川西南山地云南松林窗边界木偏冠现象与影响因素

树冠偏倚是树冠外部形态受生物学和非生物学因素综合影响的结果.该文研究了川西南山地阳性树种云南松的偏冠现象及其影响因素.云南松边界木偏冠现象普遍存在，树冠偏倚程度大于0.5的个体达到了95%(偏冠率1)和93%(偏冠率2).自然地理条件下，云南松边界木偏冠方向和方位可能有关，树冠偏向南方的边界木近80%，与地形和光照等非生物环境有关.云南松边界木偏冠程度受云南松自身特征的影响，偏冠率1和胸径、年龄、侧树间距、后树间距存在显著相关关系，和树高、枝下高间关系不显著.云南松偏冠受邻体树木分布影响，偏冠率2和侧树距离有关，和胸径、年龄、树高、枝下高、后树距离无显著相关关系.因此，云南松树冠偏倚程度受多种因素影响，受自身特征、邻体分布和非生物环境的相互作用. 

Crown inclination of Pinus yunnanensis gap border trees and the influencing factors in the mountain area of southwest of Sichuan, southwestern China

Crown inclination is the consequences of that the biological and its environmental factor synthetically influencing the exterior shape of crown. The crown inclination phenomenon and its influencing factors were investigated in this paper in the border trees of Pinus yunnanensis gaps in the mountain area of southwest of Sichuan Province, southwestern China. The crown inclination phenomenon is a general feature in the border tree of P. yunnanensis, the individual amount of crown inclination degree was bigger than 0.5, reached 95% (crown inclination 1 (shorted as RCI 1), averaged as 0.72±0.14（n=291，0.231～1）) and 93% (RCI2，averaged as 0.86±0.37（n=291，0.134～2.583）). Under the natural conditions, the orientation of P. yunnanensis crow inclination probably related to azimuth, and there were near 80% border trees, which were west orientation including southwest and northwest, implying that the degree of crow inclination related to the non biological factors such as topography and light. The degree of crow inclination of the border trees of P. yunnanensis gaps was influenced by individual feature and neighborhood distribution. The RCI1 significantly related to DBH, age, lateral tree intervals and back tree intervals, but not related to height and low branch height of border trees; the RCI2 was only obviously correlated with lateral tree intervals, not with DBH, height, age, low branch height and back tree intervals. Therefore, the degree of crown inclination of the border trees of P. yunnanensis gaps is influenced by individual feature, neighborhood distribution and non biological environment.