Species extinction is a current global crisis. It is a great challenge to human beings to protect the nature and the biodiversity.Construction of nature reserves is one of the most important means to reduce the species extinction rate and to maintain the biological diversity.A reliable,comprehensive,and systematic theory has been urgently needed for the design and management of nature reserves. For such a theory to emerge,the theory of island biogcography by MacArthur and Wilson has been playing a catalytic...