Intercontinental biotic invasions: what can we learn from native populations and habitats?

The effectiveness of management strategies for invasive species is often hampered by a lack of clear understanding of the factors that limit species distributions. The distribution of exotic species, especially those that are invasive, are often so dynamic that limiting factors are difficult to identify. Comparisons of exotic species between their native ranges, where they are presumably close to equilibrium with controlling factors, and their ranges in areas of introduction can circumvent this difficulty. Such studies would help identify (1) limiting factors for distributions in native ranges, (2) factors associated with a high degree of invasiveness, (3) changes in genetics and morphology since introduction, which also might contribute to invasiveness, and (4) future directions and rates of invasion as a basis for developing detection/warning systems. Findings from such comparative studies would be highly valuable for understanding the dynamics of biological invasions and for improving the effectiveness of management to prevent or control invasives.