Invasive Plants and Their Response to Energy Development

Abstract

Increases in human developments, travel, and trade greatly facilitate the movement of organisms to locations where they do not naturally occur (Mack and Lonsdale 2001). These organisms are called nonnative species, andexotic, alien, introduced, andnonindigenousare common synonyms for this term. Once a nonnative species is introduced to a new area, it may no longer be susceptible to the population controls that coevolved with it in its native habitat. In some cases, nonnative species may have a benign relationship with native species, resulting in little effect on ecosystem processes. In other cases, the nonnative species may have a competitive advantage over native species and spread quickly, becoming invasive. Excluding cultivars, 10–20 percent of the estimated 50,000 nonnative species introduced to the United States (Pimentel et al.2005) will become invasive (Chornesky and Randall 2003). Invasive species affect native species by direct competition and by indirectly altering ecosystem processes such as food webs, hydrology, nutrient and decomposition cycles, and natural disturbance regimes (Vitousek et al.1997a, 1997b; Mack et al.2000; Mooney et al. 2005). Most invasions detrimentally affect the environment, human health, or the economy, and in some cases native species are extirpated or become extinct.