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亚热带常绿落叶阔叶混交林是亚热带山地中重要的森林植被类型之一,是维持区域生态安全和保护生物多样性的重要屏障。为深入研究亚热带常绿落叶阔叶混交林中的生物多样性维持机理和动态过程,我们在湖北恩施七姊妹山国家级自然保护区6 ha亚热带常绿落叶阔叶混交林动态监测样地调查了所有胸径(DBH)≥1 cm的木本植物,分析了其群落组成、径级结构和优势种的空间结构特征。共记录到木本植物50,316株,其中独立个体有36,596株(去除分枝和萌生),隶属于57科124属245种,包括7种国家级保护植物和76种稀有种(每公顷个体数不超过1株)。样地内落叶物种分别占总物种数的61.2%(150种)和总个体数的52.6%(26,503株)。整个样地内植物个体胸径呈明显的倒“J”型分布,平均胸径为4.38 cm。样地小径级木本植物较多,胸径≥30 cm的木本植物仅175株。样地中重要值排名前4位的物种分别是川陕鹅耳枥(Carpinus fargesiana)、多脉青冈(Cyclobalanopsis multinervis)、交让木(Daphniphyllum macropodum)和缺萼枫香(Liquidambar acalycina)。这些优势种虽然在整个样地均有分布,但大径级个体(DBH≥10 cm)的空间分布差异较为明显。依据群落组成和径级结构特征,湖北七姊妹山森林动态样地属于人为干扰后处于自然恢复中期的森林群落。针对该样地开展长期的森林动态监测,将有助于深入了解亚热带常绿落叶阔叶混交林恢复过程中的群落构建规律和物种多样性维持机制。
The subtropical evergreen and deciduous broad-leaved mixed forest is one of the most important forest vegetation types in the subtropical mountainous area. It is an important barrier to maintain regional ecological security and protect biodiversity. In order to further study the mechanism and dynamic process of biodiversity conservation in subtropical evergreen and deciduous broad-leaved mixed forest, we investigated the dynamic monitoring of 6 ha subtropical evergreen and deciduous broad-leaved mixed forest in Qizimeishan National Nature Reserve, Enshi All woody plants with DBH ≥1 cm were analyzed for their spatial structure characteristics of community composition, diameter structure and dominant species. A total of 50,316 woody plants were recorded, of which 36,596 (excluding branching and initiation) were found in individuals belonging to 57 genera and 124 genera and 245 species, including 7 national protected plants and 76 rare species (individual per hectare not included) More than one strain). Species within the deciduous species accounted for 61.2% (150 species) of the total species and 52.6% (26,503 strains) of the total number of individuals respectively. The DBH of individual plants in the whole plots showed an obvious inverted “J” distribution with an average DBH of 4.38 cm. There are more woody plants in diameter and only 175 woody plants with DBH≥30 cm. The top 4 important species in the sample were Carpinus fargesiana, Cyclobalanopsis multinervis, Daphniphyllum macropodum and Liquidambar acalycina. Although these dominant species are distributed throughout the plot, the spatial distribution of large-diameter individuals (DBH≥10 cm) is more obvious. According to the characteristics of community composition and diameter structure, the forest dynamic sample plot of Qizimei Mountain in Hubei Province belongs to the forest community in the middle stage of natural recovery after anthropogenic disturbance. Long-term forest dynamic monitoring of the site will help to understand deeply the rules of community establishment and species diversity maintenance in the process of restoration of subtropical evergreen and deciduous mixed forest.