Rapid assessment of insect pollination services to inform decision-making

Pollinator declines have prompted efforts to assess how land-use change affects insect pollinators and pollination services in agricultural landscapes. Yet many tools to measure insect pollination services require substantial landscape-scale data and technical expertise. In expert workshops, 3 straightforward methods (desk-based method, field survey, and empirical manipulation with exclusion experiments) for rapid insect pollination assessment at site scale were developed to provide an adaptable framework that is accessible to nonspecialist with limited resources. These methods were designed for TESSA (Toolkit for Ecosystem Service Site-Based Assessment) and allow comparative assessment of pollination services at a site of conservation interest and in its most plausible alternative state (e.g., converted to agricultural land). We applied the methods at a nature reserve in the United Kingdom to estimate the value of insect pollination services provided by the reserve. The economic value of pollination services provided by the reserve ranged from US$6163 to US$11,546/year. The conversion of the reserve to arable land would provide no insect pollination services and a net annual benefit from insect-pollinated crop production of approximately $1542/year (US$24∙ha^–1∙year^–1). The methods had wide applicability and were readily adapted to different insect-pollinated crops: rape (Brassica napus) and beans (Vicia faba) crops. All methods were rapidly employed under a low budget. The relatively less robust methods that required fewer resources yielded higher estimates of annual insect pollination benefit.     

Effect of Introduced Mosquitofish on Pacific Treefrogs and the Role of Alternative Prey

Abstract: Mosquitofish ( Gambusia affinis ) are distributed by many mosquito control programs because of their broad habitat tolerance and because they are considered by some to be effective mosquito predators. As a result, mosquitofish have become established as an exotic species in numerous perennial streams in the Santa Monica Mountains within the last 10–15 years. Previous studies have found that mosquitofish prey heavily on California newt (   Taricha torosa ) larvae that inhabit mountain streams. We found Pacific treefrog (   Hyla regilla ) tadpoles in the stomachs of 65% of stream-caught mosquitofish. In both laboratory and field experiments, we found that mosquitofish preyed heavily on treefrog tadpoles, even when high densities of mosquito larvae were presented as alternative prey. Thus, despite apparent high densities of Pacific treefrog populations, our experiments suggest that introduced mosquitofish may negatively affect stream-breeding H. regilla in the Santa Monica Mountains.