Zhao Liang, Yang Zhi-Chun, Zhou Juan-Hua, Wang Guo-Qiang, Yin Qiu-Long, Zhao Jin, Qi Guang, Yuan Zuo-Qiang
Louguantai National Experimental Forest Farm in Shaanxi Province, Zhouzhi 710400, Shaanxi, China.
School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China.
Ying Yong Sheng Tai Xue Bao. 2023 Dec;34(12):3214-3222. doi: 10.13287/j.1001-9332.202312.001.
We investigated species composition and community structure of a typical natural secondary forest in the northern foothills of the Qinling Mountains, within the dynamic monitoring plot of deciduous broad-leaved forest at the Louguantai experimental forest farm in Zhouzhi County, Shaanxi Province. The results showed that there were 3162 individual woody plants with diameter at breast height ≥1 cm in the plot, which were belonged to 42 species, 36 genera, and 25 families. The community genus's areal type was dominated by the temperate component, which accounted for 44.4%, and followed by the tropical component. The community was dominated by several tree species. The top three species with respect to importance value were , , and , with the sum of their importance value being 64.7%. The average DBH of all woody plants was 7.58 cm. The distribution of all individuals and dominant species in the tree layer was approximately normal, with more medium-size individuals. The community structure was stable. The community was poorly renewed, with a trend of population decline. Biodiversity indices varied considerably among different plots, being lower than those of subtropical broad-leaved evergreen forests. There was a significant correlation between community species distribution and environmental factors. Soil and topography explained 42.4% of the variation in community distribution. Altitude and soil alkali hydrolysable nitrogen had a significant effect on community distribution. Altitude, soil total phosphorus, and organic matter content significantly affected the species diversity of communities. The stronger adaptability of populations allowed them to become dominant in low-nutrient environments, which limited species diversity in the community.
我们对陕西省周至县楼观台实验林场落叶阔叶林动态监测样地内秦岭北麓典型天然次生林的物种组成和群落结构进行了调查。结果表明，样地内胸径≥1厘米的木本植物个体有3162株，隶属于25科36属42种。群落属的分布区类型以温带成分占优势，占44.4%，其次为热带成分。群落以几种乔木树种为主。重要值排名前三的物种为 、 和 ，它们的重要值之和为64.7%。所有木本植物的平均胸径为7.58厘米。乔木层所有个体和优势种的分布近似正态，中等大小个体较多。群落结构稳定。群落更新不良，有种群衰退趋势。不同样地间生物多样性指数差异较大，低于亚热带常绿阔叶林。群落物种分布与环境因子之间存在显著相关性。土壤和地形解释了群落分布变异的42.4%。海拔和土壤碱解氮对群落分布有显著影响。海拔、土壤全磷和有机质含量显著影响群落的物种多样性。 种群较强的适应性使其在低养分环境中成为优势种，从而限制了群落的物种多样性。
