Experimental Evaluation Of Tradeoffs In Mosquito Production And Waterfowl Food Production In Moist Soil Habitats Of Californias Central Valley

Download or read book Experimental Evaluation of Tradeoffs in Mosquito Production and Waterfowl Food Production in Moist-soil Habitats of California's Central Valley written by Natalie Beatrice Washburn and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The extensive loss of California's historic wetlands heightens the importance of the remaining waterfowl habitats in the Central Valley. Previous research has demonstrated that irrigations during summer months increase moist-soil seed yield for waterfowl. However, this practice also increases production of mosquitoes. Mosquito production comes at a large cost to managers and these costs are influenced by irrigation frequency and duration. Due to increasing costs for wetland managers, there is a growing need to develop cost-effective management efforts to reduce mosquito production while still producing high quality habitat. For three years (2009-2011), we examined the effects of timing and duration of summer irrigations on aquatic invertebrate production (immature mosquitoes and their aquatic predators) using large-scale (1.5 acre) replicated plots at the Roosevelt Ranch in the Sacramento Valley. In addition, we examined the effects of these summer irrigations on moist-soil seed yield, plant structure and composition. We contrasted mosquito production values from these treatments with moist-soil seed yield. Total immature mosquito production differed among years and between irrigation treatments. Across all treatments, production in 2009 was significantly lower than in 2010 or 2011. Mosquito production during the first irrigation of the summer was always lower than during a second irrigation. Production of mosquitoes was highest in plots irrigated twice for 10 days (2x10) and lowest in the plots irrigated once for 4 days (1x4). Aquatic predators were more abundant in the plots with 10 and 20-day duration irrigations. Seed production, plant composition and vegetative structure also differed between treatment groups and years. Our results illustrated; 1) trade-offs exist between mosquito production and moist-soil seed production for waterfowl in California's Central Valley, 2) the greatest amount of moist-soil seed was produced in two irrigations of 10 days and the least was produced with no irrigation and 3) problem vegetation dominated units with no irrigation during the second and third years of our study.