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United States Department of Agriculture

Agricultural Research Service

Title: Landscape moderation of biodiversity patterns and processes - eight hypotheses)

Author
item Tscharntke, Teja
item Tylianakis, Jason
item Rand, Tatyana
item Didham, Raphael
item Fahrig, Lenore
item Batary, Peter
item Bengtsson, Janne
item Clough, Yann
item Crist, Thomas
item Dormann, Carsten

Submitted to: Biological Reviews
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/14/2011
Publication Date: 8/1/2012
Publication URL: handle.nal.usda.gov/10113/54279
Citation: Tscharntke, T., Tylianakis, J.M., Rand, T.A., Didham, R.K., Fahrig, L., Batary, P., Bengtsson, J., Clough, Y., Crist, T.O., Dormann, C.F. 2012. Landscape moderation of biodiversity patterns and processes - eight hypotheses. Biological Reviews. 87(3): 661-685. DOI: 10.1111/j.1469-185X.2011.00216.x.

Interpretive Summary: Understanding how landscape characteristics (i.e. the pattern and composition of habitats in the landscapes surrounding a local habitat) affect local biodiversity patterns and ecological processes is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest the following seven hypotheses, which we hope will encourage a systematic research approach on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. (1) The dominance of beta diversity hypothesis: dissimilarity of local communities across the landscape determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. (2) The landscape species pool hypothesis: local biodiversity is influenced predominantly by the size of the landscape-wide pool of species. (3) The intermediate landscape-complexity hypothesis: effectiveness of local conservation management is highest in structurally simple, rather than in cleared (i.e. extremely simplified) or in complex landscapes (e.i. those with a high proportion of natural habitats). (4) The landscape-moderated insurance hypothesis: landscape complexity provides spatial and temporal insurance, i.e. rapid return of a system to its original state post disturbance, and stability of patterns and processes in changing environments. (5) The cross-habitat spillover hypothesis: spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes. (6) The landscape-moderated concentration and dilution hypothesis: spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations and the intensity of associated interactions (i.e. pollination and biological control). (7) The landscape-moderated trait and functional-group selection hypothesis: landscape structure drives the selection of particular species traits and functional groups, shaping the trajectory of community assembly. Shifting our research focus from local to landscape-moderated effects on biodiversity will be critical to developing solutions for future biodiversity and ecosystem service management.

Technical Abstract: Understanding how landscape characteristics affect local biodiversity patterns and ecological processes is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest the following seven hypotheses, which we hope will encourage a systematic research approach on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. (1) The dominance of beta diversity hypothesis: dissimilarity of local communities across the landscape determines the landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. (2) The landscape species pool hypothesis: local biodiversity is influenced predominantly by the size of the landscape-wide species pool. (3) The intermediate landscape-complexity hypothesis: effectiveness of local conservation management is highest in structurally simple, rather than in cleared (i.e. extremely simplified) or in complex landscapes. (4) The landscape-moderated insurance hypothesis: landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of patterns and processes in changing environments. (5) The cross-habitat spillover hypothesis: spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes. (6) The landscape-moderated concentration and dilution hypothesis: spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations and functional effects. (7) The landscape-moderated trait and functional-group selection hypothesis: landscape structure drives the selection of particular species traits and functional groups, shaping the trajectory of community assembly. Shifting our research focus from local to landscape-moderated effects on biodiversity will be critical to developing solutions for future biodiversity and ecosystem service management.

Last Modified: 8/24/2016
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