牛洛河自然保护区东京龙脑香林群落特征研究

东京龙脑香(Dipterocarpus retusus)是国家I级重点保护野生植物,是东南亚热带雨林的标志性树种,目前有关该群落学的研究尚处于空白。该研究通过实地踏查,采用典型选样法布设4个30 m×30 m的群落样地、20个10 m×10 m的种群样方,记录样地内的物种及其株高、胸径、数量,群落特征等,并通过分布区类型划分、群落物种多样性分析及种群年龄结构划分等方法,分析了东京龙脑香林群落学与种群学特征。结果表明:(1)样地中共记录种子植物181种,隶属76科143属,其中热带性质科有58科、热带性质属有126属、热带性质种有162种,科、属、种热带成分比例分别为76.32%、88.11%、89.50%,表明该群落具有强烈的热带性质。(2)该群落物种多样性指数整体较高,多样性指数(d_(Ma)、H')在群落不同层次中均表现为灌木层乔木层草本层的特征;均匀度指数(J_(sw))在不同层次中比较接近;优势度指数(D)表现为草本层乔木层灌木层。(3)从乔木层重要值来看,东京龙脑香的最大,为26.85,显示出绝对的优势,是该群落的优势种、建群种。(4)该种群年龄结构为正金字塔型,表明该种群处于增长时期,为增长型种群。

Community characteristics of Dipterocarpus retusus forest in Niuluo River Natural Reserve

Dipterocarpus retusus is a national key protected wild plant. It is the representative species in tropical rainforest of Southeast Asia. Our study aimed to elucidate the community characteristics of D. retusus forest which was not yet studied before. Four community plots(30 m × 30 m)and 20 population plots(10 m × 10 m)were typically sampled in the D. retusus forest distributed in Niuluo River Natural Reserve in Jiangcheng County. The height, DBH(diameter at breast height), numbers and community characteristic of all the spermatophyte species were recorded. We evaluated the distribution types, species diversity and population age structure. The results were as follows:(1)181 spermatophyte species belonging to 143 genera, 76 families were recorded. D. retusus community was dominated by tropical floristic elements, of which 58 families, 126 genera and 162 species all belonged to tropical flora and the ratios were as high as 76.32%, 88.11% and 89.50%, respectively.(2)Species diversity indices varied in different stand layers: Richness index and Shannon-Wiener diversity showed shrub layer>tree layer>herb layer, while Simpson index showed opposite trend shrub layer<tree layer<herb layer and Pielou index is similar in different stands.(3)D. retusus is the dominant species in the community with the highest important value of 26.85 in tree layer.(4)The age structure of D. retusus population had a positive pyramidal type, which indicates that the population structure is growing.