Propagule Pressure - Case Studies

Case Studies

One particular study conducted by Robert I. Colautti et al. (2006), proposes that propagule pressure should act as a null model for studies that consider/compare processes of invasions to patterns of invasions. This study was a meta-analysis studying the characteristics of invasiveness and invasibility. The group researched the impact of thirteen invasiveness characteristics, and seven invasibility characteristics. Of the invasiveness characteristics studied, most did not significantly correlate to establishment, spread, abundance or impact of nonindigenous species. Propagule pressure, however, was shown to be a key contributor to both invasiveness and invasibility. This study found there was a positive association between establishment and propagule pressure. In regards to predicting invasions, it was found that propagule pressure was significantly associated with invasion successes and of the inclination of a habitat to be invaded. Of the thirteen other invasiveness characteristics studied, only three were significantly (positively or negatively) associated with invasiveness. Likewise, only two of the other six invasibility characteristics were shown to be significant. The communities that experienced more disturbances and resource availability achieved higher establishment and abundance of invaders.