Mapping alpine vegetation using vegetation observations and topographic attributes

Local planning in mountain areas requires spatial information on site factors such as vegetation that is commonly lacking in rugged terrain. This study demonstrates a procedure for the efficient acquisition of a vegetation map using topographic attributes and nominal vegetation data sampled in the field. Topographic attributes were derived from a digital elevation model (DEM) and nominal vegetation data were reduced to normalised scores by detrended correspondence analysis (DCA). The procedure for mapping vegetation types addressed the relations between DCA scores and topographic attributes, spatial correlation of DCA scores and classification of predicted DCA scores based on a cluster analysis of DCA scores at observation locations. The modelled vegetation classes corresponded with the impression obtained in the field. We also showed that the final result is rather sensitive to which samples are included in the analysis.