Shrub dieback in a semiarid ecosystem : The integration of remote sensing and geographic information systems for detecting vegetation change

During several years of high precipitation (1982-84) in the Great Basin region of the western U.S., many plant communities showed evidence of shrub dieback, primarily of shadscale (Atriplex confertifolia). The potential relationship between dieback and climatic change suggested the need for an objective test of the usefulness of remotely sensed data in detecting vegetation changes in a semiarid ecosystem. Two techniques were evaluated for their effectiveness in predicting shrub dieback. In the first technique, an unsupervised classification of Landsat Thematic Mapper (TM) data was used to predict the distribution of dieback. Spectral reflectance patterns associated with dieback were identified using a goodness-of-fit test.