28th Annual Meeting and Symposium of the
Desert Tortoise Council, February 21-23, 2003
Abstracts

POSTER

New Technologies to Assess Vegetation Changes and to Revegetate Disturbances in the Mojave Desert

W. Kent Ostler and D. J. Hansen
Bechtel Nevada, P.O. Box 98521, M/S NTS 260 Las Vegas, NV 89193-8521

Research funded by the U.S. Department of Defense (DOD), U.S. Department of Energy (DOE), and the U.S. Environmental Protection Agency as part of the Strategic Environmental Research and Development Program evaluated novel techniques for collecting and processing high-resolution images in the Mojave Desert. New image-processing software makes it possible to accurately measure areas for total plant canopy cover and locations of up to four dominant shrub species in minutes compared to hours or days of fieldwork. Analysis shows that data from images are highly correlated with data from field sampling. Canopy cover and individual shrub parameters such as width, length, circumference, and shape factors can be readily measured yielding size distribution histograms and other statistical data on plant community structure. These techniques have been evaluated at Fort Irwin, California and the Nevada Test Site, Nevada. Results were compared among the new and conventional image processing techniques, including 1-meter pixel IKONOS satellite images. These techniques facilitate the development of georectified color-coded contour maps of shrub cover for use with Geographic Information System software and have been used at Fort Irwin to develop a cover map of the entire 1,100 square mile facility. They are valuable tools to accurately assess vegetation change and identify areas that require mitigation. The DOD has recognized the need to use lands on a sustainable basis so they are implementing measures to not only document disturbances but to investigate ways to mitigate the impact of their activities. Over 35% of all reclamation projects fail in arid environments because of harsh site conditions. Our research has focused on techniques to revegetate various levels of disturbance at Fort Irwin with an emphasis on low-cost techniques such as seeding. A series of field test plots have been implemented over the past four years and techniques have been developed to effectively restore these disturbances. Temperature and moisture are key factors that influence germination and establishment and these factors can be used to optimize seeding success. Treatment of seed to remove germination inhibitors can speed germination and increase seeding success. Mulches are effective at enhancing germination and retaining soil moisture as well as controlling erosion. User manuals that describe how to implement these technologies have been developed and are available upon request.

The work was supported by the Strategic Environmental Research and Development Program under work order AGRW74RDV90120347.