石羊河下游人工梭梭林健康评价体系构建及应用研究

A health evaluation of a Haloxylon ammodendron plantation in the Shiyang River lower reaches

人工梭梭(Haloxylon ammodendron)林是石羊河下游分布最广、面积最大的人工固沙林,具有防风固沙、改良土壤、调节气候、增加碳汇等生态功能。近年来,人工梭梭林的普遍退化严重威胁着民勤绿洲的生态安全。因此,及时摸清人工梭梭林的健康状况,对人工固沙林的可持续经营具有重要意义。通过查阅文献及咨询专家(调查问卷),构建了5个一级指标和19个二级指标的人工梭梭林健康评价体系,采用AHP层次分析法和熵值法确定各指标的权重。基于野外调查数据,运用生态健康综合指数(HI),对人工梭梭林的健康状况进行评价,结果表明:石羊河下游人工梭梭林整体处于亚健康状态,健康指数值在0.50~0.67之间,均值为0.617。造成人工梭梭林处于亚健康的主要原因是群落结构不合理及生境因子的影响等,建议采取间伐、平茬以及围封等抚育管护措施来提高人工梭梭林的稳定性。

A Haloxylon ammodendron forest is a protected ecological forest in a desert area.It not only reduces the impact of wind sand disasters,controls soil erosion,and maintains the ecological stability of desert oasis but also improves soil quality and increases carbon storage of the desert ecosystem.Recently,the H.ammodendron forest has been declining in Minqin.Determining sustainable management of the artificial H.ammodendron forest is critical for the health status and function of wind prevention and sand fixation for this forest over time.In this study,the artificial H.ammodendron forest in the lower reaches of the Shiyang River was selected as the research focus.Through a literature review and expert consultation,a health evaluation system of the artificial H.ammodendron forest with 5 primary indicators and 19 secondary indicators was constructed.Analytic hierarchy process combined with an entropy method was used to determine the weight of each index.Based on the ecological health index(HI)and field survey data,the health status of the artificial H.ammodendron forest was evaluated.Results show the following:the HI value of the artificial H.ammodendron forest in the lower reaches of the Shiyang River is between 0.50 and 0.67;the average comprehensive HI is 0.617,which is in a sub-health state;and to improve the stability of the artificial H.ammodendron forest,we should take measures such as stubble and enclosure.