Long-distance dispersal: the key to plant invasiveness under climate change?

Current climate warming contributes to massive range shifts of plants and animals from lower to higher latitude. If plants shift their range faster than their enemies, the plants may eventually escape and become invasive in the new range (enemy release hypothesis). Invasion success can, therefore, depend on the dispersal capacity of the plant and its enemies. Taking a simulation modeling approach, we investigated the effect of the relative dispersal capacity of a plant and its belowground pathogen on the degree of range expansion and enemy release. We contrasted scenarios with and without climate change and included long-distance dispersal of plant and pathogen. In our scale-explicit model, population dynamics emerged from individual interactions in a field-scale grid of a few hectares and was extrapolated to a regional-scale grid covering a transeuropean temperature gradient. Plant range expansion increased with the dispersal capacity of the plant, but was independent of pathogen dispersal capacity. Climate change did not markedly affect range expansion, but had a positive effect on enemy release and the number of successful long-distance dispersal events. Interestingly, this ‘guerilla pattern’ vanished when plant dispersal capacity was lower than pathogen dispersal capacity. We conclude that long-distance dispersal can be the key to the invasive success of range expanding plants under climate change, but fast enemies can impede guerilla plants