Historical change in coastal sage scrub in southern California,USA in relation to fire frequency and air pollution |
| |
Authors: | Matt V Talluto Katharine N Suding |
| |
Institution: | (1) Western Riverside County MSHCP Biological Monitoring Program, 4500 Glenwood Drive, Building C, Riverside, CA 92501, USA;(2) Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697-2525, USA |
| |
Abstract: | Invasions resulting in the transformation of one ecosystem to another are an increasingly widespread phenomenon. While it
is clear that these conversions, particularly between grassland and shrubland systems, have severe consequences, it is often
less clear which factors are associated with these conversions. We resampled plots from the 1930s (Weislander VTMs) to test
whether two widely assumed factors, changes in fire frequency and nitrogen deposition, are associated with the conversion
of coastal sage scrublands to exotic grasslands in southern California. Over the 76-year period, coastal sage scrub cover
declined by 49%, being replaced predominantly by exotic grassland species. Grassland encroachment was positively correlated
with increased fire frequency and, in areas with low fire frequencies, air pollution (percent fossil carbon as indicated by
∂14C, likely correlated with nitrogen deposition). We conclude that increases in fire frequency and air pollution over the last
several decades in southern California may have facilitated the conversion of coastal sage shrubland to exotic grassland systems. |
| |
Keywords: | Mediterranean shrubland Coastal sage scrub Grassland encroachment Biological invasion Nitrogen deposition Fire frequency Air pollution Wieslander VTM |
本文献已被 SpringerLink 等数据库收录! |
|