Mapping the extinction debt in the Chaco

Although my heart beats for temperate forests, collaborating with Asunción Semper-Pascual took me for once (alas, only figuratively) to the tropical dry forests of the Argentinian Chaco, to do research on a very important questions:

Given the high rate of deforestation currently observed in the Chaco, what proportion of the mammal and bird diversity we currently observe in the landscape is deemed to go extinct in the near-future? In other words, is there an Extinction debt? And can we map it to highlight areas where a high extinction rate is expected, so to priotize areas in urgent need of restoration?

In the paper just published on the Journal of Applied Ecology, we showed we can.

The Gran Chaco region, is South America’s largest tropical dry forest, and stretches across Argentina, Paraguay, Bolivia and Brazil. Although being considered a biodiversity hotspot, harbouring more than 400 birds, 150 mammals, 120 reptiles and 100 amphibian species, the Gran Chaco region suffers from a high anthropogenic pressure: since the 1990s, and especially after 2000, the region experienced one of the highest deforestation rates world-wide, mainly due to the expansion of soybean production and industrial cattle ranching. Given the high biodiversity, the high anthropogenic pressure and the limited extent of protected areas, the Chaco is in urgent need of conservation action.

In this dramatic context, we found that a substantial window of opportunity exists for averting local biodiversity losses. After a stretch of land is deforested, it takes 10-25 before having species go locally extinct. This means that if we act now, strengthening conservation and implementing restoration we could avert biodiversity loss. This window may close rapidly, though, if we do not act swiftly!

I recommend those interested to check out the paper:

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;00:112.


Here the Press Release from Humboldt-Universität zu Berlin