Seed Longevity in Three Pairs of Native and Non-Native Congeners: Assessing Invasive Potential

The goal of this study was to determine whether seed longevity is an indicator of invasive potential. We studied annual (Polygonum) and woody perennial (Celastrus, Parthenocissus) non-native species and their native congeners in a three-year buried seed experiment. The woody perennial species formed a transient seed bank lasting only one year. In year one, both perennial non-native species had significantly greater germination than their native congeners. Both Polygonum species formed a persistent seed bank, but the invasive P. perfoliatum had greater longevity than the native P. sagittatum. The study demonstrated that seed bank strategies of invasive species are qualitatively similar to their less abundant native congeners, but there were significant quantitative differences.