Mature Andean forests as globally important carbon sinks and future carbon refuges

Abstract

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.

Plant Trait Assembly in Species-Rich Forests at Varying Elevations in the Northwest Andes of Colombia

“…Andean forests represent the greatest hotspot of diversity on Earth [1,2], as well as one of the regions most threatened by deforestation and climate change [3][4][5][6]. To assure effective forest conservation in this endangered ecosystem, an improved understanding of the mechanisms determining species assembly along elevational gradients is needed [7].…”

Changes in tree functional composition across topographic gradients and through time in a tropical montane forest

“…Given the tight relationship between plant traits and environmental variation [ 5 , 6 ], understanding trait-based responses to climate may provide valuable insights into the processes that will shape the composition and functioning of plant communities under changing environmental conditions [ 7 , 8 ]. Tropical montane ecosystems are critical repositories of biodiversity [ 9 , 10 ] and deliver many valuable ecosystem services [ 11 ]. Unfortunately, tropical montane systems are also believed to be especially sensitive to ongoing environmental alterations [ 12 ].…”

Root associated fungal lineages of a tropical montane forest show contrasting sensitivities to the long‐term addition of nitrogen and phosphorus

“…In tropical South America, large stretches of primary montane forests still occur along the humid eastern slopes of the Andes. Eastern Andean forests largely contribute to the declaration of the Andes as a biodiversity hotspot and are important carbon sinks (Duque et al, 2021; Myers et al, 2000; Spracklen & Righelato, 2014). Yet despite their remote location and ecological significance, these forests are facing multiple threats.…”