Four decades of Andean timberline migration and implications for biodiversity loss with climate change

PLoS One. 2013 Sep 11;8(9):e74496. doi: 10.1371/journal.pone.0074496. eCollection 2013.

Abstract

Rapid 21st-century climate change may lead to large population decreases and extinction in tropical montane cloud forest species in the Andes. While prior research has focused on species migrations per se, ecotones may respond to different environmental factors than species. Even if species can migrate in response to climate change, if ecotones do not they can function as hard barriers to species migrations, making ecotone migrations central to understanding species persistence under scenarios of climate change. We examined a 42-year span of aerial photographs and high resolution satellite imagery to calculate migration rates of timberline--the grassland-forest ecotone-inside and outside of protected areas in the high Peruvian Andes. We found that timberline in protected areas was more likely to migrate upward in elevation than in areas with frequent cattle grazing and fire. However, rates in both protected (0.24 m yr(-1)) and unprotected (0.05 m yr(-1)) areas are only 0.5-2.3% of the rates needed to stay in equilibrium with projected climate by 2100. These ecotone migration rates are 12.5 to 110 times slower than the observed species migration rates within the same forest, suggesting a barrier to migration for mid- and high-elevation species. We anticipate that the ecotone will be a hard barrier to migration under future climate change, leading to drastic population and biodiversity losses in the region unless intensive management steps are taken.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Altitude
  • Animal Migration*
  • Animals
  • Biodiversity
  • Cattle
  • Climate Change*
  • Conservation of Natural Resources*
  • Ecosystem
  • Forecasting
  • Herbivory
  • Peru
  • Plant Dispersal*
  • Trees*
  • Tropical Climate

Grants and funding

Funding for this research came from the Gordon and Betty Moore Foundation grant “Field Laboratory for Integrated Ecosystem Service Science in Upper Amazonian Peru” and National Science Foundation Division of Earth Sciences. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.