对西洞庭湖区主要森林景观类型的林下灌木层和草本层进行物种多样性的调查分析。将综合评价法与熵权法相结合得到物种多样性综合指数,衡量不同森林景观林下物种多样性综合水平,根据各指标权重值,找出影响本研究区物种多样性水平的主要因子。结果表明,不同森林景观林下草本层Simpson指数在0.793 0~0.916 1之间,Shannon-Wiener指数在1.759 6~2.717 6之间,在杉木幼龄林景观中最高,在竹林中最低。灌木层Simpson指数在0.794 2~0.927 7之间,Shannon-Wiener指数在1.869 9~2.909 0之间,在阔叶林景观中最大,竹林中最小,整体上灌木层高于草本层。物种多样性综合指数在0.012 3~0.829 4之间,在阔叶林景观中最大,竹林中最小。林下灌草物种丰富度水平低和草本层物种均匀度水平低是影响研究区竹林、灌木林等景观林下物种多样性水平的主要因子。

This paper presented the investigation and analysis on the species diversity of shrub layer and herb layer in the main forest landscape types in West Dongting Lake.Comprehensive evaluation method and entropy weight method are combined to get the comprehensive indexes of species diversity,and the comprehensive level of species diversity in different forest landscapes was measured.According to the weight value of each index,the main factors affecting the level of species diversity in the study area were found out.The results show that the Simpson indexes of herb layer were 0.793 0~0.916 1.The Shannon-Wiener indexes of herb layer were 1.759 6~2.717 6.The young Chinese fir forest landscape is the highest and the bamboo forest landscape is the lowest.The Simpson indexes of shrub layer were 0.794 2~0.927 7.The Shannon-Wiener indexes of shrub layer were 1.869 9~2.909 0.The broad leaved forest landscape is the highest and the bamboo forest landscape is the lowest。The species diversity index of shrub layer was higher than that of the herb layer as a whole.The comprehensive index of species diversity in different forest landscapes was 0.012 3~0.829 4。The broad leaved forest landscape is the highest and the bamboo forest landscape is the lowest.The low level of species richness and evenness of herb layer was the main factors influencing the level of species diversity of different forest landscapes in the study area,such as bamboo forest,shrub forest,and so on.