旅游区人为干扰对森林群落物种多样性的影响

研究人为干扰对湖北省梭布垭石林针阔混交林森林群落物种多样性的影响。结果表明，人为干扰对乔木层马尾松Pinus massoniana和杉木Cunninghamia lanceolata优势种的主体地位和作用没有根本性的改变，但使群落平均胸径（或地径）和平均树高降低，群落种类组成发生变化。重度干扰和中度干扰降低了群落乔木层阔叶树种和灌木层优势种的作用和地位，重要值降低，但增加了群落物种多样性水平。不同干扰类型的群落，在垂直高度1.0 m以下，Shannon-Weiner多样性指数较大，1.1 ~ 3.0 m高度达最大，以后随高度升高，多样性指数降低，在9.1 m以上的高度层，树种单一，多样性为０。图3表3参13

Effects of human disturbance on species diversity of Pinus massoniana-Cunninghamia lanceolata mixed forest in Suobuya Stone Forest

The effects of human disturbance on species diversity of natural mixed stand of conifer and broad-leaved trees in Suobuya Stone Forest were discussed in this paper.The results showed that the human disturbance didn't change the dominant positions and roles of Pinus massoniana and Cunninghamia lanceolata in arbor.But it decreased the average diameter at breast height(or basal diameter)and average tree height and changed the species composition.The medium and light disturbance lowered the roles and positions of the broadleaved tree in arbor layer and the dominant species in shrub layer and hence lowered their important values,but it increased the diversity of community species.Of the communities under disturbance,the Shannon-Weiner diversity index was larger when the vertical height was below 1.0m and the largest between 1.1m to 3.0m.Then the diversity index decreased with the height.There wag no diversity when the height was over 9.1m.