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Home , Prairie, Tallgrass prairie

The Tallgrass

Prairies once accounted for twenty-four percent of the total land cover worldwide (Howell & Kline 1987). In , extend from the western boundary of the eastern to the base of the from southern and to central . The grasslands shift in composition and height with , mixedgrass prairie and distributed from east to west, respectively. The tallgrass prairie receives more rainfall, and has greater species richness and more dominant species than the shortgrass or mixedgrass prairie (Cochrane & Iltis 2000).

Although grasses comprise only 10% of the species, they constitute most of the in tallgrass . The dominant grasses vary across a moisture gradient ranging from xeric (dry), mesic (moist), and wet prairies. Common grasses include little blue stem (), big bluestem (Andropogon gerardii) and indian grass (). , another important prairie component, align themselves along a similar moisture gradient. These herbaceous species add seasonal color and texture to prairie . Besides grasses, the most common plant families in tallgrass prairies include composites and legumes (Cochrane & Iltis 2000).

Climate change during the Holocene played a role in determining the distribution of prairie in the Great . High temperatures and periodic summer favor over forest. Fire and also influence the distribution of prairie, especially along the margins of its range. The rolling topography of the covered with flammable plant material encourages the spread of fire through the . The lightning fires and frequent burns by the Native Americans slows the invasion of woody species, hinders competitive grasses, and reduces litter in the prairie. Grazing by ungulates alters the landscape by removing plant material, concentrating nutrients, trampling, and influencing decomposition (Cochrane & Iltis 2000).

Currently, the tallgrass prairie ecosystem is one of the most threatened in the Midwest ( Department of Natural Resources 1995). The relatively flat topography and fertile prairie encouraged the conversion of prairie for agricultural purposes. Of the remnant prairies that remain, most are dry prairies found on steep slopes, or mesic prairies located along railroads and in cemeteries. Due to an invasion by woody species, overgrazing, and poor management practices, many of these remnant prairies are severely degraded and have lost many plant species (Leach & Givnish 1996).

Regional context The tallgrass prairie ecosystem occupies a large portion of the Upper Midwest region of the United States, including , Wisconsin, Michigan, , , and . This geographic region has ample fresh water and fertile land. With the exception of Iowa, each of these states border at least one of the : Michigan, Superior, Huron, or Erie. Most of the Upper Midwest was once covered by the Laurentide Ice Sheet with the exception of the in southwestern Wisconsin and the southernmost reaches of Indiana and Illinois (Cochrane & Iltis 2000). The glaciers shaped the land in many ways, leaving behind , outwash plains, and kettle holes. The resulting topography consists of gently rolling hills and large flat expanses punctuated by lakes.

The region epitomizes the humid continental climate type characterized by warm summers and long, cold winters. The Great Lakes buffer the surrounding areas providing cooler summers and milder winters. The amount of rainfall ranges from 63 to 100 cm of precipitation annually (Mattson 1996)

Figure 1. Mean monthly temperature (above) and precipitation (below) for Madison, Wisconsin, USA, for the years 1971-2000 (Lindstrom & Young 2002)

Prior to European settlement, many factors including climate created a gradation of boreal forest and mixed hardwood in the north and tallgrass prairie and in the south. Most of the fertile land that was once prairie and has been converted into farmland and . Corn, soybeans, dairy products and are the most common agricultural uses, bringing in at least 3 billion dollars annually in each state (Mattson 1996). Significant areas were retained as woodlots, but these have grown up to form dense stands of shade-tolerant characterized by a reduced number of the species that were abundant.

The richness of the prairie soils attracted immigrants from Northern Europe. By 1880, over two-thirds of all immigrant farmers had settled in the Midwest (Hurt 2001). The immigrants who settled in the region were motivated to improve their standard of living and brought “strong beliefs and moral values that encouraged hard work” (Hurt 2001). After many years of cultural give-and-take, the distinctive Midwestern culture emerged, characterized by a strong work ethic and moderate conservatism.

Local context The Curtis Prairie is located in Madison, Wisconsin. As both the capitol of Wisconsin and home of the state’s largest university, Madison has a population of 298,054 (U.S. Census 2002). Curtis Prairie (W89.4°, N43.1°) is a restored tallgrass prairie that is situated within the University of Wisconsin-Madison . It represents one of thirty-one biotic communities included in the University’s 500-ha Arboretum. Aldo Leopold, a forward- thinking professor at the University, recognized early on that native communities were being lost and suggested in 1934 that the Arboretum (then a farm) could ultimately provide a “sample of what Dane county looked like when our ancestors arrived here” (Blewett & Cottam 1984; Sachse 1965). Based on U.S. Government Land Survey records from 1835, the presettlement condition of the Arboretum consisted of oak openings and marsh. The uplands contained bur and white with about 36 to 48 trees per hectare. Prairie grasses, prairie forbs and shrubby black oaks made up the ground cover (Blewett & Cottam 1984; Curtis 1951).

The 25-hectare area that would become Curtis Prairie was first settled for farming in 1836. After eleven owners, the Bartlett family purchased the land in 1860. By 1863 the western two-thirds of the land was regularly plowed and planted with corn, oats and pasture in rotation. The wetter eastern third was probably not plowed, with the northern section undisturbed and the southern half used for a mowing . The Bartlett family abandoned cultivation in 1920. The land was fallow until 1926 or 1927 when a veterinarian named West leased the land to pasture 35 to 40 horses. This pasture incorporated the eastern third of the property including the previously undisturbed section and the mowing meadow (Blewett & Cottam 1984).

By 1932 the Arboretum was becoming a reality. In that year a part of the Nelson farm was purchased, and in 1933, the University of Wisconsin regents purchased the Bartlett farm. When the fields were purchased, quackgrass (Agropyron repens) dominated the fields. Eventually, two bluegrass species (Poa pratensis and P. compressa) took over (Blewett & Cottam 1984). All three species are considered weedy and non-native components of tallgrass prairies. The creation of a prairie within the Arboretum proved challenging. Not only was this the first ecological restoration, but also there was little tallgrass prairie habitat left to characterize reference conditions due to conversion to . In The Vegetation of Wisconsin, John Curtis (1959) estimates the original area of over 800,000 hectares has been reduced to remnants, with none larger than 16 hectares.

Restoration approaches The restoration goal was to replace pasture and ruderal vegetation with species of native plants for use in research and education. Over the decades that followed the dedication of the Arboretum in 1934, scientists from the University of Wisconsin conducted many experiments involving planting methods and controlled burning. These experiments were aimed at increasing the number of native plant species and decreasing the abundance of weedy and exotic plant species.

From 1936 to 1940, Dr. Theodore Sperry directed the first effort to establish a prairie with supervision from Aldo Leopold and William Longenecker. About 200 recruits of the Civilian Conservation Corps (CCC) planted 42 plant species in large blocks within 237 plantings. Three methods of planting were tested: seeds, seedlings and sod transplants. This approach likely represents the first example of experimentation in a restoration site. Prairie remnants along the Wisconsin River provided a source of native seeds and sods, and the seedlings were cultivated in a nursery within the prairie. The establishment rates for the planting treatments were similar, but the sod transplants had slightly higher survival; however, the expense of the sod techniques far outweighed the benefits (Blewett & Cottam 1984). Between 1950 and 1957, a second major planting program added 156 species to selected areas of Curtis Prairie. New planting methods were utilized: seed casting after a burn, hand insertion of large seeds, transplanting sods, and disking followed by seed casting with the addition of cover crops. The last method provided the best results (Blewett & Cottam 1984; Wilson 1964).

Curtis Prairie also supported experiments on preparation, plant competition, controlled fire treatments, and germination studies. John T. Curtis, Professor of Botany at the University of Wisconsin, carried out many of these important studies. Between 1937 and 1948, 91 species were collected from prairie remnants in southern and western Wisconsin for germination experiments. Most prairie grass and seeds were shown to depend on stratification (overwintering or cold treatment) for germination (Green & Curtis 1950).

Between 1941 and 1946, John Curtis and Max Partch studied the effects of fire on the competition between bluegrass (Poa spp., from the former pasture) and prairie plants. They applied controlled fire treatments to plots burned in March, May or October on an annual or biennial schedule. Bare ground, prairie perennials and weedy forbs greatly increased in the burned 7.6m x 67m plots, but after six years, the bluegrass was reduced to one-fifth its original area in the burned plots (Blewett & Cottam 1984).

When Curtis became the Arboretum Research Coordinator, he scheduled prairie burns with a frequency of about every three years and every other year in some areas (Blewett & Cottam 1984). This burn frequency was increased by Virginia Kline (1986), in light of her research on the response of the biennial sweet clover (Melilotus alba) to consecutive burns. Because the growth and reproduction of sweet clover occurs within two years, portions of the prairie with burns over two consecutive years greatly reduced the population of sweet clover. Thus, experimentation has characterized attempts to increase the ratio of native prairie plants to invasive species throughout Curtis Prairie’s history as a restoration site.

Environmental Changes Affecting Curtis Prairie As the city of Madison grew up around the Arboretum, highway 12-18 (also known as the “beltline”) to the south of Curtis Prairie was widened in 1956, causing a substantial loss of the buffer of planted pine trees (see ORTHO PHOTOS from 1949, 1962, and 2000). Also, the roadwork caused as well as deposition of sediments that buried some of the prairie (Blewett & Cottam 1984). Additional roadwork in 1959 and increasing runoff from urban development to the south perpetuated the problems of urban runoff. By 1969, a siltation pond had been added near the southern edge of the prairie to collect flows from a culvert that conveys urban runoff under highway 12-18. Because Curtis prairie slopes gently from southwest to northeast, water flowing out of the pond gradually eroded a creek that now dissects Curtis Prairie, providing opportunity for the extremely aggressive reed canary grass (Phalaris arundinacea) to establish along the creek’s floodplain.

Constructed pond at southern edge of Curtis Prairie Reed canary grass (Phalaris arundinacea) (photo courtesy (photo courtesy of M.Arndt) of M. Arndt) Reed canary grass from above: outlined areas indicate high coverage of reed canary grass, (Phalaris arundinacea) (photo courtesy of J. Zedler)

A north-south road historically used as a fire lane impounded runoff and allowed a stand of willows (Salix exigua) to establish along with reed canary grass in the wettest areas. Recently, an “Arizona crossing” was installed to allow flow over the road, but the willows remain and have not significantly decreased despite management burning.

Finally, the pine trees that were planted as a buffer along the highway have grown tall, shading the prairie’s southern edge while functioning less as a noise and visual block to an increasingly busy traffic route. The degradation of the southern edge of the prairie was increased by the disposal of dredge spoils from the detention pond, which were placed in a linear mound that is now dominated by reed canary grass.

Concerns about the Status and Sustainability of Curtis Prairie As the first ecological restoration project, work at Curtis Prairie began when little was known about the ecology of prairies in Wisconsin. The site has always been valuable for research, and plant composition continues to be assessed at about five-year intervals. The question remains as to how much Curtis Prairie resembles a native tallgrass prairie. An early comparison of Curtis Prairie and native prairie remnants showed that the vegetation and community structure were similar with the exception of far more non-prairie species in Curtis Prairie (Cottam & Wilson 1966). Also, a University of Wisconsin Soil Scientist, Francis Hole, found that the site was beginning to recover prairie soil characteristics. Whereas 90 years of agricultural use likely oxidized 50,000 kg of organic carbon per hectare, about 60% was regained between 1940 and 1959. While the soils of Curtis prairie are beginning to recover their former structure, prairie soil horizons form over long periods of time, developing in 500 to 4,000 years (Anderson 1972).

Plant community structure and soil formation are indicators of restoration progress but not necessarily of the site’s ability to support native wildlife. Native in Curtis prairie includes deer and coyote. and , along with larger carnivores, are absent and clearly never will be present because the site is too small to support them. Small mammals and arthropods are limited to generalist species. The status of the fungal and bacterial communities of the soil is largely unknown. Mound building ants are the major soil cultivators of tall grass prairie, but ant mounds are only present in the unplowed area in the eastern section of Curtis Prairie (Howell & Kline 1987). Likewise, many of the grassland bird species that are declining in grasslands region wide are missing including bobolinks and Henslow’s sparrows (Mossman 1984).

At present, most of the management decisions being made for Curtis Prairie concern fire regimes and use of herbicide to control invasive species. The current fire management regime burns each part of the prairie two out of three years on average. This pattern of burns controls the outbreaks of sweet clover with only an occasional need to weed this species by hand. Frequent burns not only control invasive species but also curtail the encroachment of woody species into the prairie.

The problems associated with the urban development around Curtis Prairie, such as reed canary grass, continue to challenge restoration ecologists. These types of management issues at Curtis Prairie illustrate the need for adaptive management. Currently, the management decision-making process includes the Arboretum Ecologist who devises the management plan and the Land Care Manager who supervises the implementation of the plan. The Arboretum Ecologist and the Land Care Manager receive feedback from researchers on a monthly basis via a "Research Coordination Group". The Arboretum Ecologist and Land Care Manager report to the Arboretum Director who is supervised by the Dean of the Graduate School. While this system allows for both structure and flexibility, it does not fulfill the need for adaptive management.

Throughout its 68-year history, experimentation and management of Curtis Prairie has significantly increased our understanding of . Current prairie planting techniques and burn schedules have benefited greatly from the early experiments conducted on Curtis Prairie. This restoration also highlights the influence of the surrounding landscape on processes at the restoration site. The altered hydrology due to urbanization within the watershed requires continuous monitoring and management of the prairie. While Curtis prairie may be the oldest in the world, it is clearly still a work in progress.

Study questions and problems

1. Can ecological restoration be expected to be complete where the land is surrounded by urban land uses? Does an urban context offer any potential benefits to restoration projects?

2. What strategies could be used to inform and engage the local community and political processes in decisions related to prairie management and preservation? What role/s could or should the public play in preserving or managing the prairie? How would you involve the local community and manage their involvement?

3. How would the prairie benefit with the creation of landscape links, and what kinds of wildlife corridors might facilitate use by animal populations?

4. Are disturbance regimes in Curtis Prairie likely to mimic those of natural prairies? Consider the lack of large digging mammals, such as badgers, as well as fire and influxes of aggressive plant species.

5. How would we determine the relationship of food webs in Curtis Prairie with those of natural prairies?

6. What factors might prevent ants from colonizing the restored prairie?

7. What should we know about soil microbial communities to improve our understanding of restoration effectiveness?

Projects

Devise a mechanism to achieve adaptive management at Curtis Prairie. Include a description of how the system operates along with a diagram to illustrate the structure of the decision-making process.

Models are important tools to identify restoration issues and to develop a management plan. To devise a conceptual model of Curtis Prairie, use the following components:

 Drivers/sources (square): the external forces that influence natural systems at large scales  Stressors (rectangle): the physical and biological changes caused by the driver  Ecological effects (diamond): the biological responses caused by the stressors  Attributes (hexagon): indicators or endpoints that represent the overall ecological condition of the system  Measures (parallelograms): the feature of each attribute to be monitored

In addition to the conceptual model, include a narrative with an introduction to the landscape and descriptions of the stressors, drivers, and attributes. Explain how these components relate to the ecological effects and how the measures will contribute to the management of the landscape. For more information and examples, refer to the Ecological Conceptual Models in the Comprehensive Restoration Project,http://www.evergladesplan.org/pm/recover/recover_cerp_monitor_plan_1.cfm

Potential Term Paper Topics

 Might climate change be a major concern for the future sustainability of Curtis Prairie? Are there ways to plan for changes in climate through species introductions or changes in management?

 What components of urban runoff (water, nutrients, sediments, toxic materials) deserve the most attention in managing for ? Provide evidence for your argument from the scientific literature and/or suggest experiments to determine which components are most important. Are there innovative methods for restoring the prairie’s natural hydrological conditions (i.e., ways to reduce or eliminate inflows of urban runoff)?

 Of the factors influencing restorability, how would you rank hydrology, soils, microbes, vegetation, and animals, in their importance? Would this ranking change in that are less disturbed than that surrounding Curtis Prairie?

 What management questions should form the basis of future restoration research on Curtis Prairie, and how would you go about such research? Consider these constraints on scientific activities before you respond: The need to control burns strictly, so that adjacent properties are not threatened; need to minimize smoke effects on nearby homes; need to retain access via trails for joggers, students, and public visitors; potential for vandalism; substantial concern about the esthetics of Curtis Prairie.

 What would be the most appropriate reference system(s) for a mesic prairie like Curtis Prairie, now that nearly all of the prairie landscape in the midwestern U.S. has been converted to agricultural and urban land uses? What attributes would one sample in both the reference sites and Curtis Prairie, and why, in order to determine when restoration objectives have been fulfilled? You may wish to consult Egan and Howell’s (2001) book, The Historical Ecology Handbook: a Restorationist’s Guide to Reference Ecosystems, Island Press, , D.C., USA.

References

Anderson, R. (1972) The Use of Fire as a Management Tool on Curtis Prairie. The University of Wisconsin Arboretum, Madison, WI.

Blewett, T.J. & Cottam, G. (1984) History of the University of Wisconsin Arboretum Prairies. Transactions of the Wisconsin Academy of Science, Arts and Letters, 72, 130-144.

Cochrane, T.S. & Iltis, H.H. (2000) Atlas of the Wisconsin Prairie and Savanna . pp. 8-47. Department of Natural Resources, Madison, WI.

Cottam, G. and Wilson, H.C. (1966) Community Dynamics on an Artificial Prairie. Ecology, 47, 88-96.

Curtis, J.T. (1951) Arboretum master development plan: I—The Prairie. University of Wisconsin-Madison, Arboretum.

Curtis, J.T. (1959) The Vegetation of Wisconsin: An Ordination of Plant Communities. pp. 295-307. University of Wisconsin Press, Madison, WI.

Green, H.C. and Curtis, J.T. (1950) Germination Studies of Wisconsin Prairie Plants. The American Midland Naturalist, 43, 186-194.

Howell, E.A. & Kline, V. (1987) Prairie. Restoration Ecology (eds W.R. Jordan III, M.E. Gilpin & J.D Aber), pp75-83. University of Cambridge Press, Cambridge.

Hurt, R.D. (2001) Midwestern Distinctiveness. The American Midwest. (eds A.R.L. Cayton & S.E. Gray) pp. 160-179. Indiana University Press, Bloomington, IN.

Kline, V.M. (1986) Response of Sweet Clover (Melilotus alba) and Associated Prairie Vegetation to Seven Experimental Burning and Mowing Treatments. Proceedings of the ninth North American Prairie Conference. (eds G.K. Clambey & R.H. Pemble) pp.149-152. State University, Fargo, ND.

Leach, M.K. & Givnish, T.J. (1996) Ecological determinants of species loss in remnant prairies. Science, 273, 1555-1558.

Lindstrom, S. & Young, J. (2002) Madison Climate Trends Reflected in Changed “Normal” Statistics. Retrieved September 15th, 2002, from http://www.aos.wisc.edu.

Mattson, M.T. (1996) Atlas of the States. Simon and Schuster Macmillan, .

Mossman, M.J. (1984) Wisconsin Scientific and Natural Areas Breeding Bird Survey, 1984. Wisconsin Endangered Resources Report. Bureau of Endangered Resources, Madison, WI.

Sachse, N.D. (1965) A thousand ages. University of Wisconsin Arboretum, Madison,WI.

Sperry, T.M. (1983) Analysis of the University of Wisconsin- Madison Prairie Restoration Project. Proceedings of the eighth North American Prairie Conference. (ed R. Brewer), pp. 140-146. Western Michigan University, Kalamazoo, MI.

United States Census Bureau. (2002) Census 2000. Retrieved September 2nd, 2002, from http://www.census.gov/census2000/states/wi.html.

Wilson, H.C. (1964) Vegetational history of the Curtis Prairie, 1934-1961. University of Wisconsin M.S. Thesis.

Wisconsin Department of Natural Resources (1995) Wisconsin’s Biodiversity as a Management Issue. A Report to the Department of Natural Resources Managers. Pub-RS-915 9S, Madison, WI.