油松树干径向生长的时空变异特征

为研究油松树干径向生长的时空变异规律,选择99年生油松(Pinus tablaeformis)进行树干解析及树轮宽度测定。结果表明:油松不同生长阶段的直径生长率的垂直变异差别很大。整个生长期内,直径平均生长率随树高增加先增后降,差异显著;生长初期表现为先减—后增—再减模式,差异显著,而生长后期无明显差别。生长过程中,不同部位直径年生长量、累计生长量随形成层年龄增加变化不尽相同,树干基部年生长量为增加-稳定-下降型,胸高处为先增后降型,稍部为先降后增型,其余部位多数为持续下降型;所有部位累计生长量均随形成层年龄增加而增加,二者关系随树高增加依次表现为显著的Logistic函数、二次函数及线性函数关系。

Spatial and Temporal Variation in Stem Radial Growth of Pinus tablaeformis

To illustrate the spatial and temporal variation in stem radial growth of Pinus tablaeformis,we chose 99-a P.tablaeformis trees to conduct stem analysis and ring measurement.The vertical variations in mean diameter growth rate varieel greatly over the growth process;it was first increased and then decreased with increasing tree height significantly during 99 a,and first increased,then decreased and increased again significantly in the early growth stage,and had no differences in the late growth stage.Over the growth process,the variations in yearly and accumulative diameter increment in different tree heights with increasing cambial age were not similar,the variation pattern of yearly increment was increase-stabilization-decrease with increasing tree height at the stem base,first increased and then decreased at breast height,first decreased and then increased at treetop,and continuously decreased at other stem positions.The accumulative increment was increased with the increasing cambial age at all sampled stem positions,the relationships between them was significant for logistic,quadratic,and linear function,respectively,with the increasing tree height.