Soil Analysis

We took three soil samples: a sample near the water, a sample in the grassy area, and a sample near the dead log (refer to the map for further assistance). The color of the soil sample taken near the water is a rich dark brown; the soil is moisture opulent due to its proximity to the creek, the water filters through and envelopes the soil. The structure of the soil sample is sandy loam. The nitrogen level of the soil is low, the potassium level is medium, and the phosphorus level is low. High levels of nitrogen in soil are rare, unless the soil is commercial fertilizer. The source of potassium was most likely obtained from the weathering and chemical breakdown of rock; the area where the soil sample was taken contained several large rocks. The lack of phosphorus in the soil is common. Although the main source of phosphorus comes from the weathering of rock, phosphorus is scarce in the environment and the area contained many large trees, which blocked much rain and weather.

The color of the soil sample taken in the grassy area is brown and slightly dry. The structure of the soil is sandy clay. The nitrogen level of the soil is low, the phosphorus level is medium, and the potassium level is high. The medium level of phosphorus in the soil is due to the weathering of rocks. The grassy area contained rocks and was more exposed to the open sky, which increases the likelihood of successful rock weathering. Additionally the high level of potassium is due to rock weathering.

The color of the soil sample taken near the dead log is rich and black. The soil is rich in organic matter and obtains its dark color due to the nutrient breakdown of the dead log. The structure of the soil is. The potassium level of the soil is medium, the nitrogen level is low, and the phosphorus level is medium. The medium levels of potassium and phosphorus probably come from the dead log nearby. The nutrients from the log are broken down by detritivores and released into the soil.

A Possible Food Web

Works Cited

We would like to acknowledge the following:

Wikipedia, the free encyclopedia. 2007. 22 Oct. 2007 .

What Bird.com. 22 Oct. 2007 .

Google. 22 Oct. 2007 .

Blake Sills for teaching us how to do the things necessary to complete the project.

Bird's-Eye-View Map of Quadrat

Oak Trees of the Quadrat and Determining Carrying Capacity

There are six oak trees in our quadrant. This total and the total of acorns produced in a year determine the carrying capacity of the quadrant. If the keystone species of the quadrat has a large food intake then the total number of that species will be considerably low, along with the other acorn eating species, because the individuals of the species compete for food. If the keystone species is a species that has a low food intake then there would be a larger population of that species and of other acorn eating species. There must be a balanced ratio between mast producing trees and keystone predators to supply enough food to support the ecosystem of the quadrat. Overall, the amount of acorns produced by these six oak trees determines the carrying capacity in the quadrat.

Organism Relationships

The organisms (animals and plants) of the quadrat interact with one another and share resources. The mast producing trees of the quadrat, such as the oak tree, produce acorns to feed the squirrels and birds. The feces discharged from the squirrels and birds enters the soil and becomes detritus. The detritivores eat the dead leaves, rotting wood and feces in the soil and enrich the soil by breaking down the nutrients in the detritus. The soil is then enriched and able to produce more mast producing trees and plants, which feed the animals.

The creek provides an aboitic habitat for water plants and animals, such as the Mallard ducks we found. The Rusty blackbirds we discovered in our quadrat eat, as one of their food sources, the water bugs off the surface of the water. Underneath rocks is also an aboitic habitat for living organisms, such as ants and termites, who prefer the dark and the protection of the underside of the rock. Dead logs are also home to termites, ants, slugs, and beetles. The living trees of the quadrat provide shelter to squirrels, birds and spiders.

The animals of the quadrat all compete for shared food sources produced by oak trees and other mast producing trees. There is a symbiotic relationship within the quadrat. The squirrels, birds and other animals that eat acorns, share mutualism with the mast producing trees. The trees produce food for the animals and the feces of the animals, in the long run, helps to replenish the soil and allow for more trees to grow.

Species Diversity, The Dominant Species and The Keystone Species

Tree diversity: 3(2) + 7(6) + 4(3) + 1(0) + 1(0) / 16(15) = .209 --> .21
*3 = White Ash trees
7 = American Elm trees
4 = American White Birch trees
1 = Norway Maple trees
1 = American Tulip trees


There does not seem to be a dominant species in our quadrat. If there were one, that title would be shared between the Rusty Blackbird (Euphagus carolinus) and the Eastern Gray Squirrel (Sciurus carolinensis). Both eat acorns, but the Rusty Blackbird also eats bugs. Though, this would not affect the squirrels’ diet. The Rusty Black and the Eastern Gray Squirrel have to compete for acorns, but the squirrels would probably win out because they are more accustomed to foraging for acorns (it is their main food source).

The keystone species in our quadrat is the termite. As detrivores, they eat dead leaves and dead wood and turn the waste into something useful. The trees use the detrivores’ waste for nutrients, so the termites help keep the trees strong. Those same trees provide acorns for both the birds and the squirrels. Sometimes, the termites eat hollows into trees where squirrels and birds can make comfortable homes for themselves. The earthworm (of the Order Opisthopora) would be a close second. Though it processes detritus as well as dead animals, it does not eat through wood to indirectly make homes for the birds and squirrels.