Mao Zhihong, Zhu Jiaojun, Tan Hui
Qingyuan Experimental Forest, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Ying Yong Sheng Tai Xue Bao. 2006 Aug;17(8):1357-64.
According to the distance from forest stands to residential area and the first and second grade roads, as well as the canopy density and the percentage of damaged trees, this paper defined the disturbances, anthropogenic and natural, as low, medium and high levels. On the basis of this, the effects of different level disturbances on the plant species diversity of secondary forest in montane regions of eastern Liaoning Province were analyzed, and the differences between the effects of anthropogenic and natural disturbances were discussed. The results showed that without considering forest types, the overall plant species diversity of secondary forest under medium level anthropogenic disturbance was higher than that under low and high level anthropogenic disturbances, with the Simpson indexes being 0.96, 0.95 and 0.92, and Shannon-Wiener indexes being 3.77, 3.60 and 3.36, respectively. The diversities of shrub and herb layers were also the highest under medium level anthropogenic disturbance, while the highest diversity of arbor layer was appeared under the high level one. Among different forest types, there existed differences in the plant species diversity under anthropogenic disturbances, e. g. , the diversity under medium level anthropogenic disturbance was the lowest in hard broad-leaved forests, but the highest in other forest types. In all test forest types, no consistent tendency was observed in the changes of three layers' diversities with anthropogenic disturbance levels, but the diversities of shrub and herb layers were greatly affected by the disturbances. After 3 years of snow/wind damage, there was no distinct difference in the diversities among the birch forests under low, medium and high level natural disturbances, with the Simpson indexes being 0.91, 0.91 and 0.92, and the Shannon-Wiener indexes being 2.30, 2.93 and 2.89, respectively. The diversities of arbor and shrub layers were both increased with the enhancement of natural disturbances, but there was no great difference in the diversity of herb layer among the three levels of natural disturbances. At present, anthropogenic disturbance mostly occurred in understory, while snow/wind damage occurred in canopy. Such dissimilarity could make the effects of environmental factors on plant species diversity differed greatly.
根据林分与居民区及一、二级道路的距离，以及郁闭度和树木受损比例，本文将人为干扰和自然干扰划分为低、中、高三个等级。在此基础上，分析了不同等级干扰对辽东山区次生林植物物种多样性的影响，并探讨了人为干扰和自然干扰影响的差异。结果表明，不考虑森林类型时，中等强度人为干扰下次生林的整体植物物种多样性高于低强度和高强度人为干扰下的，辛普森指数分别为0.96、0.95和0.92，香农-威纳指数分别为3.77、3.60和3.36。中等强度人为干扰下灌木层和草本层的多样性也最高，而乔木层多样性在高强度干扰下最高。在不同森林类型中，人为干扰下植物物种多样性存在差异，例如，中等强度人为干扰下硬阔叶林的多样性最低，但在其他森林类型中最高。在所有测试的森林类型中，三层多样性随人为干扰强度的变化未呈现一致趋势，但灌木层和草本层的多样性受干扰影响较大。经过3年的雪/风害后，低、中、高强度自然干扰下白桦林的多样性无明显差异，辛普森指数分别为0.91、0.91和0.92，香农-威纳指数分别为2.30、2.93和2.89。乔木层和灌木层的多样性均随自然干扰增强而增加，但三个等级自然干扰下草本层的多样性差异不大。目前，人为干扰主要发生在林下，而雪/风害发生在树冠层。这种差异使得环境因素对植物物种多样性的影响差异很大。
