Abstract: Fujian is a mountainous province with less farmland and abundant labor in southeast coastal regions of China. Resources of temperature, solai radiation and rainfall in paddy field ecosystems are different with the change of latitude and altitude. Analysis results show that there are four kinds of discontinuous climatic layers and four types of paddy soils. According to the properties of stratosphere, the types of paddy soils and rice cropping systems, ten ecotopes are classified. The photo-utilization efficiency,output/input tatio of subsidiary energy and natural fertility of paddy soils are also investigated and discribed in detail. At the same time, ways for further increasing the productivity of the ecosystem are discussed.

Key words: Nonpoint pollution, Ecological engineering, Control, Technology