Abstract & Conceptual Questions Land and Life on the North American Prairie by Robert E. Ford Jump Point: About the Case Study Case Study Abstract Conceptual Questions How to Order the Casebook About the Case Study This case study abstract is from: GeoSystems Today: an Interactive Casebook. Each printed case (in the book) starts with a list of Questions to be Explored followed by Key Learning Outcomes. An Overview and Background section then introduces the essential geosciences concepts and issues followed by a section entitled The Human Dimension. The latter section presents an integrated perspective on the "nature-society" linkages and policy implications of the case. At the end are Some Recommended Readings for more in-depth study. After you study the basic written text, and possibly do some background reading in a related textbook such as The Blue Planet: An Introduction to Earth System Science, you should take an online Virtual Tour and do the Self-Study Exercise found at the end of each case. At this point you should be ready to discuss the Conceptual Questions at the end of each case (they are repeated here as well). A suggestion–though the conceptual questions could be discussed with only the textual material as background, exploration of the online material as well would deepen your understanding and capacity to contribute meaningfully to a discussion. You are also strongly encouraged to explore some of the advanced material listed under More Activities and Learning Resources. How much more to explore is only limited by your time, interest, ingenuity and motivation! Back to Top Case Abstract Location In this learning activity you will explore the grassland biome of the world and particularly that portion of midlatitude North America known as the Great Plains or Mid-Continent Prairie. There are other important midlatitude, subtropical, and tropical grasslands each with their own distinct history, ecology and local names. These include, for example the Pampas in South America, the Veld in South Africa, the Chernozems of Ukraine and Belorus and the savannas and steppes of the arid and semi-arid tropics. Primary Objectives The primary objectives of this case study are to: 1. introduce students to the underlying biophysical forces which characterize the global distribution of the grassland biome including the western rangelands and prairies of North America, 2. consider in more detail how the Prairie/Great Plains ecoregion of Mid-Continent North America has evolved through time, particularly during the Holocene, and, 3. explore some of the complex issues of land degradation and ecosystem management–particularly soil erosion, groundwater extraction and biodiversity loss affecting the region. The key question to be considered is the following: have the limits to sustainable development been breached? If so, how can we measure, monitor and mitigate the forces which produce land degradation and particularly topsoil and biodiversity loss in the world’s grasslands and rangelands and can we restore these ecosystems? Background In simple terms, the grassland biome includes a broad collection of ecosystems that exist between the drier margins of the forest margin and the edge of the desert. Grasslands, like other biomes, share certain common ecological characteristics due primarily to adaptation to soil, water, climate, fire and other constraints on plant growth. Precipitation effectiveness, a critical indicator of whether a given area will support a forest, grassland, desert or tundra, is most frequently estimated by measuring evapotranspiration and computing an annual water budget for a given area. Temperature and seasonal solar relationships; i.e. orientation toward the sun is also important because both temperature and precipitation conditions together determine general plant growth conditions. Therefore, conditions that favor grasslands over forest also vary as one changes elevation or where fire is more frequent. The Great Plains Grasslands Ecoregion in North America, also known as the Mid-Continent Prairie, illustrates well the tight link that exists between landscape evolution, geology, ecology, climate and natural resource availability and productivity which produces the ecosystems of a biome. While some observed features and processes reflect shorter or longer term natural fluctuations in the biophysical environment resulting from climate change, other processes can be attributed to human impact such as land use and land cover change or economic activity under varying technological conditions. Human use of fire, for instance, dating back to prehistory has greatly expanded the grasslands. Later, grazing by domesticated animals further altered the grasslands. In fact, in both the tropical savanna grasslands and in the midlatitude steppes and prairies, anthropic influences on both the structure and species composition of the grasslands has been very significant. Grasslands around the world are not alike though grasslands in like environments often share similar physiognomic characteristics. Their appearance reflects constant adaptation of plant formations and individual species to drought, fire, animal predation, climate change and human impact. Grasslands also exhibit great species diversity and support some of the most complex food webs of any ecosystem on Earth. Picture, for instance, the tremendous animal species diversity and awe-inspiring competition for resources along the trophic chain in the savannas of the Serengeti Plain in Tanzania. This gives just an inkling of what the North American Great Plains environment must have been like during wetter phases of glacial times when the Mastadon and Sabre-Tooth Tiger roamed among millions of Bison and other now extinct creatures. Botanically the grasslands biome is dominated by grasses but the story is actually much more complex. Undisturbed natural grasslands include many non-grass species, including forbs as well as woody shrubs, and trees. The structure of grassland vegetation formations is also very complex. There is complexity in how species are organized spatially varying from north to south as well as from east to west. In North America, one can observe a whole range from short-grass steppes, scrublands and prairies on the dry arid boundary to tall-grass prairies, savannas, woodlands and forests on the humid boundary. Grasslands or prairies rarely exist in continuous stretches. More often they are organized as a mosaic of patches interspersed between gallery forests along streams or among other plant formations depending on local soil-water-climate conditions. This patchiness is particularly pronounced where there is greater local relief, where the underlying geology is complex, where fire has not been controlled, along the forest or desert boundary zone, and where unique climatic conditions related to glacial history have created locally unusual edaphic or soil-water conditions. Examples of the latter are the sloughs of North Dakota or bogs of Wisconsin and Minnesota. Many are kettles and kames, a type of glacial feature common to outwash till plains. These wetlands are extremely important breeding grounds for water birds such as ducks and geese and they frequently feed on plants growing in adjacent grasslands, scrub or woodlands. In sum, the grassland ecosystem is a much more diverse landscape than many expect. The prairie, in fact, has a unique beauty and appeal that has inspired many great natural history writers and even novelists and historians, including Aldo Leopold (1949) A Sand County Almanac ( New York: Oxford University Press), Diane Quantic (1995) The Nature of the Place: a Study of the Great Plains Fiction (Lincoln, NE: University of Nebraska Press), and Wilbur R. Jacobs (1994) On Turner’s Trail: 100 Years of Writing Western History (Lawrence, Kansas: University Press of Kansas). Agriculture and the Corn Belt The North American tall-grass prairie and particularly the subregion known as the Corn Belt is by far the world’s greatest producer of cereals such as maize and sorghum (milo). Some of the cereals are eaten directly by humans but much is fed to beef cattle and pigs. The short-grass prairie also produces vast amounts of spring and winter wheat. And on the drier margins of the High Plains and in the western uplands and mountains cattle and sheep are still grazed on the "open range" or rangelands. Today, human impacts in the Corn Belt, resulting from the attempted management of entire drainage basins or ecosystems and the massive mining of topsoil and groundwater resources by industrial agriculture and animal husbandry rivals if not surpasses what natural forces or Early Man did in the past. A few small "restored" prairies and National Grasslands remain but nothing rivals the vast sea of grass that existed before the sod-busters and cattlemen arrived. (You are encouraged to explore the web-based material produced by the National Homestead Monument and other sites such as the Illinois Science Museum which depicts the pioneer history of the Great Plains. See also Bogue, Allan G. 1994. From Prairie to Corn Belt: Farming on the Illinois and Iowa Prairies in the 19 th Century. Ames, IA.: Iowa State University Press; Jacobs, Wilbur R. 1994. On Turner’s Trail: 100 Years of Writing Western History (Lawrence, Kansas: University Press of Kansas). But the problem is even more complex than just managing basic soil and water resources for farmers and ranchers–the prairies and rangelands are not just for producing beef and pork. Prairies are increasingly important recreational resources as well that provide access to open space and wilderness for people living in urban regions. And they are critical reserves for preserving the genetic biodiversity that is essential for modern industrial agriculture and medicine. On both the High Plains and in adjacent mountain lands, management of "non-traditional" natural resources such as open space, watersheds and wilderness increasingly competes with older extractive industries such as ranching, mining, and agricultural production. This has increased the level of conflict between competing interest groups. Solving and managing these complex issues (ecosystem management) requires a broad perspective by many specialists working together in teams and using multiple tools and techniques. Learning to do this type of integrative and interdisciplinary study is what Earth Systems Science (ESS) is all about. Monitoring and Mitigating Land Degradation One of the most critical problems in monitoring and mitigating land degradation, a primary theme in GEC (Global Environmental Change) research, is the lack of high quality spatial and temporal information about climate, soil and vegetation patterns, animal distributions and migrations, groundwater and of course, human impacts on land use cover change (LUCC). The physical and human complexities of these problems, and their seriousness, force us to look for tools that are cheaper, more timely, effective and much more extensive in their reach. Hence, the need and opportunities afforded by the use of modern "hi-tech" tools such as GIS (geographical information systems) and GPS (global positioning systems) to map, monitor, manage and mitigate the driving forces of global change that are accelerating land degradation, biodiversity loss, erosion, deforestation, and land use cover change in the region. You can learn more about using these "new tools" in Case 4. Back to Top Conceptual Questions The key questions for you to examine are the following: What are the principal natural resource endowments and physical features of the Great Plains/Corn Belt/Tall-grass Prairie landscape that can be traced back to its complex geologic and Pleistocene history? Can you explain the processes that contributed to that complex history? What do you think are the answers to some of the troubling resource management and ecological issues raised in the case that relate to human-environment interaction as well as the human dimensions of global change? Is the achievement of "sustainability" a viable and doable scenario for the region and peoples who live there? What is the potential of alternative methods of farming as well as urban-oriented uses of the land that will restore a balance between soil-loss and soil-formation as well as biodiversity loss? Can land that has been abused be truly restored? What are some of the potential costs and barriers that impede ecosystem restoration activities in the region? Back to Top How to Order the Casebook You can order the printed casebook and see other related resources from John Wiley & Sons, Inc at the following URL: www.wiley.com/college/ Back to Top GO TO THE VIRTUAL TOURS AND EXERCISES Created 7 March 1999 .