Masters Theses

Date of Award

12-1997

Degree Type

Thesis

Degree Name

Master of Science

Major

Ecology and Evolutionary Biology

Major Professor

John Rennie

Committee Members

Cliff Amundsen, Michael Huston

Abstract

Phase 2 of a landscape ecosystem classification (LEG) is described for the 43,800 hectares comprising the Foothills section (300 m to 610 m elevation) of the Tellico Ranger District of the Cherokee National Forest in eastern Tennessee. An LEG is a system of classification which integrates landform, soils, and vegetation. The major objective of Phase 2 is to identify ecologically equivalent site units in disturbed stands and compare those site units to site units identified in relatively undisturbed vegetation. Identification of site units in relatively undisturbed vegetation has been completed in Phase 1 of the LEG for the Foothills section. Vegetation, landform, and soils data were collected from 72 0.04 ha plots. Stands were sampled from two age classes, 21-40 years and 61-80 years. Vegetative data was summarized by species for each age class and was analyzed using indirect and direct gradient analysis techniques. Indirect gradient analysis included detrended correspondence analysis using DECOR AN A and two-way indicator species analysis using TWINSPAN. Stepwise discriminant analysis was used to determine which environmental variables contributed most to differentiation among the site units. Direct gradient analysis was performed using detrended canonical correspondence analysis. Indirect and direct gradient analysis results were compared. Six site units were identified in the 21-40 age class; 1) Chestnut Oak- Red Maple-Virginia Pine, 2) Virginia Pine, 3) Mixed Pine, 4) White Pine-Tulip Poplar, 5) White Pine-Tulip Poplar Mixed Oak understory, 6) Hickory-Mixed Oak. The environmental variables which contributed most to the site unit classification were terrain shape index (a measure of plot shape), landform index (a measure of protection), slope position, and elevation. Six site units were also identified in the 61-80 age class: 1)Red Maple-Scarlet Oak-Yellow Pine, 2) Chestnut Oak-Hickory. 3) Red Maple-Mixed Oak, 4) Hemlock-Mixed Oak, 5) Hemlock-Hickory. 6) Red Maple-Hickory-Tulip Poplar. The environmental variables which contributed most to the classification of the site units were landform index and elevation. For each age class, a model was developed to indicate the ranges of the environmental variables where site units are most likely to occur. Site units and the ranges of environmental variables were compared among the 21-40 age class, 61-80 age class, and steady state vegetation identified in Phase 1 of the LEG. These comparisons identified successional trends.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS