黄山亚热带常绿阔叶林的群落特征

Community characteristics of a subtropical evergreen broad-leaved forest in Huangshan, Anhui Province, East China

黄山是我国东部高山之一,处于亚热带季风气候区,属南北植物区系交替的过渡带,是第四纪冰期动植物的避难所。其地带性植被为常绿阔叶林,植被垂直分布明显,是中国生物多样性保护优先区域,也是世界文化与自然遗产地以及享誉全球的风景名胜区。2014年,我们在黄山建立了10.24 ha的森林动态监测样地,并完成了首次调查。本文从物种组成、区系特征、径级结构和空间分布格局等方面分析了样地中植物的群落特征。结果表明:样地内有维管植物59科129属191种,其中乔木层内胸径≥1 cm的木本植物46科97属153种;热带性质的科、属分别占总科、属数的65.79%和45.36%,温带性质的科、属分别占34.21%和51.55%。样地内珍稀濒危物种较多,其中国家Ⅱ级重点保护野生植物6种、《中国生物多样性红色名录——高等植物卷》中的近危物种7种、《濒危野生动植物种国际贸易公约》(CITES)附录Ⅱ物种1种以及64种中国特有种,这些物种具有较高的保护和研究价值。当取样面积小于2,150 m^2时,物种数随着面积的增加而急剧增加;其后增加速率明显降低;但大于57,950 m^2时,增加速率又略变大。稀有种69种,占总树种数的45.10%。壳斗科和杜鹃花科的重要值占一半以上。建群种甜槠(Castanopsis eyrei)的重要值达26.25%,其次分别为细齿叶柃(Eurya nitida)(7.63%)、马银花(Rhododendron ovatum)(7.60%)、马尾松(Pinus massoniana)(6.29%)和檵木(Loropetalum chinense)(4.83%)。样地平均胸径为4.10 cm,小径木的数量占较大优势。乔木层可分为两个亚层,甜槠在两个亚层的个体数量均最多,马尾松数量也比较多。甜槠、细齿叶柃、马银花、马尾松等均呈较显著的聚集分布。

Located in the subtropical monsoon climate zone, Huangshan is one of the high mountains in eastern China and lies in the transition zone of north-south flora. It is considered a refuge of flora and fauna during the Quaternary maximum glaciation. Zonal vegetation is classified as evergreen broad-leaved forest with a vertical distribution pattern. It is not only one of China＇s Biodiversity Conservation Priority Areas, but also one of the World＇s Cultural and Natural Heritage Sites and a world famous scenic spot. In 2014, we established a large-scale forest dynamics plot with an area of 10.24 ha in Huangshan based on international protocols（Smithsonian Tropical Research Institute, Center for Tropical Forest Science, CTFS） and completed the first field survey. The investigation aimed at revealing community characteristics by analyzing species composition, flora characteristics, diameter class structure, and spatial distribution patterns. We recorded 191 species of vascular plants, belonging to 59 families and 129 genera, in the plot. Among these, trees（DBH ≥1 cm） belonged to 46 families, 97 genera and 153 species. The number of family and genera with tropical distributions accounted for 65.79% and 45.36% of the total taxa, respectively, while those with temperate distributions accounted for 34.21% and 51.55%, respectively. A number of rare and endangered species occurred in the plots, including six species classified as Class Ⅱ of State Key Protected Wild Plants, seven threatened species（VU） from the China＇s Biodiversity Red List： Higher Plant, one species defined in the Convention on International Trade in Endangered Species of Wild Fauna and Flora（CITES）（Appendix Ⅱ）, and 64 endemic species to China, indicating their values for protection and research. We also found that the number of species increased sharply with increasing scale when the scale was less than 2,150 m^2, while at a higher resolution its rate of increase decreased significantly. When the scale was larger than 57,950 m^2, the rate of increase declined slightly. Rare species（N = 69, less than 1 ind./ha） reached 45.10% of the total number of individuals. Members of Fagaceae and Ericaceae comprised more than half of the total importance values（IV）. The IV of Castanopsis eyrei, a constructive species, was 26.25%, and followed by Eurya nitida（7.63%）, Rhododendron ovatum（7.6%）, Pinus massoniana（6.29%） and Loropetalum chinense（4.83%）. The mean DBH for all the individuals was 4.10 cm, and small sized trees dominated the plot. The emergent layer was divided into two sub-layers, individuals of C. eyrei were dominant in both layers, while P. massoniana was a subdominant species. Castanopsis eyrei, E. nitida, R. ovatum and P. massoniana had a significant clustered distribution.