The Tallgrass Prairies of Northwestern Arkansas, Coursework Example

When Europeans first encountered the Great Prairies of America’s Midwest, they were amazed at the endless sea of grasses they encountered.  The grasslands, or prairies as they are known, spread from Appalachia all the way to the Rocky Mountains, from Canada down to Mexico.  The grasslands were dominated by short, medium or tall grasses. Northwest Arkansas was home to the tall grass prairies, grass that would grow to about 5 or 6 feet in height.  Tall grass prairies once covered over 100,000 acres in the northwestern portion of Arkansas.  Today, they have all but vanished. “Today, less than 1% of the original tallgrass prairie remains.” (Todd 20) Due to conservation efforts a small piece of the tall grass prairie is coming back to life.  “The Baker Prairie Natural Area is a remnant of what was once a 5,000 acre tall grass prairie located west and south of present day Harrison, Arkansas.  It is the largest known remnant of Ozark Mountain prairie on a chert substrate.” (Natural Heritage 2010)  “Prairie restoration, however, is not a simple matter of establishing a prescribed mix of warm-season grasses and forbs.” (Todd 20) In order for conservation and restoration projects on ecosystems to succeed, an in depth knowledge of how the ecosystem functions is necessary.

Tallgrass Prairies occur in the wettest areas of the grasslands, but still thrive in conditions where there are prolonged dry seasons and little rainfall.  Grassland soil is rich and deep, making it excellent for agriculture which is the main reason that these ecosystems are under serious threat.  One of the most prominent features of grasslands is that they are totally devoid of trees, except in areas along creek or river beds.  Major biotic features of grasslands are wild grasses and grazing herbivores.  Insects, birds, reptiles, and micro organisms all co-exist in the grasses that cover the landscape.

The grassland ecosystem is a climax community that maintains a delicate balance through its relationship with fire.  Grasslands tend to be too dry to maintain trees and too wet to turn to desert.  Short grass prairies are the driest of the grasslands, and tall grass prairies are supported by a moister climate.  However, in disturbed grasslands it has been evident that the land can indeed support trees if they are given the opportunity to grow.  The original lack of trees, therefore, posed a problem to early ecologists.  After study, it was determined that fire played a major role in the maintenance of the grassland system. On the border between forest and grassland, trees would entrench onto the territory of the grassland by the dispersal of airborne and animal borne seeds.  Seeds would have trouble taking root because of the thick mass of roots that forms a matt on the surface of the prairie.  However, some seeds would eventually take hold and germinate.  As the tree grows, it will produce shade that will kill the grasses underneath it.  Luckily for the grasses, fires started in dry seasons from lightening would periodically rip across the prairie, killing any trees that had managed to take hold.  The grasses would, however, survive because most of their biomass exists below the surface and is impervious to the fires heat.  Once the rains would come, the grass would rise again, but not so the tree.

Grazing herbivores are also a major part of the maintenance of the grassland climax community. Native grazing herbivores like buffalo would eat the grassed down to just above the substrate.  This will trigger the grass to send up new shoots, starting a new cycle of reproduction.  Below the substrate is where most of the biomass of the prairie is located.  Micro organisms, worms and various burrowing animals live in the soil, enriching it through biological processes.  The rich soil of the prairie is what has attracted farmers.  Farmers have been utilizing the rich soils of America’s Midwest prairies for centuries.  Food plants such as corn and wheat flourish in the rich prairie soil once the tall grasses are removed.  Once the complex roots of the grasses that held the soil into place are gone, erosion becomes a major problem for these ecosystems.  Food crops such as corn and wheat have relatively small and shallow root systems, with most of their biomass being aboveground.  When dry winds blow across the prairie, as they often do, they take the top soil with them.

Knowing the natural parameters under which tall grass prairie flourished has allowed conservation efforts to be implemented at Harnesses Prairie, a restored tallgrass prairie near the virgin tallgrass remnant Baker’s Prairie. In conjunction with the U.S. Natural Resources Conservation Service and the Wildlife Habitat Incentive Program, Mel Harness and his family began restoration work on 20 acres of tilled farmland that they owned near Bakers Prairie in northwestern Arkansas. The project included site preparation by ridding the area of non-native grasses and reseeding using a mixture of about 75 native tallgrass seeds.   In order for the project to maintain success, it may be necessary to periodically maintain controlled burns in order to replicate natural conditions, since naturally occurring wildfires are generally not allowed to burn naturally, due to danger to humans and property.

References

Harrod, Jay. (2005, October) Bringing back the natural state of things: An Arkansas family restores a tall-grass prairie.  The Nature Conservatory Web. Retrieved 4 May 2010 fro http://www.nature.org/wherewework/northamerica/states/arkansas/preserves/art24997.html

Todd, T.C., Powers, T.O., Mullin, P.G. (2005, June 5) Sentinel nematodes of land-use change and resortation in tallgrass prairie. The Journal of Nematology 38(1): 20-27. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2586438/