Anais da Academia Brasileira de Ciências (Jun 2014)

Modeling the impact of net primary production dynamics on post-disturbance Amazon savannization

  • MÔNICA C.A. SENNA,
  • MARCOS H. COSTA,
  • ERIC A. DAVIDSON,
  • CARLOS A. NOBRE

DOI
https://doi.org/10.1590/0001-37652014108212
Journal volume & issue
Vol. 86, no. 2
pp. 621 – 632

Abstract

Read online

Amazon tropical forests are being replaced by pasturelands and croplands, but they sometimes revert to regrowth forest when abandoned after a period of agricultural use. Research suggests that this secondary regrowth is limited by climate and nutrient availability and, using a coupled biosphere-atmosphere model, we investigated patterns in the regrowth of the Amazon rainforest after a full deforestation event, considering different types of nutrient stress. We found that, over a 50 year regrowth period, the reduction of precipitation caused by large-scale deforestation was not sufficient to prevent secondary forest regrowth, but this decrease in precipitation combined with nutrient limitation, due to logging and frequent fires, did indeed prevent forest regrowth in central and southern Amazonia, leading to a savannization. These results are concerning, as the northern Mato Grosso region has the highest clearing rate in Amazonia. The low resilience of the forest under nutrient stress indicates that a large scale disturbance could greatly expand the area suitable for cropland, accelerating forest disappearance.

Keywords