摘要:Anthropogenic global change is radically altering climate, mineral cycles, land cover, and biotic communities (Turner et al. 1993, Vitousek 1994). These changes ensure that everywhere on Earth is affected by human actions. In some areas, such as the center of large cities, human transformation is near absolute, whereas in other places, such as remote parks, human influence is felt chiefly through the alteration of global cycles. However, no place is free from multiple, confounded human impacts. Consequently, ecological studies, whether they attend to or not, are partially studying the impact of anthropogenic change.