Modeling the effects of climate change on the distribution of Tagetes lucida Cav. (Asteraceae)

Abstract

Climate change threatens the future distributions of native, tropical species all around the world as increasing global temperature and, in several regions decreasing precipitation cause less suitable habitat to become available. Of particular interest in this paper is to construct a model of the potential impact of climate change on the distribution of the Pericón or Mexican Mint Marigold, Tagetes lucida, a native medicinal plant of important cultural and economic value in Mexico. We projected the future distribution of this species using the maximum entropy algorithm (MaxEnt) and five bioclimatic variables. Models were created using three global circulation models (CM3, CMIP5, HADGEM) in the years 2050 and 2070 and using two climate change scenarios (RCP 4.5 and RCP 8.5). The final model had an AUC = 0.92 and pROC = 1.645, indicating statistically significant results. These future distributions were compared to a current vegetation and land use map of Mexico. Our results predicted that under future climate change scenarios, less suitable habitat will become available, causing the range of Tagetes lucida to contract and shift northward. Current suitable habitat is threatened by agriculture, deforestation, and overgrazing, leading to habitat fragmentation and potentially creating a barrier to northern dispersal. Keywords: Pericón, Species distribution model, MaxEnt, Land use change