Abstract: Ecological rehabilitation was previously emphasized on the restoration of natural ecosystem, with the stress on the recovery of damaged ecosystem to primary ecosystem via various techniques and means, but nowadays, it tegrates the restoration of natural ecosystem and the construction of artificial ecosystem. The conjugated ecological rehabilitation based on complex ecosystem theory is to rehabilitate the damaged ecosystem structure, function and process, and to construct and maintain the ecosystem to provide human with ecosystem services. Taking the Mentougou District in Beijing as an example, a comparative study was made on the three modes of ecological rehabilitation, i.e., gradual ecological rehabilitation based on realistic ability, ecological rehabilitation based on government dominancy, and conjugated ecological rehabilitation based on complex ecosystem theory. Scenario analysis indicated that conjugated ecological rehabilitation could achieve maximal ecological and social benefits with least socio-economic costs.

Key words: Root sourced signaling, Stomata, Model, Water use efficiency, Water saving