Value of Ecosystem Services and Its Assessment Methodology

The services of ecological system and their natural capital stocks involved are critical to the function of the Earth's (life-support) system. The ecosystem services contribute to human welfare, both directly and indirectly, and therefore represent a part of the total (economic) value of the global, state and regional economy system. In order to manage the natural capital and ecosystem effectively, (reasonable) assessment methodology and criteria of multi-dimension at different scale should be built. On the basis of reviewing (literatures) and studies on ecosystem services, this paper generalizes the definition and functions of ecosystem services, and sums up the principles of ecosystem service assessment. Some problems in the assessment methods,rationality of ecosystem services value, and the temporal and spatial heterogeneity of value of ecosystem services are also discussed.