Carbon stocks in coffee agroforests and mixed dry tropical forests in the western highlands of Guatemala

Abstract

Tree removal in Latin American coffee agroforestry systems has been widespread due to complex and interacting factors that include fluctuat- ing international markets, government-supported agri- cultural policies, and climate change. Despite shade tree removal and land conversion risks, there is currently no widespread policy incentive encouraging the maintenance of shade trees for the benefit of carbon sequestration. In facilitation of such incentives, an understanding of the capacity of coffee agroforests to store carbon relative to tropical forests must be developed. Drawing on ecological inventories con- ducted in 2007 and 2010 in the Lake Atitlan region of Guatemala, this research examines the carbon pools of smallholder coffee agroforests (CAFs) as they com- pare to a mixed dry forest (MDF) system. Data from 61 plots, covering a total area of 2.24 ha, was used to assess the aboveground, coarse root, and soil carbon reservoirs of the two land-use systems. Results of this research demonstrate the total carbon stocks of CAFs to range from 74.0 to 259.0 Megagrams (Mg) C ha -1 with a mean of 127.6 ± 6.6 (SE) Mg C ha -1 . The average carbon stocks of CAFs was significantly lower than estimated for the MDF (198.7 ± 32.1 Mg C ha -1 ); however, individual tree and soil pools were not significantly different suggesting that agro- forest shade trees play an important role in facilitating carbon sequestration and soil conservation. This research demonstrates the need for conservation-based initiatives which recognize the carbon sequestration benefits of coffee agroforests alongside natural forest systems.