基于信息熵的四川盆周山地杉木生态系统稳定性评价

Evaluation of ecosystem stability assessment of Chinese fir plantations in western hill area around the Sichuan basin based on entropy weight

【目的】四川盆周山地是成都平原的重要生态屏障,而维持人工林在四川盆周山地的稳定性对于该地区的生态环境质量至关重要。运用数学方法构建人工林稳定性评价模型一直是该领域的研究热点。信息熵在系统评价中应用广泛,但在森林生态系统稳定性评价方面尚未深入探索。【方法】通过分析杉木人工林生态系统稳定性各影响因素的特点,从结构和功能指标出发,以林分结构、物种多样性和土壤理化性质为评价指标主体,建立多级评价指标体系,并基于信息熵构建多级模糊评价模型,以彭州林场的杉木人工林为目标,杉木-柳杉混交林、人工-天然混交林、天然次生林为参照,进行综合评价。【结果】1、调查样地生态系统稳定性水平由高到低依次为:天然次生林、杉木-柳杉混交林、杉木纯林、人工-天然混交林。2、在一级指标中,土壤理化性质的权重值为0.3657,物种多样性为0.3266,林分结构为0.3077。3、在二级指标中,郁闭度(权重为0.2144)、林分密度(权重为0.2160)、土壤动物丰富度(权重为0.1905)、土壤动物Shannon-Wiener指数(权重为0.1827)和凋落物重量(权重为0.1982)等评价指标影响较大。【结论】土壤理化性质是影响杉木人工林生态系统稳定性的重要因素。基于信息熵的多级模糊评价模型能均衡考虑各评价指标的贡献,可应用于森林生态系统稳定性评价。

【Objective】The mountainous areas around Sichuan constitute important ecological shield of Chengdu plain.However,it is crucial to maintain the stability of plantation in the mountainous areas of Sichuan basin to realize high ecological environmental quality of the native area.The use of mathematical methods to construct artificial forest stability evaluation models has been a hot topic in this field.Based on multi-level fuzzy comprehensive evaluation model,entropy evaluation method was widely used in many systems,however,this method was rarely used in forest ecosystem.【Method】By analyzing the characteristics of influencing factors of ecosystem stability of plantations,and based on structure and function,we set up a multi-level evaluation index system taking soil physical and chemical properties,species diversity and plantation structure and built a multi-level fuzzy comprehensive evaluation model based on entropy weight method.The ecosystem stability of Chinese fir plantations in Pengzhou Forest Farm were evaluated compared with other forests(mixed plantations of C.lanceolata and C.fortune,natural mixed forests,and natural secondary forest).【Result】1、The order of stability level of the different forests were:natural secondary forest>mixed plantations of C.lanceolata and C.fortunei>C.lanceolata plantation and artificial>natural mixed forests;2、In the first-class indicators,the weight value of soil physical and chemical properties evaluation index was 0.3657,the weight value of species diversity evaluation index was 0.3266,and the weight value of forest structure evaluation index was 0.3077.3、Among the secondary indicators,canopy density(weight is 0.2144),stand density(weight is 0.2160),soil animal richness(weight is 0.1905),soil animal Shannon-Wiener index(weight is 0.1827)and Litterfall weight(weight is 0.1982)have greater impact.【Conclusion】Soil physical and chemical properties were important factors affecting the stability of plantation ecosystem.The multi-level fuzzy comprehensive evaluation method could precisely balance the different contributions of evaluation indices.Therefore,this model can be widely used to evaluate other type of forests.