Faculty of Mathematics and Natural Sciences - Biogeography

Faculty of Mathematics and Natural Sciences | Geography Department | Biogeography | News | Mapping extinction debt highlights conservation opportunities for birds and mammals in the South American Chaco

Mapping extinction debt highlights conservation opportunities for birds and mammals in the South American Chaco

 

Asunción Semper-Pascual | Leandro Macchi | Francesco Maria Sabatini | Julieta Decarre | Matthias Baumann | Pedro G. Blendinger | Bibiana Gómez-Valencia | Matías E. Mastrangelo | Tobias Kuemmerle

 

Habitat loss is the primary cause of local extinctions. Yet, there is considerable uncertainty regarding how fast species respond to habitat loss, and how time-delayed responses vary in space.

We focused on the Argentine Dry Chaco (c. 32 million ha), a global deforestation hotspot, and tested for time-delayed response of bird and mammal communities to landscape transformation. We quantified the magnitude of extinction debt by modelling contemporary species richness as a function of either contemporary or past (2000 and 1985) landscape patterns. We then used these models to map communities’ extinction debt.

We found strong evidence for an extinction debt: landscape structure from 2000 explained contemporary species richness of birds and mammals better than contemporary and 1985 landscapes. This suggests time-delayed responses between 10 and 25 years. Extinction debt was especially strong for forest specialists.

Projecting our models across the Chaco highlighted areas where future local extinctions due to unpaid extinction debt are likely. Areas recently converted to agriculture had highest extinction debt, regardless of the post-conversion land use. Few local extinctions were predicted in areas with remaining larger forest patches.

Synthesis and applications. The evidence for an unpaid extinction debt in the Argentine Dry Chaco provides a substantial window of opportunity for averting local biodiversity losses. However, this window may close rapidly if conservation activities such as habitat restoration are not implemented swiftly. Our extinction debt maps highlight areas where such conservation activities should be implemented.

 

Link to the manuscript: DOI: 10.1111/1365-2664.13074

 

Link to HU press release

 

Citation: Semper-Pascual A, Macchi L, Sabatini FM, et al. Mapping extinction debt highlights conservation opportunities for birds and mammals in the South American Chaco. J Appl Ecol. 2018;00:1–12. https://doi.org/10.1111/1365-2664.13074

 

GiantAnteater_JulietaDecarre-INTA.JPGCrownedSolitaryEagle_MartinLepez.jpg

Giant Anteater (Photo: Julieta Decarre - INTA)                                       Crowned Solitary Eagle (Photo: Martin Lepez)
 

ChacoanPeccary_JulietaDecarre-INTA.jpgBlack-bodiedWoodpecker_MartinLepez.JPG

Chacoan Peccary (Photo: Julieta Decarre - INTA)                                 Black-bodied Woodpecker (Photo: Martin Lepez)