It is largely unknown how South America’s Andean forests affect the global carbon cycle, and thus regulate climate change. Here, we measure aboveground carbon dynamics over the past two decades in 119 monitoring plots spanning a range of >3000 m elevation across the subtropical and tropical Andes. Our results show that Andean forests act as strong sinks for aboveground carbon (0.67 ± 0.08 Mg C ha−1 y−1) and have a high potential to serve as future carbon refuges. Aboveground carbon dynamics of Andean forests are driven by abiotic and biotic factors, such as climate and size-dependent mortality of trees. The increasing aboveground carbon stocks offset the estimated C emissions due to deforestation between 2003 and 2014, resulting in a net total uptake of 0.027 Pg C y−1. Reducing deforestation will increase Andean aboveground carbon stocks, facilitate upward species migrations, and allow for recovery of biomass losses due to climate change.
Bibliographical noteFunding Information:
A.D. received funding from the Dirección de Investigaciones de la Universidad Nacional de Colombia Sede Medellín (DIME). F.C. was funded by the Swiss Agency for Development and Cooperation (SDC), Grant/Award Number: PA0042-C011-0031 and by Universidad de las Américas Research Grant: FGE.FCC.19.15. S.G.C. was funded by COLCIENCIAS (Convocatoria 767). The Madidi Project has been supported by grants from the National Science Foundation (DEB-0101775, DEB-0743457 and DEB-1836353), the National Geographic Society (NGS 7754-04 and NGS 8047-06), The Living Earth Collaborative and various other organizations and individuals. K.J.F. was funded by an award by the US National Science Foundation (DEB LTREB 1754664). O.L.P. was supported by an ERC Advanced Grant 291585 (“T-FORCES”). P.K. was funded by the US National Science Foundation (DEB 1753621) and an Institute of International Education Fulbright Fellowship. We acknowledge the support provided by the Swiss Cooperation through the Programa Bosques Andinos conducted by CONDESAN who supported the workshop where the idea of this study was conceived as part of the core activities promoted by the Red de Bosques Andinos (RBA).
© 2021, The Author(s).