Demonstrating a conceptual model for multispecies landscape pattern indices in landscape conservation

Nathan M Tarr

doi:10.1007/s10980-019-00888-7

Abstract

ContextOur ability to understand the implications of prescriptions for landscape change (i.e., conservation actions) is constrained by the scopes of spatial pattern indices employed to describe landscapes. Most indices are suited for use with a single species or habitat, but the consequences of conservation actions are inherently multispecies. Hence, indices that incorporate information for multiple species are desirable.ObjectivesI describe a conceptual model for multispecies spatial pattern indices that incorporates species-specific habitat definitions and scales of landscape effects. I explore its utility for conservation planning and present insights and suggestions for its application.MethodsThe conceptual model employs habitat maps and estimates of species’ scales of effect for habitat amount within landscapes surrounding sites. I present three indices rooted in the model: cumulative habitat amount, fragmented species count (FSC), and fragmented species-habitat count (FSHC). Comparisons of FSC and FSHC values at individual sites can reveal areas of high importance for protection as well as a measure of conservation design problem complexity. I demonstrate application of the indices for 40 species within a study area in the northwestern U.S.ResultsThe indices provided a visualization of spatial patterns in multispecies habitat fragmentation across the study region, revealing areas with relatively high levels of habitat fragmentation and sites where habitat configuration is of high importance for the species analyzed.ConclusionsThe conceptual model provides descriptions of landscapes that can provide important context for conservation actions. Implementation may warrant further development, exploration of sensitivities, or case-specific refinements.

Highlights

Habitat fragmentation has been considered a primary threat to biodiversity because of widespread anthropogenic land use change and what are believed by many to be negative relationships between the spatial patterns of fragmented landscapes and species that inhabit them (Fardila et al 2017)
On the basis of those relationships, some conservationists have assessed the implications of historical landscape changes on biodiversity and prescribed changes that would alter the spatial configuration of habitat to increase connectivity and mitigate fragmentation effects (Fardila et al 2017)
Efforts to understand the ecological implications of landscape changes have largely focused on single species or, alternately, on animal assemblages that are associated with a single natural land cover type (Lindenmayer and Fischer 2006; Fardila et al 2017)