Salmon River Ecosystem Earthworms Are the Most Essay

Excerpt from Essay :

Salmon River Ecosystem

Earthworms are the most tolerant and crawfish are the least tolerant of pollutions and reduced dissolved oxygen.

The loss of riparian areas from livestock grazing reduces the capacity of the river to clean itself. The addition of nitrogen from fertilizers causes acidization of the water. In addition to the polluted waterways, nitrogen contributes to smog and greenhouse gases, which are bad for human health and the economy. Costs are attributed to air pollution health and medical issues and cleanup efforts.

Deforestation can invite invasive plants into the ecosystem, reduce air quality around the rivers and streams, and increase the runoff, which further pollutes the water systems and decreases the level of dissolved oxygen in the water. The species that live in the aquatic ecosystems change as a result of the degraded water quality.

Ecosystems have the capacity to renew themselves and are able to overcome some pollution if the levels are not so high that they overcome the natural processes. When water moves through the soil in riparian forests and the wetlands, it is cleaned by the natural organisms and the physical filters of sand, gravel, root systems, and the like. Commercial agriculture deposits chemicals in the soil that is washed into the ecosystems, where some of it is eliminated and levels are reduced.

5. In order for salmon to be healthy in streams that are exposed to agricultural and industrial pollutants, it is necessary for the riparian forest conservation to be at 75 m or more, for pollution to remain above 4.0 parts per million (ppm), and for pollution levels to be at 3 or above. The best levels for maintaining the biodiversity of the Salmon River ecosystem are riparian forest conservation to be at 75 m or more, for pollution to remain above 4.25 parts per million (ppm), and for pollution levels to be at 2 or above. The crawfish and the fairy shrimp act as "marker" species for the riparian ecosystem (they are like the canaries introduced into mines),and when their numbers drop, it is an indication that the river sediment is carrying too much pollution and the fish are dying in higher numbers than is healthy for the ecosystem.

6. Organic farming could substantially reduce the amount of nitrate leaching that is contributing to nitrogen pollution. Research carried out by the Washington State University found that conventional fertilization techniques contributed to 4 to 5 times more nitrate leaching annually than did organic treatments.

Environmental Footprint

1. Use of services is the highest contributor to my environmental footprint, followed by food and shelter.

2. If everyone lived like me, it would take 4 and one/half earths to provide enough resources. A) My housing and transportation use does not include much alternative use of energy. As a result, my impact on the earth's climate due to dependence on oil and gas is greater than it might otherwise be. B) I don't greatly impact the health of ecosystems or biodiversity as I reuse, repurpose, and recycle. However, my home is built mostly of wood, which has a great initial impact on forests and ecosystems. C) I shop locally and garden seasonally, so my impact on human resources is less than it might otherwise be.

3. By eating fewer foods that come from animals, buying only recyclable products with less packaging, using energy efficient appliance and alternative sources of energy, and using public transportation instead of driving my car, I could reduce to 3.6 the number of earths needed to sustain my standard of living for everyone. If everyone reduced the services they require, which in this quiz are predominantly related to the gas, oil, and electricity consumption, the savings in terms of impact on the planet would be great. The forests would be able to regenerate, which would lead to cleaner water and air. In addition, growing food and eating food produced locally consumes much less petrocarbons and reduces spoilage and waste which go into landfills.

4. If I relocated to a place where the infrastructure provided better transportation options, I could significantly reduce my carbon footprint and also enhance my quality of life. Commuting is a strong detriment to living a higher quality lifestyle.

Land Use in Pinchot Lab


The research question for this study is how does land use changes, particularly deforestation and urban sprawl impact plant and animal communities, the predator / prey relationships, species diversity, and quality of life for humans in the suburban community of Pinchot? The hypothesis tested in the study was as follows: Ho (null hypothesis) = the percentage of fragmentation does not impact the sustainability of biodiversity and ecosystem services in the forest surrounding the community of Pinchot. Ha (alternative hypothesis) = fragmentation levels of 50% and 75% will not achieve sustainable levels of biodiversity and ecosystem services in the forest surrounding the community of Pinchot.


Two plant species and two animal species known to be ecologically important were considered under different conditions of fragmentation. The impact of fragmentation on the forest reserve and the community was explored through an iterative process of graphing the changes in plant and animal populations that occurred as the fragmentation percentages were changed in the model. Only one species was added at a time and the corresponding changes in species populations were recorded at the time of each change.


The computer modeling program indicated that under conditions of zero fragmentation, a desirable balance was achieved for all the species populations measured, and the predator / prey relationship was sustainable. Spiny firegrass (376) was held in check by a healthy bluebunch wheat flower growth (8778), which was sufficient to sustain a generous deer and elk population (2167), and a wolf population (462) sufficient to keep the herbivore populations within desirable bounds. An increase in fragmentation to 25% resulted in similarly sustainable populations and species balance (bluebunch wheat flower at 7993; deer and elk population at 3488, and wolf population at 416), with only a moderate undesirable increase in spiny firegrass (906). In contrast, modeling at the 50% fragmentation level resulted in these population counts (spiny firegrass at 5416; bluebunch wheat flower at 4837; deer and elk population at 4668, and wolf population at 235), and modeling at the 75% fragmentation level showed these population counts (spiny firegrass at 10114; bluebunch wheat flower at 811; deer and elk population at 9337, and wolf population at 5). Fragmentation at 75% is not sustainable for even the short-term, and fragmentation at 50% results in serious encroachment by the noxious weed known as spiny firegrass and a herbivore population that will overgraze and be particularly mobile -- crossing highways and feeding on landscape plants -- as they search for suitable food. The null hypothesis is rejected.

The wolf population was reduced to a threatened species level when fragmentation reached 75%. Changes to the herbivore population brought about a cascade of changes in the ecosystem as shown by the increase in spiny fireweed, and the decrease in the wolf population and the decrease in their preferred grazing plant in response to the increased numbers of deer and elk in the ecosystem. This cascade effect reached its apex at 75% fragmentation.


The noxious weed spiny fireweed benefitted the most from increased fragmentation, and although the deer and elk population increased, this is misleading since the herbivores would be dramatically underfed, since they overgraze the bluebunch wheat flower and the numbers of their natural predator had fallen to a low that would not keep the herd's numbers at healthy levels.

The findings support the importance of plant and animal species management in ecosystems that is both bottom-up and top-down. The keystone species in this ecosystem was not officially in the modeling program: human beings. The impact of fragmentation is a direct result of urban sprawl and the encroachment of ecological niches by people. After people, deer and elk are the keystone species because any substantive reduction or increase in their numbers results in dramatic changes in the other species on either trophic side of the cascade. Because wolves are less desirable -- from the human vantage point -- in the ecosystem, if their numbers are not sustained, then the natural culling by predators must be replaced by less natural culling by humans engaged in the sport of hunting. These dynamics evidence a top-down management approach. Regardless, the spiny fireweed plan population is likely to need some bottom-up management simply due to it toxicity and nuisance impacts. Spiny fireweed could conceivably be dragged and raked in the months before it turns dry, thereby reducing the wildfire hazard and its capacity to reproduce by seed, if not by runners.

This lab provided a clear example of a trophic cascade as shifts in the predator / prey relationship had far-reaching implications for the immediate forest area around Pinchot. An important result of this modeling was the demonstration that the species don't all follow the same pattern, shrinking as their niche shrinks or expanding as their niche expands. Some species,…

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