Biotic invasions can occur when organisms are trans ported to new, often distant, ranges where their descendants proliferate, spread , and persist. Biological invasions have been causing major environmental and ec ological damage, few areas remain sheltered from these immigrations in today's w orld, and they have become a priority concern for conservation biologists and la nd managers. In this paper, we discuss the process of invasions, the mechanism o f alien species displacing native species, and the pred...