Ecosystem services such as natural pest control and pollination can contribute towards agricultural production whilst simultaneously reducing its environmental harm. While agri-environmental schemes (AES) can increase landscape heterogeneity and promote biodiversity conservation, there is little research on how they affect ecosystem service provision. This was explored by incorporating a mechanistic understanding of the effects of biodiversity on ecosystem services, focusing on farm-scale spill-over effects from AES to crop habitats, species interactions and functional traits. AES promoted spill-over of functionally diverse carabid beetle natural enemies to nearby fields. No concurrent change in species richness or abundance was detected, highlighting functional traits as an important monitoring focus. Body mass was demonstrated as a key trait in laboratory experiments investigating the functional response of carabid beetle interactions with prey. Attack rates increased and prey handling times decreased with increasing predator-prey body-mass ratio. Emergent effects of predator interspecific interactions on prey consumption were also driven by differences in body mass between predator species. Using multi-trophic thistle flower head communities as a study system, AES were found to alter the interaction between a speCialised herbivore and its plant host, but there was no evidence that this was driven by cascading effects from parasitoids. The effect of AES floral margins on pollinator visitation and pollination of target flowering plants in adjacent habitats showed variable effects. ·Target plants surrounded by a greater proportion of floral margins suffered decreased species richness of hoverfly visitors potentially through competitive effects, but no effect on bee visitation or on the outcome for pollination service was detected. Overall the results suggest ecosystem services are often underpinned by complex combinations of species traits, which determine species responses to biotic and abiotic factors. Further exploration of links between trait-driven responses and ecosystem service provision may provide a useful basis for understanding and promoting sustainable agriculture.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:658034 |
| Date | January 2014 |
| Creators | Ball, Sara L. |
| Publisher | University of Reading |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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