Multiscale consensus habitat modeling for landscape level conservation prioritization

Erin E Poor,Jennifer M Mullinax,Brian K Scheick

doi:10.1038/s41598-020-74716-3

Abstract

Globally, wide-ranging carnivore populations are imperiled due to human-caused habitat fragmentation. Where populations are fragmented, habitat quantification is often the first step in conservation. Presence-only species distribution models can provide robust results when proper scales and data are considered. We aimed to identify habitat for a fragmented carnivore population at two scales and aid conservation prioritization by identifying potential future habitat fragmentation. We used location data and environmental variables to develop a consensus model using Maxent and Mahalanobis distance to identify black bear (Ursus americanus floridanus) habitat across Florida, USA. We compared areas of habitat to areas of predicted sea level rise, development, and protected areas. Local-scale models performed better than state-scale models. We identified 23,798 km2 of habitat at the local-scale and 45,703 km2 at the state-scale. Approximately 10% of state- and 14% of local-scale habitat may be inundated by 2100, 16% of state- and 7% of local-scale habitat may be developed, and 54% of state- and 15% of local-scale habitat is unprotected. Results suggest habitat is at risk of fragmentation. Lack of focused conservation and connectivity among bear subpopulations could further fragmentation, and ultimately threaten population stability as seen in other fragmented carnivore populations globally.

Highlights

IntroductionStand-alone presence-only models have come under some scrutiny due to their sensitivity to inputs, scale, and accuracy measures[28,29,30]
While sprawl in the U.S seems to be beginning to decrease[120], that is not the case in Florida, where the human population is growing and wildlife habitat is increasingly fragmented due to anthropogenic impacts and/or climate change. We provide these results to guide landscape conservation for Florida black bears, and this research underscores the point that while species may recover in population size and distribution, conservation efforts should not wane in the face of projected human population growth and development
In Florida, we suggest that managers focus generally on wetland areas at higher elevation, in unprotected areas in the South Central and Central bear management unit (BMU)

Summary

Introduction

Stand-alone presence-only models have come under some scrutiny due to their sensitivity to inputs, scale, and accuracy measures[28,29,30] These models can provide robust information about habitat distribution, especially when multiple models are used to identify a habitat ‘consensus’ and limit the uncertainty due to one specific model type[31,32]. As a major step in the statewide black bear habitat conservation effort, we aim to identify and quantify Florida black bear habitat (1) at the landscape scale across all of Florida, and (2) at the local, subpopulation scale, using the BMU extent, by applying consensus presence-only SDMs. For conservation prioritization, we identify areas of suitable habitat that will be threatened by projected sea level rise or by projected future development and areas that are currently protected

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Discussion

Conclusion