ABSTRACT
As a center of production and consumption, urban ecosystems have satisfied human demands throughout most of history. Until recently, the stress of resource depletion and emission of pollutants has remained within the ecosystem's regenerative capacity, and the urban ecosystem was able to self-restore. However, with rapid urbanization, more and more intensive human activities have led to adverse environmental changes that impair societal services and jeopardize sustainability [1]. People have begun to worry about whether the urban ecosystem can support dense populations and provide sustainable services. Therefore, urban ecosystem health has
become a scientific topic and a goal of urban development, which integrates the means by which human demands are satisfied with the ecosystem's ability for renewal [2,3].
