辽西油松林水土保持效益评价

利用101块样地的调查资料，采用综合因子评价方法评价了辽西油松水土保持林的生态效益，把辽西油松水土保持林划分为低效、较低效、中效、较高效、高效五个等级：其中牛河梁地区的油松人工林大都为低效林，欺天林场的油松人工林大都为中效林，南刘杖子林场的天然次生林大都为高效林。这一研究结果将为辽西油松水土保持林生态系统管理提供重要的科学依据。

Assessment of ecological benefits of Chinese pine in soil and water conservation forests in Western Liaoning Province

In this paper, the ecological benefits of Soil and Water Conservation Forests planted with Chinese pine (Pinus tabulaeformis) were assessed for 101 plots in Western Liaoning Province by using the comprehensive-index assessment method. The comprehensive-index assessment method is an indirect but effective method used for estimation, especially when the main functional indices are difficult to measure. In order to use this method, a system of estimation indices assessing the ecological benefits of forests was designed for Western Liaoning, including estimation criteria and classification of benefits. The types of forest ecological benefits were classified based on the weight value of every index (by Analytic Hierarchy Process, i.e. AHP) and the comprehensive estimate index (from the survey materials of forest stands).The Soil and Water Conservation Forests of Western Liaoning Province were divided into five classes using the comprehensive-index assessment method: lower-benefit forest, low-benefit forest, middle-benefit forest, high-benefit forest and higher-benefit forest. Most forests of the Niuheliang, Qitian, and Nanliuzhangzi regions were classified as low-benefit, middle-benefit, and high-benefit forests respectively. In Niuheliang region, lower-benefit, low-benefit and middle-benefit forests accounted for 79.4%, 14.7% and 5.9% respectively. In Qitian region, lower-benefit forest, low-benefit and middle-benefit forests were 4.5%, 22.7%, 72.7% respectively. In Nanliuzhangzi region, high-benefit and higher benefit forests were 16.7% and 83.3% respectively. The results showed that forest structural integrity (especially the forests' layer structure) has a great significance in the ability of Soil and Water Conservation Forests to provide ecosystem services. In particular, a key task for ecosystem management in these pine forests is the conservation of the herbage layer and the litter layer on the forest floor. The policy of forest protection should be adopted as an effective approach for ecosystem management in Soil and Water Conservation Forests planted with Chinese pine in Western Liaoning Province.