Abstract
Recent progress in studying mechanisms of biological invasion is reviewed involving several aspects, such as biological characteristics of exotic species, interaction among exotic species and their new neighbours, the relationships between species diversity and community resistance to invasion, the effects of changing ecological factors in new habitats. We also analyze the progress of research methodologies and some unsolved vague points in this field. According to recent studies, the mechanisms of biological invasion seem so diverse that no common pattern could explain all cases. A better understanding of invasive mechanisms is essential in developing ecological theory and significant in controlling exotic pests.