HR: 16:00h
AN: NB14F-03 INVITED     [Abstracts]
TI: Long-term Temporal Variation in Biological Traits of Benthic Macroinvertebrates in California Mediterranean-Climate Streams
AU: * Beche, L A
EM: leah@nature.berkeley.edu
AF: University of California, Berkeley, Department of Environmental Science, Policy and Management 137 Mulford Hall, Berkeley, CA 94720 United States
AU: McElravy, E P
EM: mcelr@value.net
AF: University of California, Berkeley, Department of Environmental Science, Policy and Management 137 Mulford Hall, Berkeley, CA 94720 United States
AU: Resh, V H
EM: vresh@nature.berkeley.edu
AF: University of California, Berkeley, Department of Environmental Science, Policy and Management 137 Mulford Hall, Berkeley, CA 94720 United States
AB: The temporal variation of biological traits of benthic macroinvertebrates was analyzed using three long-term macroinvertebrate data sets (7, 8, and 20 years). We used 19 fuzzy-coded biological traits (e.g., maximum size, life cycle duration, and respiration mode) to describe temporal variation of biological traits and the relationships between trait composition and total annual precipitation, discharge, and near-bed hydraulics. Post wet-season (spring) samples were taken from 8 streams (1st-3rd order)in northern California, where the climate is mediterranean and precipitation shows high interannual variability. We used multivariate ordination to compare trait composition between years, and regression to determine the relationship of traits to rainfall, discharge, and sheer stress. Temporal variation in biological traits was significantly correlated with total annual rainfall and sheer stress, suggesting that both long-term and local, short-term patterns in environmental conditions influence trait composition. However, total annual rainfall best explained the interannual variation in individual traits (e.g., aerial respiration) and overall trait composition. For example, moderate body size (5-10 mm) and streamlined body shape were positively correlated with total rainfall, whereas aerial dispersal and diapause was negatively correlated with total rainfall.
DE: 9810 New fields (not classifiable under other headings)
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly