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Environmental change and the carbon balance of A mazonian forests
Author(s) -
Aragão Luiz E. O. C.,
Poulter Benjamin,
Barlow Jos B.,
Anderson Liana O.,
Malhi Yadvinder,
Saatchi Sassan,
Phillips Oliver L.,
Gloor Emanuel
Publication year - 2014
Publication title -
biological reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.993
H-Index - 165
eISSN - 1469-185X
pISSN - 1464-7931
DOI - 10.1111/brv.12088
Subject(s) - amazon rainforest , biome , climate change , deforestation (computer science) , environmental science , amazonian , primary production , land use, land use change and forestry , carbon sink , global warming , carbon cycle , greenhouse gas , agroforestry , land use , environmental protection , geography , ecology , ecosystem , biology , computer science , programming language
Extreme climatic events and land‐use change are known to influence strongly the current carbon cycle of A mazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the B razilian A mazon and to understand how they interact with each other. By analysing the outputs of the I ntergovernmental P anel for C limate C hange ( IPCC ) Assessment R eport 4 ( AR4 ) model ensemble, we demonstrate that A mazonian temperatures and water stress are both likely to increase over the 21st C entury. Curbing deforestation in the B razilian A mazon by 62% in 2010 relative to the 1990s mean decreased the B razilian A mazon's deforestation contribution to global land use carbon emissions from 17% in the 1990s and early 2000s to 9% by 2010. Carbon sources in A mazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP ) of +0.16 (ranging from +0.11 to +0.21) Pg C year −1 in the B razilian A mazon, equivalent to 13.3% of global carbon emissions from land‐use change for 2008, can be negated or reversed during drought years [ NBP = −0.06 (−0.31 to +0.01) Pg C year −1 ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the A mazonian gross forest sink to offset approximately 42% of global land‐use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the A mazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency.