Multipurpose habitat networks for short‐range and long‐range connectivity: a new method combining graph and circuit connectivity

Abstract

Summary Biodiversity conservation in landscapes undergoing climate and land‐use changes requires designing multipurpose habitat networks that connect the movements of organisms at multiple spatial scales. Short‐range connectivity within habitat networks provides organisms access to spatially distributed resources, reduces local extinctions and increases recolonization of habitat fragments. Long‐range connectivity across habitat networks facilitates annual migrations and climate‐driven range shifts. We present a method for identifying a multipurpose network of forest patches that promotes both short‐ and long‐range connectivity. Our method uses both graph‐theoretic analyses that quantify network connectedness and circuit‐based analyses that quantify network traversability as the basis for identifying spatial conservation priorities on the landscape. We illustrate our approach in the agroecosystem, bordered by the Laurentian and Appalachian mountain ranges, that surrounds the metropolis of Montreal, Canada. We established forest conservation priorities for the ovenbird, a Neotropical migrant, sensitive to habitat fragmentation that breeds in our study area. All connectivity analyses were based on the same empirically informed resistance surface for ovenbird, but habitat pixels that facilitated short‐ and long‐range connectivity requirements had low spatial correlation. The trade‐off between connectivity requirements in the final ranking of conservation priorities showed a pattern of diminishing returns such that beyond a threshold, additional conservation of long‐range connectivity had decreased effectiveness on the conservation of short‐range connectivity. Highest conservation priority was assigned to a series of stepping stone forest patches across the study area that promote traversability between the bordering mountain ranges and to a collection of small forest fragments scattered throughout the study area that provide connectivity within the agroecosystem. Landscape connectivity is important for the ecology and genetics of populations threatened by climate change and habitat fragmentation. Our method has been illustrated as a means to conserve two critical dimensions of connectivity for a single species, but it is designed to incorporate a variety of connectivity requirements for many species. Our approach can be tailored to local, regional and continental conservation initiatives to protect essential species movements that will allow biodiversity to persist in a changing climate.

Featured Collection Introduction: Connectivity of Streams and Wetlands to Downstream Waters

“…; Rayfield et al. ; Pilosof et al. ); empirical observations of spatial and temporal surface wetland‐stream hydrodynamics at field (Brooks et al.…”

Valuing Ecosystem Services and Disservices across Heterogeneous Green Spaces

“…The City of Chicago's stormwater management ordinance mandates multi-modal runoff prevention measures, including green insfrastructure (GI) products, practices and technologies [98] as part of an effort to protect Lake Michigan's drinking water supply. Parcel-scale GI as part of larger networks to connect urban green spaces can also provide an important opportunity to expand urban green spaces in a way that can provide habitat to slow species decline in urban areas [99]. Increased tree cover or GI on private lands can add to public investment in GI, further increasing connectivity of urban green spaces.…”

Applying network theory to prioritize multispecies habitat networks that are robust to climate and land‐use change

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