Grassland ecosystem services and their economic evaluation in qinghai-tibetan plateau based on RS and GIS

Abstract

Grassland ecosystem provides an array of benefits to human flat most of them are not generally accounted for in market transactions. From 1997, the researchers began to pay more attention to ecosystem services of grassland. Yet so far. the studies of grassland ecosystem services still locus on classification, characterization and general economic valuation owing to the limitation of method and technology. and therefore lack the studies of, dynamic changes and spatial textures that could influence tile economic valuation directly. It should be very helpful to use RS and GIS to assess the ecosystem services. Qinghai-Tibetan Plateau with unique geographical and climate characteristics plays an important role at Asian level and even at global level. Grassland occupies the largest area anions the ecosystem types in Qinhai-Tibetan Plateau. Because many rivers originate from this region, the grassland as the main ecosystem is not only tile product material but also the ecological protection belt. The irrational utilization of grassland over past two decades had induced severe degradation and thus the structure and ecological function of the fragile ecosystem had been damaged seriously. So in order to understand the ecosystem services of grassland overall, dynamically, and spatially, this paper aims to evaluate the ecosystem services and their valuation of grassland in Qinghai-Tibeten Plateau based oil RS and GIS. We choose six types of ecosystem services and derive six indicators from talent. They include: (1) providing NPP, by indicator of NPP; (2) carbon sequestration and oxygen release, by indicators of carbon and oxygen: (3) holding water, by indicator of soil moisture;(4) conserving soil, by indicator of land cover; (5) meliorating soil, by indicator of NPP: (6) maintaining biology diversity, by indicator of biodiversity. Six indicators above are calculated firstly by using MODIS 1B data and their reconstruction. 1: 4, 000, 000 Chinese Resources and Environment Database; and secondly composed the physical value unit area of every type of ecosystem services. Thirdly, we attempt to revise tile economic value unit area of grassland ecosystem services in terms of the physical value unit area, and then integrated physical values and economic values are evaluated for six types of ecosystem services. The evaluation shows that the ecosystem services and their economic values change with physically geographical conditions. In general they decrease front the southcast to the northwest gradually which suggests the ecosystem services and their economic values should he estimated based oil the spatial differentiation law.