title: Synergistic impacts of habitat loss and fragmentation on model ecosystems.
abstract: Habitat loss and fragmentation are major threats to biodiversity, yet separating their effects is challenging. We use a multi-trophic, trait-based, and spatially explicit general ecosystem model to examine the independent and synergistic effects of these processes on ecosystem structure. We manipulated habitat by removing plant biomass in varying spatial extents, intensities, and configurations. We found that emergent synergistic interactions of loss and fragmentation are major determinants of ecosystem response, including population declines and trophic pyramid shifts. Furthermore, trait-mediated interactions, such as a disproportionate sensitivity of large-sized organisms to fragmentation, produce significant effects in shaping responses. We also show that top-down regulation mitigates the effects of land use on plant biomass loss, suggesting that models lacking these interactions-including most carbon stock models-may not adequately capture land-use change impacts. Our results have important implications for understanding ecosystem responses to environmental change, and assessing the impacts of habitat fragmentation.
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, UK l.bartlett@exeter.ac.uk.
authors.forename: Lewis J
authors.identifier: 0000-0002-4418-8071
authors.initials: LJ
authors.lastname: Bartlett
authors.affiliation: United Nations Environment Programme World Conservation Monitoring Centre, Cambridge, UK.
authors.forename: Tim
authors.identifier: 0000-0001-7361-0051
authors.initials: T
authors.lastname: Newbold
authors.affiliation: United Nations Environment Programme World Conservation Monitoring Centre, Cambridge, UK Computational Science Laboratory, Microsoft Research, Cambridge, UK.
authors.forename: Drew W
authors.initials: DW
authors.lastname: Purves
authors.affiliation: United Nations Environment Programme World Conservation Monitoring Centre, Cambridge, UK Computational Science Laboratory, Microsoft Research, Cambridge, UK Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Derek P
authors.initials: DP
authors.lastname: Tittensor
authors.affiliation: United Nations Environment Programme World Conservation Monitoring Centre, Cambridge, UK Computational Science Laboratory, Microsoft Research, Cambridge, UK.
authors.forename: Michael B J
authors.initials: MB
authors.lastname: Harfoot
mesh_terms: D044822:Biodiversity; D018533:Biomass; D002244:Carbon; D003247:Conservation of Natural Resources; D017753:Ecosystem; D010944:Plants
chemical_list: D002244:Carbon
keywords: biomass pyramid; ecosystem response; habitat fragmentation; habitat loss; land-use change; trophic shift