Research and Contributions to Restoration
As one of the research centers of the University of Wisconsin–Madison, the Arboretum has a long legacy of research and scholarship. The Arboretum’s work has resulted in, among other things, the development of prairie planting and management techniques—including research confirming that prescribed fire is the primary management procedure for tall grass prairies—that are in use today throughout the Midwest. The work has generated hundreds of research papers, resulting in the development of many restoration innovations and research methods.
Generations of faculty, staff, students, and volunteers have contributed to restoration studies at the Arboretum and elsewhere throughout the Mid Western United States. We will look at the stories of these modern day prairie and restoration pioneers in other posts throughout the year.
Here, we report on a long-term assessment of the restoration outcomes of the Arboretum’s signature restoration, Curtis Prairie (pictured above.)
Looking to the Future: Curtis Prairie
The generic restoration goals and objectives for the prairies (“Go plant a prairie” was Leopold’s instruction to Ted Sperry) have had their advantages and disadvantages. The current goal for Curtis Prairie is to “To develop a good example of tall grass prairie, with appropriate species throughout the moisture continuum” (Kline, 1992). The vagueness and general nature of the restoration outcomes has perhaps encouraged generations of stakeholders, researchers, managers, faculty, staff, students, volunteers, and the general public, to stamp the project with their own views of what is desirable and possible . This freedom to interpret the prairie/Arboretum has been, on the one hand, beneficial because it has encouraged, in the social realm a good deal of public interest and involvement–-a citizenry of diverse voices and opinions. On the other hand, it has created the challenging task of reconciling the competing viewpoints of what is socially desirable with the reality of what is ecologically attainable.
Lack of precision in goals and objectives has meant that it is difficult to know all the attributes to measure and monitor, let alone when the desired outcomes are reached. Nonetheless, an assessment of long-term restoration success in Curtis Prairie has recently been compiled (Wegener et al. 2008). The assessment asked and answered four basic questions:
Is Curtis Prairie Uniformly Rich in Species?
The 2002 vegetation survey revealed that Curtis Prairie had 265 species, 230 of which are native (Snyder 2004). Diversity varied across the prairie, with the highest diversity in the never plowed remnant and lower diversity in wetland areas dominated by the invasive Phalaris ardundinacea (reed canary grass) or woody native pest species such as Cornus racemosa (grey dogwood) and Salix interior (willow).
Is Curtis Prairie Restored?
Any restoration is a process rather than a single event; for any given restoration,it’s possible the task will never be completed, and Curtis Prairie is no exception. For example, the site is too small to provide habitat for some species of native grassland birds that would be expected in a mid western prairie restoration. Likewise, there are some native mammal species missing, although one success is that a breeding pair of Grus canadensis (sandhill crane) has nested in the prairie for the past several years.
Does Curtis Prairie Match Natural Prairies in Species Richness?
This is a more difficult issue to evaluate. The main reason is that there are so few remaining native prairie remnants with similar soil and other site conditions, comparable management histories, and existing data sets. Yet, when looking at the entire prairie ecosystem, and remnants within Wisconsin, Curtis Prairie is unlikely to have the representation of species that some of the better remnants contain (some of which are at 400 or more recorded species).
What Are the Persistent Restoration Issues?
Native and introduced woody and herbaceous pest species continue to be widespread, despite 75 years of active management (McGaw 2002; Snyder 2004). The density and frequency of these pests reduce native species diversity, suppress flammable fuel loads, and make the conducting of prescribed fires difficult. In some cases, the early lack of understanding of the use of fire and cutting resulted in stimulating species into spreading via root systems. The management of aspen (Populus tremeloides), for example, was attempted early in the Arboretum history but resulted in its greater spread, and has yet to be brought under full control.
Cross-boundary issues and influences
Storm water runoff has a tremendous impact on the prairie. The estimated annual volume of storm water that enters Curtis Prairie is 64,141 cubic meters or 52 acre-feet (the prairie itself is just over 60 acres). The storm water carries with it sediment, pollutants, and seeds of pest species. It has been shown to facilitate the spread of reed canary grass and has eroded a ditch through the center of the prairie.
Smoke management issues and public safety precautions to protect dense commercial and residential developments in the urban setting require that prescribed fires be conducted under relatively safe and cool conditions. These conditions might mean the fires are not as effective at controlling pest species as naturally set fires might have been historically. Despite these issues, the UW Arboretum has been an active and engaging player in the promotion, practice, and study of restoration for over 80 years.
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Blewett, T. and G. Cottam. 1984. “History of the University of Wisconsin Arboretum Prairies.” Transactions of the Wisconsin Academy of Sciences, Arts, and Letters 72:130-144.
Cottam, G. 1987 “Community Dynamics on an Artificial Prairie.” In Restoration Ecology: A Synthetic Approach to Ecological Research, edited by W. R. Jordan, 257-270. New York: Cambridge University Press.
Cottam, J.T. and H.C. Wilson. 1966. Community dynamics on an artificial prairie. Ecology. 47, 88-96.
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Curtis, J. T. 1959. The Vegetation of Wisconsin: An Ordination of Plant Communities. Madison, University of Wisconsin Press.
Curtis, J.T. and G. Cottam . 1950. Antibiotic and auto toxic effects in prairie sunflower. Bulletin of the Torrey Botany Club, 77. 187-91.
Curtis, J.T. and M. L. Partch. 1948. Effect of fire on the competition between blue grass and certain prairie plants. The American Midland Naturalist, 39, 437-43.
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Howell. E. and F. Stearns. 1993 The Preservation, Management, and Restoration of Wisconsin Plant Communities: The Influence of John Curtis and His Students, pp. 57-66 IN John T. Curtis, Fifty Years of Wisconsin Plant Ecology, Edited by Fralish, J. S. and R. P. McIntosh, and O. L. Loucks, Wisconsin Academy of Sciences, Arts, and Letters, Madison, WI.
Kline, V.M. 1985. Response of sweet clover (Meliotus alba) and associated prairie vegetation of seven experimental burning and mowing regimes. In Proceedings of the 9th North American Prairie Conference. Ed G.K. Clambey and R. H. Pemble, pp. 149-152. Fargo: Tri-College Press.
Kline, Virginia M. 1993. John Curtis and the University of Wisconsin Arboretum, pp. 51-56 IN John T. Curtis, Fifty Years of Wisconsin Plant Ecology, Edited by Fralish, J. S. and R.P.McIntosh, and O. L. Loucks. Wisconsin Academy of Sciences, Arts, and Letters. Madison, WI.
Kline, V.M. and E.A. Howell. 1987. Prairies, pages 75-84. IN Restoration M.E.Gilpin, and J.D.Aber, editors. Cambridge University Press, Cambridge.
Kline, V. M. 1992. “The Long-Range Management Plan for Arboretum Ecological Communities.” University of Wisconsin-Madison Arboretum.
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McGaw, M. 2002. “The Response of Gray Dogwood (Cornus racemosa) to Prescribed Fire and the Effects of Invasion on Fuel Loading and Plant Community Composition at Curtis Prairie.” Master’s thesis. University of Wisconsin-Madison.
Peters, R. H. 1985 Global climate change: a challenge for restoration ecology. Restoration and Management Notes, 3, 62-67.
Sasche, N. D. 1974. “A Thousand Ages: The University of Wisconsin Arboretum.” Madison: Regents of the University of Wisconsin. Revised edition, originally published in 1965.
Snyder, T. A., III. 2004. “A Spatial Analysis of Grassland Species Richness in Curtis Prairie.” Master’s thesis University of Wisconsin Madison.
Sperry. T. M. 1984. Analysis of the University of Wisconsin-Madison prairie restoration project. In Proceedings of the 8th North American Prairie Conference. Ed. R. Brewer, pp140-147. Kalamazoo: Western Michigan University.
Sperry, T. M. 1990. “Report on the 1980 Curtis Prairie Survey for the University of Wisconsin-Madison Arboretum.” University of Wisconsin-Madison Arboretum.
Wegner, M. and J . Zedler. 2008. “Taking Stock: Status Report on our 75th Anniversary.” Arboretum Leaflets No. 18.
Wegner, M., P. Zedler, B. Herrick, and J. Zedler. 2008. “Curtis Prairie: 75-Year Old Restoration Research Site.” Arboretum Leaflets No. 16.