ABSTRACT
Charles Elton, a pioneer in population ecology, wrote of how ecological explosions were threatening the world (Elton 1958). Nearly half a century later, his early warning has become one of the most important environmental crises of our time. Biological invasions have caused more species extinctions than did human-induced climate change (D’Antonio and Vitousek 1992), and are the second leading cause of species extinctions after habitat loss. Biological invasion is one of the major reasons of biodiversity depletion. Invasive plants, in particular, are to blame for much of native species decline and ecosystem degradation (Wilcove et al. 1998). The invasion of native ecosystems by alien plants can lead to alterations in nutrient cycling, fire regime, hydrology, energy budgets, and native species abundance and survival (Mack et al. 2000).
