川江防护林体系综合经济效益研究

采用净现值法对长江中上游川江段防护林体系的综合经济效益进行了分析评价。研究结果表明:长江中上游川江段防护林体系的综合经济效益由直接经济效益、间接经济效益和生态经济效益3部分构成。①在防护林体系的直接经济收益中,林副产品的收益现值为119.01亿元,占直接收益总现值的62%;木材收益的现值为57.01亿元,占直接收益总现值的29%;薪材收益的现值为16.84亿元,占直接收益总现值的9%。②在防护林体系的间接经济效益中,以评价期内,减少N、P、K损失数量货币化后值计,改良土壤的经济效益现值为7 447.57亿元,约占间接总效益的99%。以调蓄水量货币化值计,涵养水源的经济效益现值为36.92亿元,约占间接总效益的1%。③防护林体系内部产生的土壤改良和水源涵养效益在评价期内的现值就已达到7 484.794亿元,占综合经济效益的98%。如果再加上不能以货币表示的部分,改善生态环境的功效将更加巨大。④防护林体系的直接经济效益现值为192.86亿元,间接效益现值为7 484.59亿元,而投资费用现值53.07亿元,其综合经济效益的净现值高达7626.28亿元。在长江中上游川江段防护林体系中,投资较少的用材林和防护林占整个防护林面积的91%,而其他投资费用较高的林种只占9%,这也是形成净收益现值较大的一个重要原因。

Study on Integrated Economic Benefits of Chuanjiang Shelterbelt Forest System in Upper and Middle Reaches of Yangtze River

This paper discusses the meaning and relationships among various benefits of the shelterbelt forest in the view of economy,and puts forward an evaluation guideline including index system and some price parameters used in the evaluation such as the time limit,social discount,opportunity cost and so on,and analyzes and evaluates the integrated economic benefit of Chuanjiang shelterbelt forest ecosystem in upper and middle reaches of Yangtze River by the end of net value and data from the general investigation and typical monitoring in the above region.The results show:(1) The benefit of nonwood shares more among the total of direct benefits,while the benefits of lumber and firewood are following.According to the evaluation,the net value of nonwood benefit is 11.9 billion yuan,which shares 62% of the total net value of direct benefit,while that of the other two are respectively 5.7 billion yuan(29%) and 1.7 billion yuan(9%).(2)Among the indirect economic benefit,the benefit of land improvement is higher than that of water conservation.During the evaluation period,the amount of the quantities of N,P,K conserved is counted to be 744.8 billion yuan,sharing 99% of the total indirect benefit,and that of the carrying and sluicing water quantity is counted to be 3.7 billion yuan,sharing 1% of the total indirect benefit.(3) Construction of shelterbelt forest system in this region is mainly to improve its eco-environment.According to the calculation,the net value of land improvement and water conservation reaches 748.5 billion yuan,which shares 98% of the total integrative benefit.It shows that the shelterbelt forest system has notable effect on improving eco-environment.It will be greater if other benefits that could not be counted as money are added.(4)The shelterbelt system construction has a lower cost but a higher net benefit.According to the counted result,the direct economic benefit of shelterbelt forest system is 19.3 billion yuan,the indirect economic benefit is 748.5 billion yuan,and the net value of economic benefit is 762.6 billion yuan.In Chuanjiang shelterbelt forest ecosystem in upper and middle reaches of Yangtze River,the area of shelterbelt forest and the lumber forest share 91%,while other forest types with higher cost share only 9%,and this may be one of the important reasons that cause higher net value of economic benefit.