Soil prrovides water, minerals, and anchorage for plants. In this experiment we plan to analyze soil in various locations in the Western Forests. From this analysis, we will determine if certain characteristics in the soil affect the density of tree growth within various forest settings. There have been studies done in the past, such as those of Thomas L. Kieft(and associates)regarding the nutritional qualities of soil comosition and how those qualities related to the local plant growth. Nitrogen compounds are essential for plants according to the Water Quality Association in 1996. The levels of pH will also be tested because according to Harry White in 1997, "Root development is dependent on soil properties such as water content, pH and the concentrations of essential mineral elements. Soil tends to become acidic and due to this acidity, the soil chemically binds and inhibits bacterial production of nitrates, although the level of this effect is dependent on soil structure. Clay on the other hand tends to possess negative ions(anions) that attract and hold soluble nutrient cations(positively charged ions), preventing their loss through runoff, and this complex exchange of ions in the root structure of plants facilitate the withdrawal of nutrients in soils of pH levels 5 or higher. Nitrates are a critical factor in the development of leaf area or photosynthetic surface, thus dictating the amount of photosynthate available for plant growth and reproduction." We will study the pH levels in accordance with Harry White's idea that acidity of soil can affect the nutrient levels in soil and therfore affect tree growth which relies on such nutrients. We will examine the effect that these characteristics of soil quality in our samples:nitrates & phosphates,pH levels, and %oxygen/CO2levels. We propose that there will be a higher density of tree growth(count of trees in a certain area)in areas that are abundant in the characteristics mentioned above.
Methods&Materials:
Marking each section with string, we will measure strategic areas of the forest that measure 20 by 20 feet so that we may obtain four samples to then average and receive a more representative figure for the sample within each area. We will pick these areas by their location in relation to the amount of trees growing in the area(ie. using 2 different samples of soil, one from an area with few trees and on from an area with many trees, from wet soil). From those areas we will obtain 4 samples to be tested for soil's composition. We will obtain these samples through use of a soil bore. Each sample will be taken from a uniform depth(undetermined as of 10/12/97)so we can accurately compare soil to other like samples. We will take samples twice per week(once if twice is not needed). We will place the sampled soil into containers and bring them back to Boyd Hall to be tested using soil testing kits, litmus paper, and distilled water. The characteristics we are testing for should tell us whether or not the soil composition is affecting tree growth in the area tested. We will record the results in the data sections to be made when results are obtained.
Class Participation:
Class will venture in the woods to obtain samples from previously amrked area so that they can experience the collecting of soil and understand how the experiment will be carried out. We will also try to explain the significance of this experiment in class so that the class will better understand the experiment before they collect their samples.
Results: (not yet available)
*** map of tested area locations will be provided ***
Data: (will be added as collected)
Works Cited
1.Kieft, Thomas L., et al. eds. "Nutritional Cycling Studies: Carbon and Nitrogen Dynamics." Netscape: http;//sevilleta.unm.edu/soil/fpscnmetadata.shtml, 1994.
2.White, Harry. "The Forest Cycle: Forest Patterns and Processess." Netscape: http://www.connix.com/~harry/forest.htm, 1997.
3.Water Quality Association. "Water Quality Basics: Nitrates and Nitrites." http://(in process of trying to find again!!!), 1996.
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