Intermountain plant community classification using Landsat TM and SPOT HRVdata

Rangeland plant communities of the Intermountain West differ in their ecolo gy and management requirements. Successful management of extensive areas at plant community-level resolution first requires an efficient, cost-effecti ve means of plant community classification and mapping. We evaluated the in fluence of image acquisition date and satellite imaging system on the accur acy of plant community maps created from multispectral satellite imagery of Reynolds Creek Experimental Watershed (RCEW) (234 km(2)) in southwestern I daho. Maps delineating 6 native and 2 non-native Intermountain plant commun ities were created from Landsat 5 TM and SPOT 3 HRV data using a maximum li kelihood classification procedure, Map accuracy was assessed using ground r eference points, Maps created from satellite data acquired during dry-down (early August) had higher overall accuracy ((x) over bar = 70.5%) than from data acquired during peak growth (early June) ((x) over bar = 54.4%), Over all accuracy of maps generated by Landsat ((x) over bar = 60.1%) and SPOT ( (x) over bar = 65.5%) were statistically similar, Given their broad spatial coverages (3,600 to 31,450 km(2) scene(-1), respectively), moderate resolu tions (20 to 30 m pixels, respectively), and potential to provide high clas sification accuracies, the SPOT 3 HRV and Landsat 5 TM satellite systems we re well-suited for classifying plant communities in the Reynolds Creek Wate rshed and similar areas of the Intermountain West. Practical procedures for plant community classification and map accuracy assessment are presented f or use by natural resource managers.