COS 50-7 - Farm-scale and landscape factors influence mobile species conservation in agricultural landscapes

Wednesday, August 10, 2016: 3:40 PM
304, Ft Lauderdale Convention Center
Elissa M. Olimpi, Environmental Studies, University of California, Santa Cruz, Santa Cruz, CA
Background/Question/Methods

Managing for biodiversity in working landscapes requires that we consider the trade-offs and synergies between production and conservation. In agricultural landscapes, multi-scalar drivers of biodiversity loss extend from the farm- to landscape scale, yet it is often unclear how to best manage species that provide valuable ecosystem services. Landscape-level agricultural intensification decreases matrix quality and permeability; farm-scale agricultural intensification can also reduce matrix connectivity via removal of treelines, hedgerows, and riparian habitat that serve as important corridors. Mobile species in higher trophic levels generally respond to factors at larger scales; however, for insectivorous bats, the availability of insect prey also drives patterns in foraging, and insects respond to local management practices. We assessed the local and landscape effects of agricultural intensification on bats using passive acoustic monitoring data from 54 sites in the Central Coast Region, CA on paired farms (low and high intensification) and in nearby natural habitat spanning a range of farming practices and landscape contexts. We hypothesized that factors at both the local- and landscape- scale would impact bat communities, with stronger responses to landscape-scale factors.

Results/Conclusions

We found that both farm-scale and landscape-scale factors impact bat communities. Diversified farming practices, including higher weed and crop diversity and hedgerows, were associated with greater relative bat abundance, as well as fewer pest insects and more beneficial insects. At the landscape scale, the amount of surrounding semi-natural habitat was positively correlated with greater bat species richness and activity. Interestingly, natural habitat fragments have a greater positive impact on bats in landscapes dominated by agriculture. These findings inform management for synergistic outcomes for conservation and agricultural production that are essential for managing biodiversity in working landscapes. Application of our findings could decrease the negative effects of agriculture and prevent regional declines in bat biodiversity, as well as enhance benefits to farmers in the form of free, natural pest suppression.