Abstract: Xiushan Island is located in the Zhoushan Fishery waters of East China Sea,which has a vast stretch of wetlands.The nearshore or around- shore parts of the wetlands,with peculiar island characteristics,are tightly associated with the living resources,especially fishery resources of Zhoushan Fishery waters.The peculiar ecological properties of the wetlands are characterized by particular island position.There is a high biodiversity of plants and animals in the wetlands,including over 300 species of plants and 108 species of birds (belonging to 26 families),such as oriental white stork (Ixobrychus minutus),known as the first class national protected animal,and swine hoe (Hydropotes inermis),known as the second class national protected animal.Xiushan wetlands comprise several tightly connected parts with different ecological functions,i.e.,subtidal zone wetland (shallow bay),intertidal zone wetland (mud,reed marshes),upper tidal zone (salty marsh,marsh),and degenerated wetland (salt field,culture pond,paddy field).As less attention was paid in the past,serious fragmentation took place in the wetland ecosystems.Recently,a natural protected area of the wetlands was constructed in Xiushan Island,and the wetland ecosystems have gained preliminary protection.

Key words: Black soil, Organic phosphorus, Mineralization process