. Wetland restoration as such is a virtually untouched but exciting field. The techniques to be explored depend on the type of wetland involved.

blEED FOR ECOSYSTEM APPROACH IN MANAGEMENT Deep marshes have been restored for waterfowl purposes, or in some cases, created where no marsh had been before. This is done by placing a dam and creating an impoundment by holding back the flow of some waterway. Any silt or nutrient load carried by the waterway can create problems such as are encountered in natural lakes. The same problems in management arise, along with some new ones. Carp are often a problem, but their removal may result in heavy macrophyte growth if the water is rich in nutrients. Then these plants may be removed, only to have algal blooms take their place. Where cattails are abundant enough to make a monotypic stand, efforts are made to get rid of them, but if they die out everyone is concerned about re- establishing them.. It would seem that managers try by constant manipulation to recover what they see in undisturbed areas. Instead, the approach should be to identify the surface watershed and the ground water sources, consider them as a unit with the wetland, and use an ecosystem approach. Fortunately, this is becoming a more popular idea. It is especially important because the most valuable wetlands are a complex of types. The interpretations must be different for each area considered. We are a long way from having the field data we need for computer modeling of wetland ecosystems to solve such problems. Once the imaginary limits to the ecosystem have been drawn, following natural guidelines, sources of problems must be iden- tified and these alleviated. Otherwise, proper management becomes a hopeless task. Within the wetland itself certain questions must be answered. What general cover-water interspersion is desired, how can this be achieved by natural or quasi-natural means, how long are managers willing to wait for results, can waterfowl be attracted other than by frequent water level fluctuations, and so on. Successful deep water marsh management looks possible, given four things: (1) power to relieve watershed problems; (2) carefully studied techniques based on observed natural processes; (3) feedback and re-examination; and (4) patience, For instance, in our experience, cattail management would seem to require several things, There should be enough muskrats to provide openings. Manipulation results in wide fluctuations in cattail density and muskrat populations, with no chance for the system to stabilize. Since cattail is depth-sensitive (~ac~onald,19551, minor unevenness of Me bottom is important. water level should be chosen for an average desirable cover- Tlle water ratio,.and allowed to vary within natural limits. Studies should be made in natural cattail areas to understand what controls exist,

FURTHER RESTORATION NEEDS Sedge meadows may be more difficult to rehabilitate. No work has been done on them because they are not easily identifiable with waterfowl, other game, or fish. They do of course have wildlife value, but their major value is probably in watershed protection. If they are to be reflooded to achieve that, it stands to reason they should be given a chance to regain their esthetic qualities. Ditches can be reconverted into meanders, for instance. As the water level comes up, shrubs should thin out. Historical information can be used to guide restoration goals. Our sedge meadows are mostly on large peat depasits. Deep flooding is likely to cause the peat to float up, perhaps in chunks. This is more likely to create a botanically interesting early-succession cornunity (although we do not really know, since our sedge meadows have mostly been drained rather than flooded) than a deep marsh for waterfowl.

We have no information on bog restoration in southern Wisconsin, Bogs are still an object of human desires to "improve" the natural landscape rather than restore it. Since peat oxidizes much faster than it is created (in years as opposed to centuries), once a bog has been drained and cultivated for a while it may be difficult to restore. The major problem in studying this matter is to obtain suitable bogs to experiment on. One nimprovement" practice that is not recommended is the addition of nutrients or lime to bog water to create waterfowl or fishery areas, because bog vegetation appears to abhor minerals, Level ditching, potholes, and excessive flooding are also not recommended. Similarly, surface runoff must be kept clean and controlled in quantity if bog plants are to be restored. They do not tolerate rapid fluctuations in water level. L Trout streams are being rehabilitated in Dane County. Part of the Upper Sugar River was rehabilitated by Paul Olson's work- learn program, the Dane County Conservation League, and the Department of Natural Resources working together. They fenced the stream, provided cattle crossings, and placed deflectors to re-establish meanders. However, some farmers don't participate because the Department of Natural Resources1 help means granting public access. The plan by the Dane County Conservation League, Department of Natural Resources, and Soil Conservation Service to rehabilitate the rest of the Sugar River system is admirable, and should be extended to,includeBlack Earth Creek, a valuable trout stream which is now endangered in several ways. Fen restoration has also not been pursued. In fact, only a very small percentage of our fens remain. This is unfortunate, since southern Wisconsin may have been one of the most important fen areas on the continent. Most important here is removal of drainage ditches so ground water discharge is allowed to keep the peat wet. In addition, ground water discharge itself must be protected by careful planning of well placement. When this is accomplished, the vegetation can be studied to see if fen will re-establish itself. A seed source may be necessary, or perhaps control of exotics, Where the sanitary sewer was laid through one of Cherokee's best fens at Wheeler Road, restoration by natural processes looks possible; tree seedling removal and study are progressing, THE NEED FOR MONITORING

Monitoring is a key concept about which we hear very little. Some of the factors that need monitoring are water quality, water levels, ground water, vegetation, and wildlife use. There are several reasons to monitor rather than to take one or a few measurements. One is simply to learn what is going on and how things work. Without this information restoration is difficult if not impossible. Another is to find out what the land use effects are at the moment so proper steps can be taken in time to protect the wetland. This is very important, especially for the Priority I wetlands listed in this report. It is also desirable to monitor one's own activities, such as brushing, burning, changing water levels, and so on. Where possible, experimenting should be limited to a small area. The more potential impact a management t'echnique has, the more important it is to monitor the ecosystem before, during, and after applying it. Otherwise, the results may not be fully understood. This seems obvious, yet it seems to be rarely practiced. A start is now being made by the U. S. Geological Survey at Nine Springs and the Arboretum.

WETLANDS AND THE PUBLIC

A number of lesser points need to be made, all important but applicable only after the crucial matters are taken care of. Public education must involve landowners. We found owners of wetlands with all attitudes from exploitative through unin- formed to deeply concerned. Since in our present land use system the owner has great power, education is one alternative to leaving preservation to chance.

In those areas where wetlands receive public use, sensitive portions should be protected from trampling. Bogs, fens, and low prairie are especially delicate in this respect. A number of class trips into such an area can leave a long-lasting mark on the vegetation. Locations of highly sensitive areas are best not advertized. Further, there should be an area where few people disturb the wildlife. An important example is the waterfowl- restins area at Lower Mud Lake. No road shouid be extended to the water's edge. People stopping cars and getting out would make the ducks nervous and drive them to the far side. A barrier on the north or east side of the lake, behind which observers might stand, would be helpful. Motorboats should be strictly prohibited from waters where birds are resting and feeding; even canoes can be disruptive. Areas where public recreation and education are planned should at least have part-time naturalists to guide use patterns. Wilderness is defined as a place where man is only a visitor. However, it is more than that; it is a place where man can renew his ancient bonds with nature, seek his place in the scheme of things, and find inner peace. This need is as real as the need for financial support because we are at once intellectual and emotional beings. This is what is referred to.when people urge that the quality of life must not be sacrificed for the standard of living. It is hard to maintain a balanced outlook on life when we are cut off from contacts with nature, when we are con- fronted only with the predictability of the manmade world and unable to seek the inspiration of the natural one. Since wetlands are not suitable for economic development through alteration and since they can form nuclei for wild areas, man and nature can benefit together from their preservation. Some needs of the public in using wetlands (and other natural areas) : Isolation and sense of being on own resources Quiet Diversity in experiences, scenery, etc. Game animals and fish, furbearers, other animals to hunt, trap, or observe Interesting plants to observe Self-education Sense of being close to nature, personal renewal

This brings up the matter of access. It is often argued that to limit access to those who are able to or prefer to hike or canoe in is discriminatory. The trend is to get everyone into public land with as little effort expended and as many amenities provided as possible. It is too much access which is actually discriminatory, because many people need the sense of isolation and accomplishment which comes with making an effort to get away from human disturbance, and they need to find natural conditions when they finally arrive. It is our belief that more people woald discover this pleasure if they had the chance. We therefore urge a variety of accesses and park developments, geared to suit: (1) the sensitivity and natural value of the land in question; and (2) the diversity in human tastes. For instance, Hook Lake and much of the Goose Lake Public Hunting Ground are areas for which further access improvement or development of facilities are not appropriate. Nine Springs Greenway, being long and narrow, has easy access and could have trails along it. Heavy use would not be incompatible, if the E-Way trails are placed with discretion. A crucial need is the continued identification and protection of natural areas in Wisconsin. Unfortunately, this requires money. It is frustrating for concerned citizens to watch valuable areas go unprotected because of insufficient funds. We hope that in the near future the Scientific Areas Council will be adequately funded to do this necessary job. In the case of wetlands, this means protection not only of the wetland itself but of an adequate buffer zone. One factor in wetland purchase that concerns us greatly is to see the - - Department of Natural Resources purchase only the wet area and a small, inadequate buffer strip. The surrounding upland pieces can then be sold more easily to developers, and without adequate zoning the result is more stress on the wetland. An alternative approach would be to purchase upland parcels as well and resell them with deed restrictions. Another concern is the lack of education of hunters. Almost anyone can hunt in this country, provided they follow the law, In some European countries, one must prove knowledge of gun handling, regulations, and species recognition. It would further help to have education on the value of predators and on the need to protect game populations where threatened. The decline of the canvasback has been brought to our attention, for instance. This is one of the species seen in our deeper, more open wetlands, and in open lakes. Fortunately, nuntingof canvasbacks, and redheads as well, is now restricted (DNR, 1974). However, it has been shown that hunters often misidentify the ducks they bag (Jahn and Hunt, 1964)- Improved water quality and better water plant diversity are also needed, of course. Also, there is no limit to the number of muskrats, turtles, or frogs that may be removed from a wetland. Since muskrats are closely associated with vegetation patterns, some approach should be found to limit local harvests according to population fluctuations and vegetation density. Finally, it should be noted that exploitation of wetlands does not solve any problems, only creates many. It may be useful on a short-term private basis to increase the area of cultivated land, of industrial sites, or of golf courses for new housing developments. However, in the long run, it does not help the public interest. At best, exploitation destroys useful and esthetically valuable resources; at worst, it also puts off the question of having enough land to support the growing population. FUTURE USES OF WETLANDS

Although there are not a large number of directly economic uses of wetlahds which are compatible with their continued healthy existence, several other important uses must be considered. They are: watershed protection, research, education, species reserves, and recreation and esthetics.

NEED FOR RESEARCH

As must be apparent to the reader at this point, the understanding of wetland processes and types is woefully inadequate for the protection and management task facing us. This is especially serious because wetlands, in as nearly undisturbed a state as possible, are needed for study as baselines against which to measure the effects of human alterations..- In searching the literature for this report, we found information especially lacking in certain areas. For instance, hydrology has been studied at length for applications in well drilling, municipal water use, and stream flow, but almost not at all from the point of view of natural springs and wetland maintenance. Only one brief descriptive work (in German) on springs was found. Wet- land soils have been studied both in this country and in the Soviet Union with regard to agricultural use, but little can be found on peat formation in non-boreal regions. The effects of wetlands on water quality are beginning to be studied at the Water Chemistry .Department of the University of Wisconsin. In the past, the emphasis of studies has been more on description than on process, since knowledge of the former paves the way for study of the latter. Some needed research efforts discovered during our field work, literature study, and formulation of management suggestions for the Dane County wetlands inventory are listed here, using general categories. In many cases, some work on the subject has been done, but results are incomplete or not applicable in this locality. Undoubtedly some of these studies are being undertaken elsewhere at present. Much of this material simply points out the need for testing general hypotheses in wetlands, but much refers to projects which apply to wetland processes or management only. Most of these projects could be undertaken in Dane County or elsewhere in southern Wisconsin. The starred items apply especially to the county. a) Hydrological and biological processes * Identification of ground water recharge areas affecting given wetlands, comparison of recharge and discharge rates under various conditions. * Identification of wetlands dependent on ground water for survival, which,in Dane County, may include most of them. Rates of peat deposition related to various types of springs and seepages. * Measurement of nutrient content of overland versus ground water flow into wetlands. Effects of various types of artificial drainage on ground water, water chemistry, vegetation (some work has been done) . Further detailed studies of processes in various types of wetlands involving nitrogen and phosphorus storage and release. Nitrogen and phosphorus process rates in wetlands related to watershed conditions. Rate at which bottom diversity develops, roles of deposition, vegetation, muskrats, etc. Maximum height of peat development compared to average water table, related to physical factors. Monotype formation, as in cattail stands. Effects on vegetation of constant water level versus rapid changes. Further study of nutrient use and feedback mechanisms in algal blooms.

Effects of silt on benthic organisms (see Ellis, 1936). Effects of wetland groupings on wildlife use. Wildlife use patterns in various types of vegetation and edge. Effects on peat formation, water chemistry and temperature, plant communities, wildlife, and fish of digging out of springs and seeps. Vegetation cycles in southern Wisconsin sedge meadows, fens, and bogs due to water level changes and fire, further detailed study. * Monitoring of processes in local areas to document natural and man-made effects. b) Species and communities Testing of "hydrosere" or lake-to-dry land succession concept, climax concept in wetlands. Pioneer plants and first peat buildup. Species diversity, controlling factors including structural diversity, in various types of wetlands. Interactions among wetlands in a geographical group, such as use by waterfowl traveling from one to another. Effects of species removal and addition on ecosystem. Effects of wetland dominants. Environmental gradients and plant species distribution. Viability of relic bogs. c) Understanding of various wetland types Similarities and differences between southern Wis- consin wetlands and those in other regions. Comparative wildlife and fish use of various wetland types. Effects of sedge meadow, fen, bog, and low prairie plants on microclimate, soil formation and chemical composition, water chemistry. Effects of soil and water chemistries on sedge meadow, bog, fen, and low prairie plants. Species diversity in various wetland types, relationships. d) Prehistoric changes History of peat deposit from dating of specimens from various levels. Rate of past peat deposit, and mode of filling of the basin. Record of plant and animal species in peat deposit. e) Rehabilitation techniques * Feasibility of re-establishing sedge meadows with limited flooding. * Feasibility of re-establishing meanders in wetland streams, effects on water table, water quality, fish habitat, vegetation, and flood peak abatement. * Relative evaluation of undisturbed and restored wetlands of various types. * Artificial versus natural shrub control. * Experiments in restoration of water quality. * Control of various exotics in wetlands. * Restoration of native vegetation. f) Identification of wetlands in surrounding areas especially needing study and preservation

EDUCATION Education is an extremely valuable use of wetlands. It generally falls into three categories: primary and secondary, advanced, and public. At the primary school level, children are extremely impressionable. It is at this age that formation of attitudes toward the environment is occurring. Children naturally react with fascination toward plants and animals, un- hampered by preconceived notions. By taking classes to Dunn's Marsh we found that observing frogs and insect larvae in the hand and collecting plankton and other material for aquaria could excite and involve children (P1.47). Water environments offer much more personal contact with animals and motile organisms such as plankton than do terrestrial ones. This approach can continue into secondary school biology classes while providing basic concepts. Advanced education implies college and graduate level. This includes both class field trips and research projects. Even though wetland destruction is so general, there still remain more wetlands than uplands in the Dane County area which are in a condition suitable for teaching and studying natural processes. Thus, the disappearance of wetlands would rob the educational system of a valuable asset. Public education is aimed at broadening adult viewpoints with the objectives of bringing a richer life to people and protecting natural resources as well. It would be circular reasoning to suggest wetlands be preserved to educate people so they will continue to preserve wetlands. However, important concepts such as that of proper land use can be brought home to people by observing wetlands. They can see the results of siltation and deteriorating water quality. The drying up of wetlands is a visible demonstration of the lowering of the water table. With the public solidly behind wetland preservation, these systems can continue to function to the Senefit of the entire environment, In attempting to protect the wetlands, people will find they must also protect a number of other important environmental values.

SPECIES PROTECTION Wetlands are important as plant and animal species reserves. The complexity of interactions where land and water meet has been discussed. Some specific points need elaboration. Waterfowl breeding and resting areas must be spread out over a large area, Since waterfowl on migration can only stop at habitats suitable for their resting, feeding, and protection from predators, a network of such places is needed across the country. It is important not to concentrate large percentages of the population in a few refuges, where disease or heavy hunting pressure can be harmful. The number of breeding localities probably controls the overall population, Since waterfowl populations are down throughout the continent and hunting pressure is still high, every appropriate breeding site needs protection. Some wetlands are important spawning areas for northern pike. They swim the length of Simile Creek to spawn at Waunakee Marsh, for instance. South Waubesa Marsh is important for northern spawning also, as well as for maintaining a quality fishing area in the lake offshore. Weedbeds are used by other fish species also, such as nesting bluegills. Fish are dependent on microhabitats for cover and food. Bottom diversity and vegetation diversity in streams, lakes, and wetlands are important for this. Since wetlands protect water quality, fish benefit in a more general way. For instance, if a marsh soaks up nutrients, algal blooms are less common and fish die-offs may be prevented,

Wetland non-game species also need the protection afforded by proper habitat, Wetlands must be abundant and diverse enough, and properly distributed so they can move from one to another. For example, if the water in one marsh is too deep in a certain wet year, yellow-headed blackbirds move to another which has become deep enough. If not enough alternative habitats were available for some to be unoccupied, the blackbirds could not breed. An argument has been made that if one wetland is destroyed, the birds, for instance, can just move to another. However, these species are generally territorial and the territories tend to be already filled; the more likely result is that the displaced individuals cease to breed. Predators form an important, but poorly understood and little- protected segment of the ecosystem. The larger ones are often persecuted. The existence of wetlands provides alternate food sources for them as well as refuges to escape from human pressure. In addition, there are predators of many types within the wetland ecosystem, some of which are important to man in keeping the system balanced. Predatory fish, such as northern pike and gar, are examples. Genetic diversity is a subject which does not get enough attention. Not all members of a species are alike. The existence of genetic diversity is necessary for natural selection to occur and keeps the species adapted to the local range of conditions. By reducing this diversity, such as by destroying wetland habitats or by removing all fish from a number of streams, a trend toward a more uniform population is set up. The more uniform the population, the more difficult it is for it to adapt to environmental change. In past geological ages, populations were often reduced, but not in an across-the-board manner such as results from human interference. Only poorly adapted species or individuals might have been affected, or populations in certain areas might not have survived. Wetland destruction is a nationwide problem, affecting all wetland plant and animal species. What has just been pointed out is a need for species protection for the sake of their survival as parts of the living system. From the human point of view also, protection of rare species is needed. Only a human being can appreciate that which is rare. Scarcity can be the result of any of several factors, as noted above: natural rareness in the community of which it is a part, perhaps due to competition, low population due to evolutionary changes, or population loss due to habitat or organism destruction by man. If the species is naturally rare in its community, a large number of communities must be preserved to protect it. As for evolutionary trends, these have almost never been considered before the undertaking of any sort of habitat destruction. Since wetlands have fared better than uplands in southern Wisconsin, it is not too late to protect species. At present, we probably cannot even state whether a given species is naturally dying out or may in the future become important. Preservation affords time to find out. Habitat destruction as a cause of rareness of species is relatively easy to identify and can still be controlled and even reversed. LEGAL AND LEGISLATIVE AIDS TO WETLAND PROTECTION

As of early 1974, legal recourse available for wetland preservation is limited. No legislation yet exists in Wisconsin whose primary goal is the protection of wetlands, per set with emphasis on quality. In fact, laws still exist which allow for the formation of agricultural drainage districts aimed at im- proving present drainage and making additional land suitable for cultivation. Since no strong direct protection exists for wetlands, and since the public did not until recently recognize their value, many important wetlands have been lost. Those which remain owe their continued good condition to chance. A partial list of such wetlands in Dane County includes: +* Cherokee Marsh (largest known southern Wisconsin ten, low prairie, public education) Dunn's Marsh (deep marsh, public education, recreation) + Fish Lake (large least bittern population, unique sedge mat, rare fish and plants, research value, recreation) + Hook Lake (rare, soft-water southern bog, research value, education, recreation)

Lower Mud Lake (waterfowl) + South Waubesa Wetlands (springs, fen, wildlife, research value) (* = presently endangered; + = recommended at least in part as a Scientific Area.)

None of the above could be restored to their present value with knowledge we have now or are likely to have in the foreseeable future. Wetland protection in Wisconsin depends on several indirect approaches. Some of these are: Shoreland and floodplain zoning, Wisconsin Water Resources Act of 1965, which does not cover all wetlands; Protection of navigable waterways, recently strengthened by the Just Decision (see below); Pollution control efforts, now increasing in effectiveness; Department of Natural Resources purchase under ORAP-200 or the Scattered Wetlands purchase program for hunting and fishing, limited by funds and by local concern over the tax base; Incorporation into the Scientific Areas system, a process barely begun with wetlands, limited by low funding; Purchase by various local public agencies, limited by funds, political pressures, and jurisdiction; Purchase by the Nature Conservancy or protection by concerned landowners, limited by funds, public education, and personal whim.

Positive actions needed include: A common direction on a statewide basis for land use and environmental and resource planning, a concept which many still oppose; Agricultural and conservation tax relief, particularly in developing areas, now made possible by a recent referendum; Citizen input on environmental impact concerning all valuable natural areas, not just those in public ownership; Erosion control governing developing areas; and encouragement of Soil Conservation Service upland projects organized by watersheds; Backing by the U. S. Department of Agriculture for wetland preservation, now weak and sporadic.

For a more complete discussion of wetland preservation, in the light of what has been done and what needs to be done, the reader is referred to the thorough treatment in Managing Wisconsin's Natural Resources (Natural Resources CouncilofState Agencies,1973). Two further points should be made here. First, the much- needed legislation to set up a permit system governing wetland alteration, allowing compensation where no permit is granted, was not passed in 1974. This marks the second such failure. Opposition by the agricultural community is probably the greatest obstacle, yet with proper land management and tax structure such a conflict need not arise. Second, substantial progress was made by the decision handed down by Chief Justice Hallows in the case of Just v. Marinette County.* We quote some of the most important statements here:

* Just v. Marinette County (1972),-56 Wis.2d 7, 201 N.W. 2d 761. "To state the issue in more meaningful terms, it is a conflict between the public interest in stopping the despoilation of natural resources, which our citizens until recently have taken as inevitable and for granted, and an owner's asserted right to use his property as he wishes." "In the instant case we have a restriction on the use of a citizen's property, not to secure a benefit for the public, but to prevent a harm from the change in the natural character of the citizen's property. We start with the premise that lakes z-nd rivers in their natural state are unpolluted and the pollution which now exists is mamade. The State of Wisconsin under the trust doctrine has a duty to eradicate the present pollution and to prevent further pollution in its navigable waters. This is not, in a legal sense, a gain or a securing of a benefit by the maintaining of the natural status uo of the environment. What makes this case di& erent rom most condemnation or police power zoning cases is the inter-relationship of the wetlands, the swamps and the natural environment of shorelands to the purity of the water and to such natural resources as navigation, fishing, and scenic beauty. Swamps and wetlands were once considered wasteland, undesirable, and not picturesque. But as the people became more sophisticated, an appreciation was acquired that swamps and wetlands serve a vital role in nature, are part of the balance of nature and are essential to the purity of water in our lakes and streams .I' "An owner of land has no absolute and unlimited right to change the essential natural character of his land so as to use it for a purpose for which it was unsuited in its natural state and which injures the rights of others. The exercise of police power in zoning must be reasonable and we think it is not an unreasonable exercise of that power to prevent harm to public rights by limiting the use of private property to its natural uses. "

"It seems to us that filling a swamp not otherwise commercially usable is not in and of itself an existing use, which is prevented, but rather is the preparation for some future use which is not indigenous to a swamp."