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

SEMPER-PASCUAL, ASUNCIÓN; MACCHI, LEANDRO; SABATINI, FRANCESCO MARIA; DECARRE, JULIETA; BAUMANN, MATTHIAS; BLENDINGER, PEDRO G.; GÓMEZ-VALENCIA, BIBIANA; MASTRANGELO, MATÍAS E.; KUEMMERLE, TOBIAS

JOURNAL OF APPLIED ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2017

0021-8901

1. 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-delayedresponses vary in space.2. We focused on the Argentine Dry Chaco (c. 32 million ha), a global deforestationhotspot, and tested for time-delayed response of bird and mammal communities tolandscape 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.3. We found strong evidence for an extinction debt: landscape structure from 2000explained contemporary species richness of birds and mammals better than contemporary and 1985 landscapes. This suggests time-delayed responses between10 and 25 years. Extinction debt was especially strong for forest specialists.4. 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.5. Synthesis and applications. The evidence for an unpaid extinction debt in theArgentine Dry Chaco provides a substantial window of opportunity for averting localbiodiversity losses. However, this window may close rapidly if conservation activities such as habitat restoration are not implemented swiftly. Our extinction debtmaps highlight areas where such conservation activities should be implemented.