Tuesday, August 3, 2010 - 4:00 PM

COS 36-8: Spatial patterns and availability of multiple ecosystem services-the effects of live fences in a tropical agricultural ecosystem

Kelly Garbach, University of California, Davis, Alejandra Martínez Salinas, Centro Agronómico Tropical de Investigación y Enseñanza, Fabrice De Clerck, Centro Agronómico Tropical de Investigación y Enseñanza, and Valerie T. Eviner, University of California Davis.

Background/Question/Methods

Conserving ecosystem services is a pressing concern given their critical role in supporting human well being and sustaining both habitat and biodiversity in natural and managed ecosystems. The Millennium Ecosystem Assessment has documented that land management to maximize provision of agricultural goods such as crops and livestock, has resulted in the degradation of other services (e.g. carbon sequestration, climate regulation). Consequently, there is a growing call to minimize tradeoffs and maximize synergies between services needed to provide agricultural goods and those needed to support and regulate ecological systems at broader scales. This study addresses a need for research in this area by determining how live fences, a common restoration planting of trees bordering cattle pastures, influence availability and spatial distribution of three ecosystem services: bird diversity; soil nutrients; and pasture productivity. The prevalence of live fences in central Costa Rica creates an ideal study system, with many established woody plantings replicated across the landscape. This study explored: 1) the extent to which live fences affect ecosystem services into surrounding pasture; and 2) how fence structural complexity influenced the spatial distribution of these three services. 
Results/Conclusions

We found that fence structural complexity (e.g. height, tree canopy radius) influenced the availability and distribution of all three ecosystem services, yet patterns varied independently for each. Live fences increased bird diversity, but this effect was limited to within the live fence planting. Bird diversity increased with increased structural complexity of the live fences.   Provisioning of soil nutrients was influenced across fields adjacent to live fences; C, N in surface soils (0-10cm) had a weak, positive correlation with fence structural complexity. Pasture productivity was reduced by live fences in the areas directly under the tree canopy (up to 5m into the pasture). This biomass suppression increased with had a strong negative correlation with fence complexity, and effects of reduced pasture biomass were noted up to 5m into the pasture, the area under the tree canopy of live fences. Measuring the availability and distribution of individual services both within plantings and surrounding areas is a promising approach to identify areas of overlap in enhanced provisioning of multiple ecosystem services, and quantitatively evaluate potential synergies and tradeoffs.