Plant traits and population characteristics predict extinctions in a long-term survey of Mediterranean annual plants

Global and local environmental changes lead to frequent plant extinctions many of which occur in man-made habitats such as agricultural fields. Plant traits and site conditions modify risks of extinction, but strength and sense of their effect are not known yet. Here, we present a long-term survey of population sizes for Mediterranean annual plants that we revisited 20 years after their first record to evaluate climate, population size, traits and habitat requirements as drivers of local extinctions. Small populations had an increased probability of extinction in our data-set. Our analyses revealed that seed production and survival of seeds in the soil seed bank decreased extinction rate, whereas plant size increased extinction probability. Mean annual temperature increased extinction rates of annual plants in cereal fields. We discuss these effects as a response to recent and ongoing habitat changes, and discuss how traits may be used to guide conservation practices in the face of local extinctions.