Impact of climate warming on carbon metabolism and on morphology of invasive and native aquatic plant species varies between spring and summer

•A 3°C increase was applied on two invasive and two native species at two seasons.•The warming induced changes in morphological traits and in carbohydrate contents.•The growth of the invasive species was particularly stimulated by the warming in spring.•Carbohydrate patterns suggest common physiological mechanisms for the two invasives.•Climate warming may favour the colonisation by invasive species over native species.