不同林分林下植被的多样性特征及生物量研究

Research on Diversity and Biomass of Undergrowth Vegetation in Different Forest Stands

对承德市山区土壤含水率与不同林分林下草本层植物生物量和物种多样性的相互关系进行了研究,结果表明,在5种森林群落类型中,土壤含水率的高低顺序为油松-落叶松混交林>落叶松中龄林>落叶松幼龄林>油松成熟林>油松幼龄林,其林下草本层的地上生物量表现为油松-落叶松混交林大于油松纯林、落叶松纯林,在纯林中也随着土壤含水率的增加生物量增大。对土壤含水率与林下草本植物物种多样性进行相关分析,结果表明,林下草本植被在林分处于幼龄林时期,土壤含水率对林下草本植物物种多样性的增加起到了促进作用;随着林分的成熟,土壤含水率虽然增加,但对林下草本植物物种多样性的促进作用逐渐丧失。在油松-落叶松混交林中土壤含水率虽然较高,但对林下草本植物物种多样性却产生了抑制作用。

The relationship of soil moisture with biomass and species diversity of undergrowth vegetation in mountainous area of Chengde city was studied.The results showed that the soil moisture in the 5 forest stands ranked from high to low as Larix gmelinii（Rupr.） Rupr.-Pinus tabulaeformis Carr.mixed forest,middle-aged forest of L.gmelinii,young forest of L.gmelinii,mature forest of P.tabulaeformis,young forest of P.tabulaeformis.The aboveground biomass of understory herbaceous layer in L.gmellini-P.tabulaeformis mixed forest was greater than that in pure P.tabulaeformis forest or L.gmellini forest.The biomass increased with the increase of soil moisture in pure forests.Correlation analysis on soil moisture and understory herbaceous species diversity showed that soil moisture promote the increase of on understory herbaceous species diversity during young forest period.Soil moisture would increase as the forest matured;however,its effect on understory herbaceous species diversity might gradually lose.Soil moisture was high in L.gmellini-P.tabulaeformis mixed forest,but it had inhibitory effect on the understory herbaceous species diversity.