武夷山常绿阔叶林冠层特性的海拔梯度变化

Variation of Canopy Characteristics of An Evergreen Broad-leaved Forest Along Altitudinal Gradient in Wuyi Mountain

2018年,在武夷山国家公园内选取典型的常绿阔叶林,在海拔800~1200 m区间内每隔100 m设置1个样地进行群落学调查和光特性测定。结果表明:平均树高、枝下高和冠层面积随海拔上升有增大的趋势,而胸径、冠幅体积、冠层厚度随海拔升高呈先上升后下降的趋势,叶面积指数随海拔升高有下降的趋势,叶倾角随海拔升高有增大的趋势且均以水平略向下的叶为主。各样地的无截取散射值都很小,且各海拔段没有明显差异。树高、冠幅半径与叶面积指数主要呈现为负相关性,冠层厚度与叶面积指数主要呈现为不显著的负相关性,胸径、冠层体积与各冠层光特性指数之间的相关性不显著。

In 2018,a typical evergreen broad-leaved forest was selected in Wuyishan National Park,and each plot was set up along 100 m altitude gradient of 800~1200 m to conduct community investigation and light characteristics determination.The results were as follows:the average tree height,under branch height and canopy size tended to increase along with the elevation,while the diameter at breast height,crown volume,crown layer thickness increased first and showed downward trend.The leaf area index(LAI)decreased with the increase of altitude.With the increase of altitude,the leaf inclination increased,and the leaves with slightly downward level were the main ones in each plots.The values of unintercepted scattering were very small and there was no obvious difference at different altitude.Tree height and canopy radius were mainly negatively correlated with leaf area index.Canopy thickness was mainly negatively correlated with leaf area index,and DBH and canopy volume were not significantly correlated with each canopy optical characteristic index.