Temporal dynamics of range-expander and congeneric native plant responses during and after extreme drought events

Current climate change causes range shifts of many species to higher latitudes and altitudes, and enhances their exposure to extreme weather events. It has been shown that range shifting plant species may perform differently in the new soil than related natives, however, little is known about how extreme weather events influence range-shifting plants compared to related natives. Here, we used outdoor mesocosms to study how range-shifting plant species respond to extreme drought in live soil from a habitat in the new range with and without live soil from a habitat in the original range. During summer drought, shoot biomass of the range-expanders was reduced. In spite of this, in the mixed community range-expanders produced more shoot biomass than congeneric natives. In mesocosms with a history of range-expanders in the previous year, native plants produced less biomass. Plant legacy or soil origin effects did not change the response of natives or range-expanders to summer drought. During...