Future land use and climate change escalate connectivity loss for Himalayan brown bears. (22nd August 2022)

• Record Type: Journal Article
• Authors: Dar, S. A.; Singh, S. K.; Wan, H. Y.; Cushman, S. A.; Bashir, T.; Sathyakumar, S.
• Is Part Of: Animal conservation. Volume 26:Number 2(2023)
• Page Start: 199
• Page End: 215
• Publication Date: 2022-08-22
• Subjects: biodiversity -- climate change mitigation -- fragmentation -- future projections -- habitat loss -- Himalayan brown bear -- multi‐scale -- range shift -- resistant kernels -- UNICOR; Conservation biology -- Periodicals; Wildlife conservation -- Periodicals; Conservation de la biodiversité; Conservation de la faune; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 333.95416
• DOI: 10.1111/acv.12813
• Languages: English
• ISSNs: 1367-9430

Abstract

Abstract: Climate and land use change are among the main drivers affecting virtually all species on earth. There were extensive studies projecting impacts of climate and land use changes on habitat loss and fragmentation but few on connectivity loss, and those that investigated connectivity did not disentangle the combined effects between climate change and land use change. This study uses the Himalayan brown bear ( Ursus arctos isabellinus) as a case study to illustrate an approach for disentangling the effects of climate change and human land use on population connectivity in the future. First, we assessed the current spatial pattern of population connectivity by simulating cumulative resistant kernels and factorial least‐cost paths with empirical field data. Then, we simulated the changes in connectivity due to future climate change under alternative emission scenarios (RCP 2.6 and RCP 8.5) in mid (2041–2060) and late (2061–2080) 21st century, which served as baseline scenarios of future connectivity. Finally, we estimated the changes in future connectivity due to human land use changes by adding a low and a high human land use activity scenario to the baseline climate change scenarios in our simulations. Alarmingly, all high emission scenarios, with or without human land use change, were projected to result in >99% reduction in current core areas of connectivity by the end of 21st century at 50th percentile threshold or above. This study demonstrates a spatially explicit scenario modeling approach to examine the interplay between future climate change and human land use on species connectivity. Our results suggest that regional land use regulations may be insufficient to conserve connectivity for HBB if nothing is done to reduce climate change at a global scale. Abstract : Climate change and land use change are threatening biodiversity and causing habitat and connectivity loss across the globe. We assessed the effects of climate change and land use change on population connectivity of Himalayan brown bears. Our models project that high emission scenarios, even excluding land use change, may lead to a near complete loss of high connectivity areas under a low dispersal threshold for the Himalayan brown bears by the end of 21 st century. On the other hand, low emission scenarios are projected to have large areas of high connectivity being preserved. Our findings suggest that conserving connectivity for the Himalayan brown bear will be a challenge because we have yet to see a major shift in future climate trajectory. This study supplements the literature that calls for climate change mitigation actions to conserve biodiversity.