华北落叶松天然林林隙冠层特征对更新的影响

Effect of Gap Canopy Characteristics on Stand Regeneration of Larix principis-rupprechtii Natural Forest

探讨山西省庞泉沟国家级自然保护区华北落叶松天然次生林林隙冠层及光因子对林下更新的影响。对38个林隙内幼木每木检尺(基径),测定树高、冠幅,林隙的冠层结构与边缘木特征,利用鱼眼相机拍摄冠层图像共266张。使用Gap Light Analyzer软件对采集的冠层图像进行数据化处理,得到冠层开度、叶面积指数、林隙总辐射、直接辐射、散射辐射等冠层特征指标,并采用Pearson相关性分析法分析林隙冠层结构及光环境与华北落叶松幼苗更新关系。结果表明,林隙中冠层结构和光因子与华北落叶松的更新特征呈显著正相关(P<0.05);不同等级林隙内冠层结构与光因子对华北落叶松幼苗的相关性存在较大的差异,在大林隙(110~150 m^(2))内表现出最显著的相关性。所有林隙的冠层开度介于24.87%~38.00%的样本率为79%,总辐射介于13%~21%的样本率为79%。华北落叶松林隙内冠层结构和光因子对华北落叶松幼苗的生长有显著影响,其中面积110~150 m^(2)的林隙最适合华北落叶松幼苗的生长发育。

The objective of this study was to understand the effects of gap canopy and light factors on the understory regeneration of Larix principis-rupprechtii natural secondary forest occurring in the Pangquangou National Nature Reserve,Shanxi Province.Young trees in 38 forest gaps were measured based on tally method(base diameter)to obtain the data of the tree height,crown width,canopy structure,and edge wood characteristics of the forest gap.Totally,266 canopy images were taken with a fish eyeglass camera.The collected canopy images were quantified using Gap Light Analyzer software to obtain canopy characteristics indexes,such as canopy opening,leaf area index,total gap radiation,direct radiation,and scattered radiation.Pearson correlation analysis method was used to analyze the relationship between canopy structure,light environment,and L.principis-rupprechtii sapling regeneration.The results showed that the canopy structure in the forest gap was significantly and positively(P<0.05)correlated with the regeneration characteristics of L.principis-rupprechtii forest.Significant differences in correlations between the canopy structure,light factor and the sapling growth of L.principis-rupprechtii were observed.Significant correlations were found in the large forest gaps(110-150 m^(2)),The sample rate of canopy opening between 24.87%and 38.00%in all gaps was 79%.The sample rate of total radiation between 13%-21%was 79%.Canopy structure and light factors in the gaps of L.principis-rupprechtii forest present significant effects on the growth of L.principis-rupprechtii seedlings,and the gaps with the area of 110 m^(2)-150 m^(2) are the most suitable for the growth and development of the seedlings.