The ability of invasive plants to rapidly adapt to local climates -- and potentially to climate change -- may be a key factor in how quickly they spread.
According to new research published in Science by UBC evolutionary ecologist Rob Colautti, it is rapid evolution -- as much as resistance to local pests -- that has helped purple loosestrife to invade, and thrive in, northern Ontario.
"The ability of invasive species to rapidly adapt to local climate has not generally been considered to be an important factor affecting spread," says Colautti, an NSERC Banting Postdoctoral Fellow with the UBC department of Botany who started the research in 2007 as a PhD student at the University of Toronto.
Photo editors: Photos of the purple loosestrife, and credits, available at: https://drive.google.com/folderview?id=0B4jOHnSl9Z_wTEhady1lYlIwOTA&usp=sharing
"Instead, factors such as escape from natural enemies including herbivores, predators, pathogens or parasites were thought to explain how species become invasive," says Colautti. "We found that the evolution of local adaptation to climate in purple loosestrife increased reproduction as much as or more than escaping natural enemies. Understanding that species can evolve rapidly to local climates is important for predicting how invasive species spread and how native and non-native species alike will respond to climate change."
To determine whether populations have evolved local adaptation, Colautti and University of Toronto professor Spencer Barrett collected seeds from three different climatic regions and grew them at three sites spanning the distribution of the species in eastern North America. They found that 'home' plants collected from latitudes most similar to each common garden location always had higher fitness than the 'away' plants. For example, plants
|Contact: Rob Colautti|
University of British Columbia