How Was the Vegetation Map Created?
Creation of the vegetation map was a complex process, with many phases, through GIS. The vegetation of the project area is incredibly diverse due to changes in elevation, and diverse bedrock, soil types, and moisture regimes within the area: grasslands and chaparral in the west, forests in the mid-elevations, alpine zones in the high elevations, and sagebrush communities in the east. The first phase was to acquire custom aerial photography for the area to be mapped. More than 1,500 photos were taken, and each one had to be individually analyzed. Later phases included delineating polygons (areas) of distinct vegetation types, establishment of ecological plots to relate the aerial photographs to on-the-ground data, development of a classification scheme to assign names to those polygons, and accuracy assessment of the final product. There were 220 types identified over 1.4 million acres as map possibilities, although not all are vegetation types. The vegetation map of Yosemite is a multi
