The Ecosystem Service Functions Of Mangroves In Guangxi And Their Valuation

The environmental protection has been a hot spot all around the world. The work of"fixing a price"for the environmental resources, which is considered to be the basis work of environment protection, can provide a concrete and direct economic scale to measure the essence and value of natural resources. It is now being attended both domestically and internationally. This study is to"fixing a price"for the mangrove ecosystem resources in Guangxi in order to make their true values being widely recognized and to make a right choice to utilize them.Besides the selection of the related published literatures and the needed investigation, the contingent valuation method was also used, namely, an investigation on one's willingness to pay for maintaining the existence of mangroves in Guangxi. It is the first time for such a method being applied to the valuation of mangrove ecosystem resources in Guangxi. It is a real effective method to account the values of non-market public articles, such as the valuation on non-use values of Guangxi mangroves. At present, it is also the only method. In this study, valuation on non-use values was discussed explicitly on the design of CV questionary, of sampling, of CV test, of CV data Stat., of CV data analysis and so on. By the application of this method, to account the non-use values of Guangxi mangroves was doable. Even though that wasn't very accurate, we could get a value trend. Whereas there were many so uncertain factors in the courses of CV investigation that some biggish errors were difficult to avoid sometimes, and this circs should be attended to specially in this kind of study for the future.Guangxi is one of the main provinces where mangroves distribute in our country. There are 8374.9 hm2 of mangroves in Guangxi, about 10% accounting for all in China. The mangrove resources are very rich, there are 14 species of mangrove plants, belonging to 11 families and 14 genera. Among them, 10 species are true-mangrove trees and 4 species are semi-mangrove trees, furthermore, there are many other kinds of plant and animal resources. On the basis of a brief analysis of the natural general situation, flora, distribution, ecological characteristics of mangrove communities in Guangxi, the classification of ecosystem services and eco-value, the methods of assessment were systematically analyzed.According to Costanza's ecosystem services system, the functions of mangrove resources in Guangxi were divided into resource function, environmental function and culture function. Hereinafter, they were divided to practical production, promoting epeirogeny, vanishing from billow and protecting seashores, C fixing and O2 releasing, pollution treating, animals'habitat, entertainment and tour, etc. Value component of Guangxi mangroves contains use value and non-use value. The former includes the direct product value, direct serve value and indirect use value. The latter includes choice value, existence value, and heritage value. Valuation methods adopted were market valuation, replacement cost method, opportunity cost method, expert evaluating method, CVM (condition...