层次分析法在民勤绿洲农田防护林生态效益评价中的应用

Application of Analytic Hierarchy Process(AHP) in Eecological Benefit Evaluation of Farmland Shelterbelts in Minqin Oasis

基于防护林的定位观测数据,利用AHP法建立了防护林生态效益评价指数,并用该指数评价了民勤绿洲不同状态防护林的生态效益。结果表明,防风效益是决定民勤农田防护林的关键因素,林网内温湿度改变率、土壤有机质和土壤水分的改变率等因素对防护效益的影响也较大。防护林层次结构和疏透度是影响防护效益的主要参数。综合评价结果表明,疏透结构、林下乔灌草结构完整的林网防护效益相对较高,而通风结构或紧密结构、林下层次结构不完整的防护效益并不高。

A set of ecological benefit evolution index was established by method of Analytic Hierarchy Process （AHP） based on observation data in the farmland shelterbelts of Minqin oasis. It was found that the ecological benefit of farmland shelterbelts was predominantly determined by wind-defending benefit. Besides, change of temperature and humidity in shelterbelts, and variation of soil organic matter and soil moisture were also the important influencing factors. The wind-defending benefit has close relation with hierarchical structure and porosity of farmland shelterbelts. Results of integrated evaluation indicated that shelterbelts that have proper porosity and whole forest structure can well protect the farmlands in comparison with that have ventilation or tight structure and incomplete forest structure.