Love, Byron , Foley, Patrick .
Nonnative Plants and Bees Meet the Natives Along the American and Cosumnes Rivers in Sacramento County.
Nonnative flowering plants and bees form an important community component in California ecosystems, especially in the Central Valley. Although badly outnumbered, native plants remain, as do many native bees. Competition occurs among plants and among bees; mutualism is common between bees and plants, even between nonnative plants and native bees, but some nonnative bees may give an edge to nonnative plants. Complex ecological interactions ensue, leading to bee community distributions which are still largely unstudied. This paper reports a study to investigate bee communities at 8 disturbed riparian sites in Californiaís Central Valley, 4 on the lower Cosumnes River, and 4 on the lower American River. Pan trapping (using the Bee Inventory Plot protocol) was supplemented by the aerial netting of bees on specific plants. Floral resources were estimated for each site. 64 flowering plant species and 122 bee species were found. Of these, five bee species and the great majority of plants were nonnative. The nonnative bees tended to be locally abundant but not evenly distributed. Bee preferences for native and nonnative plants were examined using ordination techniques. The Cosumnes River sites accounted for two-thirds of the 8,000 bees collected. Nonnative plants extend the resource availability phenology for both native and nonnative bees, but not necessarily to the same extent. Local bee competition, mediated in part by plant distribution, may lead to a mild form of Diamondís checkerboard community pattern. The conservation implications of the study are manifold, including the importance of maintaining native plant diversity at a local level.
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1 - California State University, Sacramento, Biological Sciences, 6000 J Street, Sacramento, CA, 95819-6077, USA
Presentation Type: Oral Paper:Papers for Topics
Location: Wasatch A/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 9:15 AM