不同人为干预方式对子午岭植物群落组成及多样性的影响

摘要

Four types of vegetation community were selected as research objects from three forest stands,i.e.,natural secondary forest,artificial near-natural restoration forest,and plantation occurring in Ziwuling (Meridian Ridge of Loess Hilly) area.The influence of different human intervention measures to the changes of vegetation community composition and species diversity were studied.The results showed that 1) the species composition of plant community in this area was mainly of single species,and there was no obvious tendency of species distribution,and the distribution of species composition was relatively diverse.2) The quantity proportion of different vegetation types (arbor,bush,and grass) in the study area was equivalent,the key constructive species were Pinus tabuliformis of Pinaceae,Quercus wutaishanica of Fagaceae,from which the vegetation communities were constructed with other plants,such as Carex lanceolata of Cyperaceae,Tripolium vulgare of Compositae,Spiraea pubescens and Rosa xanthina of Rosaceae.3) Different human interventions demonstrated significant differences on species diversity.The community diversity for natural secondary forest and near-natural control restoration forest with less intervention was mixed forest ＞pure forest,broadleaf forest＞coniferous forest.The species diversity of the plantation with intensive intervention showed the characteristics of pure forest＞mixed forest.4) The influence of human intervention on different community layers was different.With the increase of human intervention intensity,the species richness,Shannon-wienner index and Pielou index of arbor layer decreased,while the herbaceous layer showed the opposite characteristics,and the human intervention had relatively little effect on the shrub layer and had no obvious consistency.%选择黄土丘陵区子午岭不同人为干预措施下的天然次生林(NS)、近自然改造林(AN)和人工林(PL)3种林分的4种群落类型为研究对象,探讨不同人为干预措施对区域植被群落组成及物种多样性变化的影响.结果表明,1)研究区植物群落的物种组成以单物种的科、属为主,物种数量分布并无明显的趋向性,物种组成的数量分配相对多样;2)研究区植物群落乔、灌、草数量比例相当,以松科的油松、壳斗科的辽东栎为群落的主要建群种,与莎草科的大披针苔草、菊科的碱菀及蔷薇科的土庄绣线菊、黄刺玫共同构建了区域主要的植物群落;3)不同人为干预措施对群落物种多样性的影响差异明显,无人为干预的天然林和干预较小的自然改造林群落多样性,均表现为混交林＞纯林、阔叶林＞针叶林的一致性特征,而干预强度较大的人工林多样性则表现出纯林＞混交林的特征;4)人为干预对群落各层片的影响不一,随人为干预强度的增大,乔木层物种丰富度、香农多样性、均匀度、优势度均表现为减小的变化特征,而草本层则表现出相反变化特征,人为干预对灌木层片影响较小且无明显的一致性.