摘要
选择川西地区代表性云杉(Picea asperata)人工纯林,研究了林分中不同生长状态云杉个体径向生长过程,建立了树轮标准年表(STD),揭示了径向生长与气候因子的关系.评估了林窗疏伐措施应用后的径向生长量释放效应.结果表明:(1)云杉个体径向生长过程可分为快速生长期(1982-1993)和生长减慢期(1994-2005)两个阶段,优势木年平均径向生长量显著大于劣势木;(2)云杉年轮指数与上一年10月平均气温、年蒸发量、年干燥度呈极显著负相关关系,年蒸发量是制约其径向年生长量的关键因子;(3)林窗模式疏伐措施显著促进了云杉个体径向生长,且生长释放效应在林窗边缘强于林内,优势木显著大于劣势木.综合说明通过小强度林窗疏伐措施,可有效改善林地环境,促进云杉生长,而优先疏伐被压的劣势木、最大限度保留优势木是优化小强度林窗疏伐方案的重要策略.
In this study, we selected Picea asperata with various growth status within the single spruce plantation in the western Sichuan to investigate their radial growth dynamics in various growth periods and the relationships with different climatic factors. We also applied the technique of thinning by mimicing gap formation, to explore the release effect of radial growth after the gap creation. The results showed that （1） the radial growth process was divided into two phases： the fast-growing period （1982-1993） and the slow-down-growing period （1994-2005）; in both phases the average annual radial growth increment of the dominant trees was significantly greater than that of the oppressed ones; （2） the tree-ring indices were related to climatic factors, including mean monthly temperature in previous October, annual evaporation and annual aridity index. This suggested that annual evaporation was the key factor to restricted radial growth; （3） the thinning by stimulating gap formation promoted the radial growth of spruce individuals. The release effect of growth at the gap fringe was stronger than that within stand canopy, and the effect of growth release was significantly stronger for dominant trees than the oppressed trees. We concluded that low intensity of thinning by mimicing gap formation can improve the forest environment quality and the individual ability in environmental resources utilization. Therefore, preferentially felling the oppressed trees and retaining the dominant trees within the single spruce plantation is suggested to be the key countermeasure to optimize the low intensity of gap model thinning and promote and retain growth release effect. Fig 5, Tab 4, Ref 50
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2013年第2期262-271,共10页
Chinese Journal of Applied and Environmental Biology
基金
中国科学院战略性先导科技专项子课题(X DA 0 5 0 7 0 3 0 6)
“十二五”国家科技支撑计划课题(2011BAC09B04-02)~~
关键词
人工纯林
云杉
径向生长过程
气候影响
林窗疏伐
生长释放
single tree species plantation
Picea asperata
radial growth process
climate influence
gap model thinning
growth release effect
