森林蓄积构成特征及其海拔梯度差异——江西武夷山黄岗山西北坡

The forest stock volume composition characteristics along altitudinal gradient on the northwest slope of Huanggang Mountain in Wuyi Mountain of Jiangxi Province

森林蓄积量是反映森林质量高低、物种丰富程度和生态服务功能优劣的重要依据。在江西武夷山自然保护区黄岗山西北坡选择无人为干扰的植被垂直带谱,设置5个海拔梯度（900~2 000 m）,开展森林蓄积构成特征及其海拔梯度差异分析。结果表明：黄岗山西北坡森林蓄积量达237.1 m3/hm2,不同植被类型构成了不同海拔梯度的林分蓄积。5个海拔梯度森林样带依次代表落叶阔叶林、常绿阔叶林、针叶林、混交林、矮曲林。不同海拔梯度的林分蓄积量差异显著（P〈0.05）,并在海拔梯度上呈先增大后减小的变化。将森林蓄积构成树种按植被类型分常绿和落叶两种,按叶型分针叶和阔叶两种,则发现海拔1 700~1 800 m以针叶和常绿树种为主,是林分蓄积量最大的分布区。常绿、针叶及阔叶树种的平均蓄积量在海拔梯度上均呈先增大后减小的变化。构成森林蓄积的优势科为松科和壳斗科,两科林分蓄积量占总蓄积量的59.76%。构成森林蓄积的主要树种是针叶树种南方铁杉（Tsuga chinensis var.tchekiangensis）和常绿阔叶树种多脉青冈（Cyclobalanopsis multinervis）,大多数优势科及优势种的蓄积量在海拔梯度上呈差异显著性（P〈0.05）。Pearson相关系数显示,蓄积量大小与海拔显著相关（P〈0.05）。研究结果表明：黄岗山西北坡森林蓄积以常绿树种为主,但不同海拔森林蓄积的构成及其差异性较大。

Forest stock volume is an important basis for reflecting forest quality, species richness and ecosystem service function. To study the forest stock composition and its relation to altitudinal gradient, five altitudinal gradients were selected in the vegetation vertical belt with no human disturbance on the northwest slope of Huanggang Mountain in Wuyishan Nature Reserve of Jiangxi Province（900 ~2 000 m）. Results showed that different altitudinal gradients forest communities were composed of different vegetation types, and the five altitudinal gradients forest samples plots respectively represented deciduous broad-forest, evergreen broad-leaved forest, coniferous forest, mixed forest and elfin forest. The total volume was569.1 m3, and the stock volume was 237.1 m3/hm2. Different altitudinal gradients forest stock volume showed a significant difference（P 0.05） and followed a first increase and then decrease trend. Stands were divided into evergreen and deciduous by vegetation types, and were divided into coniferous and broad-leaved by leaf types. Then altitudinal gradient 3（1 700~1 800 m） composed mainly of evergreens and conifers was the largest forest stock volume distribution zone. The mean forest stock volume of the evergreens, conifers and broad-leaved tree followed a first increase and then decrease trend in the altitudinal gradient. The main dominant families of the forest stock were Pinaceae and Fagaceae, whose volume was 59.76%of the total forest stock volume. The main dominant species were Tsuga chinensis var. tchekiangensis（conifer） and Cyclobalanopsis multinervis（evergreen broad-leaved tree）. However, there was a significant difference in the forest stock volume among the dominant families（P 0.05） and the dominant species（P 0.05）. Pearson correlation coefficients showed that the forest stock volume was significantly correlated with altitudinal gradient（P 0.05）. The results showed that the forest stock on the northeast slope of the Huanggang Mountain was mainly constituted by evergreens, but the forest stock composition and the forest stock volume showed a significant difference in the different altitudinal gradients.