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The application of a remote sensing technique enabled vegetation abundance and dynamics to be studied in an area with a steep climatological gradient, ranging between Mediterranean and arid ecosystems. The methodological differences between field surveys and remote sensing are analysed and compared with regard to the type of information derived from them, and their relative accuracy and advantages. Four vegetation cover maps were then produced from the Landsat images of the 5 May 1991, 5 April 1992, 23 May 1992 and 10 July 1992. Using these images it was possible to study both the spatial variation of vegetation cover in this area, the seasonal changes which occurred between the winter and summer of 1992 and the changes between two corresponding seasons in 1991 and 1992, with extreme precipitation levels.

(C) 1996 Academic Press Limited