We also quantified the current ownership and management status of the coastal sage scrub type, its dominant species, and common species combinations. However, species distribution boundaries showed very little coincidence and the pattern of species combinations was more suggestive of broad compositional gradients than of well defined types or geographic assemblages. All coastal scrub species and species complexes were mapped predominantly on private lands, many of which are under intense pressure from urban expansion. For example, practically all landscapes dominated by Salvia leucophylla are private lands of the western Transverse ranges, north of the current range of the gnatcatcher. Divisive information classification of 598 landscapes in which coastal sage scrub is a primary or secondary vegetation type, based on species composition data.
Boxes record the number of samples in each node of the tree.
The height of the horizontal lines indicates the information captured by that split. Composite distribution of 12 classes of coastal sage scrub identified by divisive information analysis displayed over a shaded relief image. Bayesian classifier of communities from species assemblages An inevitable problem in compiling regional vegetation databases is discrepancies among vegetation classification schemes. As described above, for the California Gap Analysis we stored preclassified data on vegetation cover and species composition in order to maintain as much flexibility as possible in relating our data to other vegetation maps. Thus we derive a vegetation class from a list of dominant species occurring in a landscape mosaic.