Abstract

The purpose of this study, which was undertaken from September, 1977 through June, 1978 was to survey the response of perennial vegetation to General Patton's World War II armored maneuvers. This information will be used to help construct a basis for predicting recovery rates on the effects of off-road vehicle impacts in the California Desert Conservation Area (CDCA). These impacts were assessed in three usage categories: tank tracks in the maneuvers areas; roadways, which were used primarily by jeeps and trucks; and tent areas, cleared areas in which tents and other semi-permanent structures were erected. The data generated from these areas was compared to data gathered from adjacent undisturbed control sites.

The methods employed were temporally separated series of aerial photographs analyzed for density and cover, supplemented by on-site ground disturbance and control measurements of these parameters. From these values diversity, stability, productivity, community quality indices, and Jaccard's coefficient of similarity were calculated.

Results indicate that the maneuvers had a negative effect on the perennial vegetation, the degree of impact varying with habitat conditions and the various use categories. This concentrated, distant past use even with 37 years allowed for recovery still shows an overall mean plant cover reduction of fifty percent. Ground measurements of percent species composition show differences between disturbed and control sites in addition to the reduction in cover indicating an alteration of plant diversity and stability. Both aerial photographic and ground transect analyses indicate a marked reduction of perennial vegetation as a result of the initial maneuvers and a relatively slow recovery rate, varying with use intensity, physiognomic, and topographic characteristics.

Key words: perennial vegetation responses, General Patton's tank maneuvers sites, aerial photographic analyses, on-site ground transect analyses, density, cover, stability, diversity, productivity, tank tracks, roadways, tent areas, recovery rates.

LLU Discipline

Biology

Department

Biology

School

Graduate School

First Advisor

Earl W. Lathrop

Second Advisor

Conrad D. Clausen

Third Advisor

C. Douglas Eddleman

Degree Name

Master of Arts (MA)

Degree Level

M.A.

Year Degree Awarded

1979

Date (Title Page)

8-1979

Language

English

Library of Congress/MESH Subject Headings

Desert ecology -- California; Ecological surveys -- California

Type

Thesis

Page Count

viii; 85

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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