?Great Plains Grasslands at the Millennium,? Symposium at the 1999 Society for Range Management Meeting, Omaha, NE, 24-25 February 1999. Proceedings in Great Plains Research 9(2) Spring 2000.
The Great Plains grasslands and prairies constitute what was once the largest vegetational unit in North America. With the settlement of the Great Plains, the grassland ecosystems have been converted to agriculture and other uses, both in public and private ownership. The grassland ecosystems of the Great Plains are faced with numerous stresses, including possible climate change, overgrazing, conversion to agriculture, invasion by non-native plants, and loss of riparian zones. A greater understanding of these ecosystems is needed to manage them sustainably and effectively. This is complicated by the fact that the Great Plains grasslands cross state and national boundaries and are made up of federal, state, and private lands.
National grasslands have received increased attention by the U.S. Forest Service (USFS) over the past several years. The Forest Service is dedicated to multiple-use management of National Grasslands for sustained yields of renewable resources such as water, forage, wildlife, and recreation. In 1996, the National Grasslands Management Review Action Plan targeted the need for science to understand and manage grassland ecosystems, and the importance of ensuring that information about the sustainable management of grasslands reaches the managers on the ground. To address these needs, the USFS, in partnership with ESA, the Society for Range Management, the USDA Agricultural Research Service, and the Centers for Great Plains Studies and Grasslands Studies at the University of Nebraska, Lincoln, organized a symposium, Great Plains Grasslands at the Millennium, to present a state-of-the-science review of current knowledge on topics of primary interest to grassland researchers, managers, and other interested parties. The symposium examined what is known about grassland ecosystems at the site, landscape, and regional levels, as well as economic and social factors. Other objectives included bridging the gap and building trust between researchers and those who need research information and providing a forum to better understand and communicate the value of grasslands.
Science and Management: James Saveland, Assistant Director for Research of the USFS Rocky Mountain Research Station emphasized the importance of having an integrated approach to the science and management of grasslands. He stressed the need for research and management to collaborate, as well as for collaboration among researchers in the biological, physical, and social sciences. Guy McPherson, The Nature Conservancy, discussed ways to improve linkages between science and management and asserted that both endeavors will benefit from increased understanding of each other?s goals. Scientists focus on general principles and on understanding relationships in systems, while managers are necessarily objective and site specific. We are at a critical juncture for the management of natural resources and scientists and managers must break down barriers and work together.
Setting the Stage: William Lauenroth, Colorado State University, set the stage for the symposium by discussing the global context for grasslands, the Great Plains concept, and the Central North American grassland region. The Central North America grassland region is unique globally, encompassing one of the largest contiguous areas of grasslands worldwide, with uniform gradients of topography, climate, and socio-political culture. Ingrid Burke, Colorado State University discussed the causes and consequences of land use patterns in the Great Plains. She found that environmental variables (precipitation, temperature, slope, and soil texture) can explain 80% of the variance in land use management. Dr. Burke noted the tension of land use management between cropland and rangeland and estimated the long-term, regional consequences of these land-use practices.
Clenton Ownsby, Kansas State University, reviewed possible impacts of changes in carbon dioxide, nitrogen, and climate in the central grassland region. His analysis suggested that elevated CO2 effects on grassland plants could include increased photosynthesis, improved water use efficiency, reduced nutrient status, and reduced respiration. Effects on natural ecosystems of the Great Plains are likely to include an increase in productivity in shortgrass prairies and changes in vegetation distribution and nutrient cycling.
Dan Flores, University of Montana, challenged the conception of the Great Plains as an unpopulated wilderness prior to European settlement. He noted that 350-400 generations of Native Americans have been impacting and actively managing the land of the Great Plains through fire, planting, water manipulation, and hunting practices.
Biodiversity and Conservation: The heterogenous landscape of the Great Plains is important in maintaining grassland biodiversity and ecosystem processes. Carolyn Hull Sieg, USFS Rocky Mountain Research Station, presented a discussion of biodiversity indicators of Great Plains rangeland sustainability. She noted that grassland systems have been severely impacted by land-use conversion, fragmentation, and degradation which have put species, ecosystems, and processes at risk and reduced ecosystem goods and services. A growing threat to grassland ecosystems are invasions by non-native species. Fred Smiens, Texas A&M University, provided a review of characteristics of invasive species and ecosystems susceptible to invasion.
The Nature Conservancy?s (TNC) conservation goal for grassland ecosystems of the Great Plains is to assure the long-term survival of viable native species and community types through the design and conservation of a portfolios of sites. Steve Chaplin presented TNC?s ecoregional planning process to identify and select suitable areas for conservation to protect all native community types, all rare species, and other selected declining species (e.g., grassland nesting birds, migratory shorebirds, neotropical migrants, big river fishes, area-sensitive species).
What little remains of the tallgrass prairies in the ?Prairie State? is highly fragmented. James Herkert, Illinois Endangered Species Protection Board, has been investigating the effects of habitat fragmentation on grassland birds. Problems associated with habitat fragmentation include habitat loss, an increase in edge effect, a decrease in patch size, and an increase in isolation, all of which can have negative impacts on ground-nesting birds. Land management practices outside of the Great Plains region also can influence patterns of ground-nesting birds in grasslands. Michael Carter, Colorado Bird Observatory, discussed the recent fate of grassland birds, conservation efforts, and cooperation efforts with private land owners both in the United States and Mexico.
Grazing: Grazing is an integral component to Great Plains grassland ecosystems which have evolved with grazing by large ungulates, particularly bison. Rodney Heitschmidt, USDA Agricultural Research Service, reviewed the ecological, economic, and social sustainability of grazing on the Great Plains. Given the history of grazing on the Great Plains, he proposed that well-managed grazing is ecologically sustainable, although not always economically viable or socially acceptable.
Stephen McCanny, Parks Canada, reminded the group that the Great Plains grasslands extend northward into Canada. Parks Canada has been investigating grazing impacts, the value of long-term rest in grassland conservation, and the consequences of leaving National Park lands ungrazed. Because it is important to graze conservation areas, bison are being returned to some National Parks to provide intensive grazing at a long return interval. Along with fire and some carefully managed cattle grazing, bison grazing will contribute to a dynamic and diverse landscape.
Three presentations examined the effects of bison and cattle grazing on grassland ecosystems. Al Steuter, The Nebraska Nature Conservancy, presented a comparison of the physiology, morphology, grazing strategies, and ecological impacts of bison and cattle. He found some differences in the influence of these species on plant community structure, which is further affected by adding fire to management strategies. But the bottom line is that both bison and cattle can convert forage effectively and can be managed to conserve soil, water, and biological resources.
David Hartnett, Kansas State University, summarized evidence from a study on population and community level effects of bison and cattle grazing on the tallgrass prairie at the Konza Prairie Long-Term Ecological Research site. This research found that grazing by large herbivores is fundamental for functioning of tallgrass prairie ecosystems. The differences in vegetation response to cattle and bison are not large and are primarily at the plant population level. In fact, plant populations and communities are more influenced by different management strategies than differences between bison and cattle.
Robert Hamilton, The Nature Conservancy Tallgrass Prairie Preserve, discussed the suitability of bison and/or cattle for grassland natural area management under several programmatic considerations (e.g., land base size, management style, surrounding land use, labor availability, institutional capability and goals). He presented case studies of three TNC preserves and how these considerations have affected the choice of management tools used (e.g., fire, cattle grazing, bison grazing, and combinations of these). Richard Hart, USDA Agricultural Research Service, discussed the implications for managers of recent research on impacts of bison and cattle grazing. He noted that land managers must use strategies that are appropriate for the class of livestock, the environment, and the economy.
Riparian Zones: Riparian zones are extremely important in Great Plains grasslands and have been greatly impacted by human activities. W. Carter Johnson, South Dakota State University, provided an overview of historical and ecological factors which control riparian zone dynamics on both large rivers and small streams. Dams and water diversions on the Missouri and Platte Rivers have had extensive impacts on the river dynamics, ecological processes, and vegetation communities of these systems. Small streams are more heavily impacted by local land uses and restoration of these small streams can improve the quality of rangelands.
Michael Scott, USGS Biological Resources Division, focused on the importance of natural disturbance regimes to riparian zones in his presentation on the effects of floods, ice, and cattle grazing on cottonwood demographics along a portion of the upper Missouri River in Montana. Successful recruitment of cottonwood requires infrequent high flows that deposit seedlings high enough on the bank to survive subsequent flooding and ice scouring. Grazing has been shown to reduce seedling densities, so grazing management can play an important role in the spatial occurrence and success of cottonwood establishment along this reach.
Socio-economic Factors: Outdoor recreation is becoming more popular and the Great Plains grasslands offer a multitude of opportunities for activities like walking, bird watching, and wildlife viewing. Ken Cordell, USFS Forestry Sciences Laboratory, presented trends in outdoor recreation in general and in the Great Plains. He noted that with an increasing demand for outdoor recreation and history and natural history based activities, we need to increase our understanding of the opportunities and impacts of these activities and do a better job of managing for them.
Mark Drabenstott, Federal Reserve Bank, discussed the economic future of the rural Great Plains. He noted that these communities are facing a large challenge and need to make informed decision about how to become economically viable. Four ways they can do this were presented: value-added agriculture, tourism, manufacturing, and white-collar services. The rural communities of the Great Plains are experiencing changes in population, organization, and physical environment. John Allen, University of Nebraska, suggested that centralization of government, the private sector, and agriculture are changing the relationships between individuals, communities, and sectors of our society. These changes to Great Plains rural communities in turn have impacts on the environment.
The economic, ecological, and social services provided by grasslands together form the basis for sustainability of rural communities. Jill Vaisey, Prairie Farm Rehabilitation Administration, Agriculture and Agri-Food Canada, presented a discussion of the economic, ecological, and cultural importance of grasslands in Canada?s three prairie provinces. Current issues impacting these lands include endangered species legislation, climate change, and economic diversification. These all have the potential to change the way the prairie grasslands are used, and so change the way they contribute to rural sustainability. Cornelia Butler Flora, North Central Regional Center for Rural Development, Iowa State University, proposed that by looking at economic, ecological, and social services provided by grasslands in an integrated approach, alternative methods of land use optimizing all three services can be developed. By recognizing the different resources present in grassland communities, citizens can individually and collectively make better decisions about how to invest those resources to create new resources.
Mary Peterson, Forest Supervisor, Nebraska National Forest, and Jerry Dodd, North Dakota State University, provided a synthesis of the symposium presentations which highlighted the strong link between science and management. Research involves inquiry while management involves application, but both are required to have real knowledge. Thus, partnerships are needed to enhance the joint advancement of research and management principles on the Great Plains grasslands.
Selected papers from the symposium have been published as a special issue of Great Plains Research (Volume 9, Number 2, Spring 2000). For more information contact Great Plains Research, 1215 Oldfather Hall, P.O. Box 880317, University of Nebraska-Lincoln, Lincoln, NE 68588-0317, 402-472-6970, fax: 402-472-0463, e-mail: firstname.lastname@example.org, website: http://www.unl.edu/plains/gpr.htm. The symposium was funded by the U.S. Forest Service under a grant to ESA and the development and printing of the proceedings was funded by a grant from the USDA Agricultural Research Service to ESA.
Dr. Elizabeth Stallman
Ecological Society of America