雾灵山落叶阔叶林采伐迹地物种多样性和植物种群动态变化研究

Species diversity and population dynamics of plants on deciduous broad leaved forest slash at Wuling Mountain

在对永久样地连续５ 年定位观测的基础上，应用Ｓｈａｎｎｏｎ 物种多样性和均匀度指数，研究了雾灵山落叶阔叶林采伐前后更新苗木、草本植物和灌木群落的物种多样性、群落均匀度和种群动态变化．结果表明，在林分采伐后的４ 年内，迹地上苗木的物种多样性和群落均匀度指数均高于伐前林分．从无到有并迅速繁衍的树种为山杨，伐前林分中有林木存在，但迹地上缺乏幼苗的树种为油松．灌木的物种多样性和均匀度指数呈增加趋势．始终处于优势的树种为锦带花和胡枝子，后期迅速繁衍的树种为山楂叶悬钩子．草本植物的物种多样性和群落均匀度指数均是在林分采伐后第３ 年达到最大值，第４ 年开始下降．主要草本植物种群的动态变化可归纳为８ 种类型．阳性植物充分发育，阴性或耐荫植物逐渐衰退，是草本植物种群最明显的表现．

Based on five years consecutive located observations at permanent plots, the species diversity, community evenness and population dynamics of regenerated seedlings,herbs and shrubs before and after clearcutting of the deciduous broad leaved forest at Wuling Mountain were studied by using Shannon Wienner's species diversity index and the evenness index. The species diversity and evenness indexes of tree seedlings on the slash were higher in 4 years after cutting than before cutting, Populus davidiana not existed in the uncut forest stands quickly propagated, while Pinus tabulaeformis existed in the uncut forest stands was absent on the slash. The species diversity and evenness indexes of shrubs increased on the slash. Weigela florida and Lespedeza bicolor were the dominant species. Rubus crataegifolius, which was not dominant at the beginning,increased rapidly in the later period, and became dominant on the slash. The species diversity and evenness indexes of herbs peaked in the third year, and began to decrease in the fourth year. The herbaceous plants were classified into 8 types, based on their population dynamics before and after forest cutting. The light demanding species developed well, and the shade enduring species gradually disappeared,which were the obvious characteristics for herbaceous populations.