Document: MAN-3-67-3

Riparian vegetation succession along the Cosumnes River, California.

TU, M.*

University of California, Davis, CA 95616 ¹

Abstract:
Vegetation dynamics of a forest riparian system was studied from 1995 to 1998 in California's Central Valley. Non-metric multidimensional scaling revealed that each of four sampled (variable-aged) sites can be delimited by species composition alone into distinct successional stages.The establishment of all vascular plant species was followed on a newly formed sandbar, created following an intentional levee breach onto an abandoned field, from 1996 to 1998 using belt-transects. There was an overall trend towards greater species diversity and a divergence of vegetation composition (increase in permanent plot dissimilarity) with time. Successional species were primarily native woody plants, and equal numbers of native and exotic herbs. Comparing the sandbar site with older forests (established 11 to 14, 30 to 39, and 60 to 64 years earlier), the oldest stand had higher total species diversity than intermediate stands, but not different than that of the sandbar stage of succession. Native species diversity, however, increased over time and contributed more and more to total diversity. Relative cover of native species also increased with time. The year-to-year fluctuations of the abundant native annuals Bidens frondosa and Xanthium strumarium however, may be a confounding factor in the understanding of the dynamics of this system.

Keywords: riparian; dissimilarity; diversity; plant succession

This abstract is being presented at: 9:15 AM in session:
Oral Session #20: Riparian Ecology.