Characterizing the spatial structure of vegetation communities in the Mojave Desert using geostatistical techniques

Geostatistical techniques are used to evaluate spatial characteristics of vegetation communities mapped within a portion of the Mojave Desert, California. Spatial structures of different vegetation communities were characterized using nugget, range and sill parameters of spherical model variograms. Model variograms reveal different vegetation communities have distinctive spatial properties that are quantified effectively by the parameters of these models. Model variograms were fit to experimental variograms calculated from plant width values of ground based vegetation data collected for 96 1000 x 2 m transects. The maximum model variogram range for all communities was 39 m, suggesting transects must be at least this long to classify them unambiguously into the communities currently recognized. Experimental variograms were calculated for all plants in each of eight mapped vegetation communities. The Bush Seepweed Series has a distinctively long range, for example, and the Creosote Bush Series has a distinctively high nugget and sill. These findings support use of high-resolution remote sensors and geostatistics for determining vegetation community structure. Spatial pattern information produced by these methods could improve broad scale vegetation classifications produced by low-resolution remote sensing systems. (C) 2000 Elsevier Science Ltd. All rights reserved.