THE NICHE ECOSTATE-ECOROLE THEORY AND EXPANSION HYPOTHESIS
生态位态势理论与扩充假说

The niche ecostate-ecorole theory and niche expansion hypothesis were developed inthis paper. Each biological unit from individual to biosphere exits in a certain ecostate and hasits own ecorole in the environment. The "ecostate" of the biological unit is the accumiated re-sult of growth and development, learning, socio-economical development and the interactingwith surrounding environment in the past. The "ecorole" are the current effects on the envi-ronments, such as the rate of energy and matter exchange, productivity, growth rate, eco-nomic development rate and expanding rate for new space etc.. The varying curve of ecostateof biological unit is typicaly shaped as "S", the varying curve of ecorole of biological unit shapedlike a kind of "normal curve". The niche of a biological unit is the percentages of its ecostateand ecorole to the total ecostate and ecorole of all concerned units in a certain ecosystem, whichreflected its relative importance and the function status. The increase of the ecostate and eco-role caused by the growth potential in a biological unit is called "niche expansion". Niche ex-pansion is the momentum of the development and evoluation of the biosphere and the instinctcharacteristics of a leaving system. The rneasurement methods for ecostate and ecorole weretested in seven examples. The speclal properties of human niche expansion was also discussedhere.