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Faculty of Mathematics and Natural Sciences - Biogeography

Faculty of Mathematics and Natural Sciences | Geography Department | Biogeography | News | Habitat amount or habitat fragmentation: what drives time-delayed responses of biodiversity to land-use change?

Habitat amount or habitat fragmentation: what drives time-delayed responses of biodiversity to land-use change?


A. Semper-Pascual, C. Burton, M. Baumann, J. Decarre, G. Gavier-Pizarro, B. Gómez-Valencia, L. Macchi, M. E. Mastrangelo, F. Pötzschner, P. V. Zelaya and T. Kuemmerle

 

Summary:

Land-use change is the most important driver of species’ extinctions, but how fast do species respond to landscape change, and how important is habitat loss versus fragmentation? We showed that birds and mammals in the Argentine Dry Chaco go locally extinct where habitat loss dominates, however, they can persist in fragmented landscapes. These findings contribute to better understand the effect of habitat fragmentation and the drivers of extinction debt – and the window of time we have to avert future extinctions.

Abstract:

Land-use change is a root cause of the extinction crisis, but links between habitat change and biodiversity loss are not fully understood. While there is evidence that habitat loss is an important extinction driver, the relevance of habitat fragmentation remains debated. Moreover, while time delays of biodiversity responses to habitat transformation are well-documented, time-delayed effects have been ignored in the habitat loss versus fragmentation debate. Here, using a hierarchical Bayesian multi-species occupancy framework, we systematically tested for time-delayed responses of bird and mammal communities to habitat loss and to habitat fragmentation. We focused on the Argentine Chaco, where deforestation has been widespread recently. We used an extensive field dataset on birds and mammals, along with a time series of annual woodland maps from 1985 to 2016 covering recent and historical habitat transformations. Contemporary habitat amount explained bird and mammal occupancy better than past habitat amount. However, occupancy was affected more by the past rather than recent fragmentation, indicating a time-delayed response to fragmentation. Considering past landscape patterns is therefore crucial for understanding current biodiversity patterns. Not accounting for land-use history ignores the possibility of extinction debt and can thus obscure impacts of fragmentation, potentially explaining contrasting findings of habitat loss versus fragmentation studies.

Link to the manuscript: https://doi.org/10.1098/rspb.2020.2466

Citation:  Semper-Pascual, A., C. Burton, M. Baumann, J. Decarre, G. Gavier-Pizarro, B. Gómez-Valencia, L. Macchi, M. E. Mastrangelo, F. Pötzschner, P. V. Zelaya, and T. Kuemmerle. 2021. How do habitat amount and habitat fragmentation drive time-delayed responses of biodiversity to land-use change? Proceedings of the Royal Society B: Biological Sciences 288:20202466.

 

 

Fig.: Asunción Semper-Pascual