J. T. Rotenberry, W. B. Kristan III, and M. V. Price.
2000. Distribution and community composition of birds and small mammals
in southern California coastal sage scrub. California Southcoast Ecoeregion
Conference, Pomona, CA.
Abstract. Between 1995-1997 we assessed distributions
of birds and small mammals using surveys conducted at 238 points grouped
into 22 sites throughout southern California coastal sage scrub (CSS) vegetation.
At each point we also measured local vegetation and landscape compositional
features. Analyses yielded several results. Although distinct at a regional
level (compared to other southern Californian vegetation types), CSS is
a heterogeneous plant community. Within CSS there were geographical gradients
in local vegetation structure and composition, as well as landscape-level
vegetation and land-use classification, mainly reflecting north-south and
east-west gradients in climate and topography. Several of these gradients
include patterns induced by human activities (e.g., exotic forbs and grasses,
urbanization). Individual animal species responded to these gradients,
with virtually all taxa showing significant associations with local, landscape,
or geographical variables. Likewise, several species also exhibited significant
urban "edge effects." However, the considerable heterogeneity
of individual responses precludes generalization. Patterns of bird and
mammal communities were associated with habitat variables, and were correlated
with each other; however, species richness of birds and small mammals were
uncorrelated. We conclude that a regional reserve system than spans the
range of CSS conditions and geographical areas will be necessary if we are
to preserve CSS species diverisity. However, any system of reserves cannot
rely on the local diversity of any single taxonomic group as an indicator
of appropriate design, but must be based on meeting the needs of multiple,
independent species' criteria.