Climate change and biological invasion as additional threats to an imperiled palm

Abstract

Climate change and biological invasion are major threats to biodiversity, but their combined effects have rarely been quantified. The introduction of congeneric non-native species, in particular, can be especially problematic for native species due to competition and hybridization. Here, we quantify the impacts of climate change on the distribution of an ecologically and economically important native species, Euterpe edulis, and on the invasion potential of its congeneric E. oleracea, across the Atlantic Forest biodiversity hotspot. We modelled current and future environmental suitability for both species, using a comprehensive set of algorithms and climatic scenarios, and quantified the extent of overlap of their environmentally suitable areas. Climate change reduced environmental suitability for E. edulis, but had neutral effects on E. oleracea. Current and future overlap areas, where competition and hybridization are more likely, were concentrated mostly in the southeastern region of Brazil. Our results suggest that native and non-native congeneric species respond differently to climate change, and that climate change and the introduction of E. oleracea are additional threats to the threatened E. edulis. We recommend avoiding new introductions of E. oleracea especially in the southeastern portion of the Atlantic Forest, and the maintenance of protected areas especially in the southern region.