Sustainability implications of carbon dynamics on the avocado frontier

Abstract

Carbon storage is examined along the avocado frontier in the state of Michoacán, Mexico, where native pine-oak forest is being rapidly lost for the sake of avocado production expansion. Carbon pools for aboveground biomass carbon and for belowground soil carbon were compared across avocado orchards and neighboring pine-oak forests. While aboveground carbon was found to be significantly higher in forests when compared to orchards, there was no significant difference found in soil carbon stocks between the two land uses. Mixed effects regression models were used to parse out the landscape scale heterogeneity that is affecting soil carbon beyond land cover alone. Temperature, precipitation, and fragmentation variables were all found to significantly impact soil carbon across the landscape studied. Furthermore, there is evidence of over-fertilization within orchards, particularly of phosphorus, which may be temporarily subsidizing soil carbon loss. Sustainability considerations, therefore, must consider land use decisions in relation to other soil nutrients, beyond just carbon, to comprehensively address sustainability concerns arising from the impacts of avocado production.