关键词: 城乡发展, 生态系统, 决策, 水分循环, 北京土石山区, 同位素, 侧柏, 栓皮栎

Abstract: This paper described the significance of urban rural development and its faced three issues on human population, environment and resources. In order to make the urban rural development on scientific basis, it is necessary to utilize the natural resources rationally, to protect the ecological environment well, and to balance the benefit/cost, structure and function of urban rural ecosystem.Such a system should be really constructed at a place, where its functions are full, environment is beautiful, production is growing, and life is comfortable.

Key words: Urban rural development, Ecosystem, Decision making, Quercus variabilis, water cycle, rocky mountain area of Beijing, isotope, Platycladus orientalis