To improve our understanding in invasion ecology and efficiency in invasion management, two fundamental questions need be addressed: 1) what are the spatiotemporal patterns of invasion and 2) what knowledge has been gained to understand the invasion patterns and processes? Here, we used garlic mustard (Alliaria petiolata) as a model species to illustrate how to address these questions for non-intentionally introduced and cultivated invaders. Using 150 years’ worth of historical data, we re-constructed and measured the spatiotemporal patterns of garlic mustard invasion across the eastern U.S. We also analyzed all 225 research articles published between 1975 and 2015 to understand the research that has been conducted on this model species and the development of invasion ecology in general.
Results/Conclusions
As a species that is not intentionally introduced and cultivated, garlic mustard has a long establishment period (~60 years) after its initial introduction, followed by a still on-going long expansion stage (~9 counties per year). Its spatial dispersion follows a short-distance diffusion model, i.e., distribution growing outward from a single foci introduction point. The dispersion is dominated by relatively short-distance dispersals, but with high affinity to transportation networks. Unfortunately, research on this model species did not catch up until over a century after its initial introduction. Most of the early research focused on the characteristics about the species such as seed production and growth, whereas recent and current research focuses on the species’ impacts on soil and community, and the strategies for management and control. Other research, such as landscape- to regional-scale impacts and dynamics, which are important for effective invasion prevention and mitigation, is still limited.