胸径和林分密度决定内蒙古东部落叶松林种内竞争  

DBH and stand density regulate intraspecific competition of Larix gmelinii in eastern Inner Mongolia

作　　者：刘怡青 田育红[1] 宋含章 黄薇霖[1] 

机构地区：[1]地表过程与资源生态国家重点实验室,北京师范大学资源学院,北京100875

出　　处：《生态学杂志》2018年第3期847-853,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金重点项目(41530747)资助.

摘　　要：种群竞争是森林衰退和恢复保护的主要影响因素之一。通过对内蒙古东部半干旱区落叶松人工林293株对象木进行调查,用Hegyi单木竞争指数模型分析个体水平和样地水平上的种内竞争强度,并探讨其影响因素。结果表明:研究区落叶松人工林的竞争强度随着对象木胸径的增大而变小,并且两者关系服从幂函数;Pearson相关分析显示,个体水平上的竞争指数与树高、冠幅呈显著的负相关关系,与树木衰退程度呈显著的正相关关系;多元线性回归模型分析显示,林分密度是影响样地水平上种内竞争最重要的因素。本研究为研究区频繁出现的森林衰退现象及其驱动机制研究提供了重要依据。Competition is one of the main drivers for forest decline and restoration. In this study, we investigated 293 target trees in aLarix gmeliniiplantation in a semiarid area of eastern Inner Mongolia. We used Heygi individual competition index model to quantify the competition intensity at both individual and plot levels and analyzed the determinant factors. Results showed that the competition intensity ofL. gmeliniidecreased with the increases of diameter at breast height （DBH）. Their relationship followed the power function. Results from Pearson’s correlation analysis indicated that individual competition index was negatively correlated with tree height and crown width, and positively correlated with tree decline index. A multiple linear regression model analysis demonstrated that the competition intensity at the plot level was mainly influenced by stand density. Our results had implications for uncovering the mechanism for the forest decline in eastern Inner Mongolia.

关 键 词：内蒙古东段 落叶松 种内竞争 个体水平 样地水平 

分 类 号：S718.5[农业科学—林学]