Alice Walker's Analysis
...o return to it original state after a disruptive influence (Britannica, 2003). The amount of diversity in a community is heavily affected by environmental factors such as food, light, heat and shelter (Otto, 1998). These elements determine how many types of different species can survive and can be supported in a community. Besides the elements listed, species diversity is also affected by each species niche, their interactions in the community and the changes that occur within the community. Niche Every organism has its own niche, which is an organismfs status or position within an ecosystem (Gates, 1998). An organismfs status can include its habitat, prey, predators, and how it nests and raises its offspring. If for some reason a species can no longer carry out its normal living patterns in its community, then that species and other factors in the community will be affected. Deer, who contribute to the species richness at Swiss Valley, can be used in describing niche. The preserve provides the perfect habitat for them, and offers plenty of food sources and water. Deer primarily feast on things like the leaves and twigs of trees and shrubs, acorns, beechnuts, herbs, mushrooms and fruit, majority of which are accessible in the preserve. (www.athensclarkecounty.com) Deer are pretty much safe in the preserve and can be quite abundant because there is nothing to balance out their population. Animals like cougars and wolves, the predators of deer, do not exist in the Swiss Valley community. Humans, who have become their arch enemy, are not allowed to hunt them in the preserve. For deer in Swiss Valley, carrying out their niche is not a problem. However, other species are not as lucky. Environmental factors, human activities, community interactions and changes play a major role in the reasons why some species are not able to uphold their positions in the community. Community Interactions The Food Web/Chain is gan important type of relationship within a communityh (Bates. 1998, p.517). It is defined as gthe sequence of organisms through which energy and materials are passed as the organisms eat and are eatenh (Bates. 1998, p.517). At Swiss Valley the food web is a vital interaction that occurs between the species in the preserve. An example of a food web in the preserver is plants¨ insects¨ toads¨ bats¨ hawk. Predation is an interaction in which predators control the population of their prey, but rarely eliminate them. Some species in the food web are in constant competition with each other and require some of the same resources. This is another way of controlling species abundance because one of the species will eventually out compete the other. Parasitism, Mutualism, Amensalism, and Commensalism. In many ecological communities, parasitic and mutual relationships occur. Many organisms act as a host to another organism. Other outcomes of these types of relationships include one of the organisms being harmed while the other benefits or one organism benefits while the other is unaffected. In Swiss Valley, fungi reside in many areas of the preserve. It is the perfect example of all the relationships listed above in the previous paragraph. Some forms of fungi are parasitic and grow in living trees (www.library.thinkquest.org). They produce mushrooms inside the tree trunk, and spores from the mushrooms spread to other trees (www.library.thinkquest.org). Other types of fungi can cause live bark and tree roots to rot (www.library.thinkquest.org). Not all fungi are harmful. Some fungi are actually beneficial to trees. The fungi and trees are dependant upon each other for certain nutrients. The dependency is so great that the absence of the fungi could stunt the growth of a new tree in that area ...