HR: 11:30h
AN: NB22B-05    [Abstracts]
TI: Aquatic Insect Emergence in Post-Harvest Flooded Agricultural Fields in the Southern San Joaquin Valley, California
AU: * Moss, R C
EM: skip0279@csufresno.edu
AF: California State University, Fresno, Biology Department M/S SB73 California State University, Fresno, Fresno, CA 93740 United States
AU: Blumenshine, S
EM: sblumens@csufresno.edu
AF: California State University, Fresno, Biology Department M/S SB73 California State University, Fresno, Fresno, CA 93740 United States
AU: Fleskes, J
EM: joe_fleskes@usgs.gov
AF: United States Geological Survey, USGS-Western Ecological Research Center 6924 Tremont Road, Dixon, CA 95620 United States
AB: California's Southern San Joaquin Valley is one of the most important waterbird areas in North America, but has suffered a disproportionate loss of wetlands when compared to other California regions. This project analyzes the habitat value of post-harvest flooded cropland by measuring the emergence of aquatic insects across multiple crop types. Aquatic insect emergence was sampled from post-harvest flooded fields of four crop types (alfalfa, corn, tomato, wheat), August-October, 2003-2004. Emergence was measured using traps deployed with a stratified random distribution to sample between and within field variation. Emergence rate and emergent biomass was significantly higher in flooded tomato fields. Results from corn fields indicate that flooding depth was correlated (r=0.095) with both diel temperature fluctuation and emergence rate. Chironomus dilutus larvae were grown in environmental chambers, under two thermal treatments with the same mean but different amplitudes (high: 15°-32°C, low: 20°-26°C) to investigate thermal fluctuation effects on survival and biomass. Larval survival (4x) and biomass (2x) were significantly greater in the low versus high temperature fluctuation treatment. This research has the potential to affect agricultural management throughout the 12,600 km² region, increase aquatic insect production and aid in the recovery of declining bird populations.
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly