Water conservation of forest ecosystem in Beijing and its value

Under a scenario of global climate change, the water conservation function of Beijing's forest ecosystems has attracted considerable public attention. In this paper, the term of water conservation is described as a comprehensive regulation of forests on water resources through various hydrological processes, and grouped into three services, i.e., rainfall interception, soil water storage and fresh water provision. On the basis of Beijing's forest resource survey data and mathematical simulations, the function and the economic value of water conservation was estimated. The result showed that, the forest ecosystems of Beijing could intercept approximately 1.43 billion cubic meters of rainfall and 277.82 million cubic meters of soil water under ideal conditions, and supply 286.67 million cubic meters of fresh water, their economic values were estimated to be about 2.77 billion RMB(Chinese Currency, 8.28RMB = US$1), 2.15 billion RMB, and 315.33 million RMB, respectively. The total economic value of water conservation provided by Beijing's forests was 5.23 billion RMB, and the economic benefit per hectare was equal to 5704 RMB. Furthermore, the spatial variation of water conservation functions and the monetary values of the main forest ecosystems in different locations in Beijing were analyzed, and the effects of water conservation provided by the forest ecosystem on the development of society and economy in Beijing were discussed. This work contributes to the realization and preservation of forest resources in Beijing.