抚育间伐对白桦林物种多样性的影响

Effect of Thinning on Species Diversity of Betula platyphylla Plantation

为了探究抚育间伐对白桦林物种多样性的影响,对其抚育间伐前后物种多样性的变化进行调查与分析,结果表明:(1)经过抚育的白桦林的灌木层有较大的变化,原来的优势灌木毛榛、胡枝子、锦带花与六道木的重要值降低;而华北忍冬与三裂绣线菊的比例迅速增加。(2)抚育后林分的草本层有比较大的变化,其中银背风毛菊、牛蒡与玉竹的重要值降低,而银莲花与硬质早熟禾的比例迅速增加,这说明抚育间伐对林分草本层的影响较大,草本结构组成有明显变化。(3)经过抚育间伐林分灌木层与草本层的物种丰富度都有了提高,物种多样性也有了变化,其中灌木层的多样性降低,而草本层多样性增加;灌木层的均匀度下降,而草本层的均匀度增加。

In order to explore the effects of thinning on species diversity of Betula platyphylla plantation,the chan-ges of species diversity before and after thinning were analyzed.Result shows that:(1)The shrub layer of tended Betula platyphylla forest changed greatly.The important values of the original dominant shrubs,Corylus mand-shurica ybespedeza bicolor,Weigela florida&Abelia biflora all show that there are significant changes in the shrub layer of tended Betula platyphylla plantation.The ratio of Lonicera japonica and Spiraea trilobata increase rapidly.(2)After tending,the herbaceous layer of the stand change greatly.Among them,the important values of Trichosant.hes alba,Arctium lappa&Polygonatum odoratum decrease,while the proportion of Anemone cathay-ensis and Poa sphondylodes increase rapidly,which indicates that thinning hgfe greater impacts on the evenness of the herbaceous layer of the stand,and the aomposition of herbaceous structure have significant changes.(3)The species richness of the shrub layer&herb layer of the thinned plantation increase?and the species diversity also change.The diversity of the shrub layer decrease,while the diversity of the herb layer increase,the uniformity of the shrub layer decrease and the evenness of the herb layer increase.