油松人工林林窗对幼苗天然更新的影响  

Effects of gap size on seedling natural regeneration in artificial Pinus tabulaeformis plantation

作　　者：韩文娟[1] 袁晓青[2] 张文辉[1] 

机构地区：[1]西北农林科技大学西部环境与生态教育部重点实验室,陕西杨凌712100 [2]延安市黄龙山林业局,陕西黄龙715700

出　　处：《应用生态学报》2012年第11期2940-2948,共9页Chinese Journal of Applied Ecology

基　　金："十二五"国家科技支撑计划项目(2012BAD22B0302);中国科学院战略性先导科技专项(XDA05060300);林业公益性行业科研专项(201004011)资助

摘　　要：为了阐明油松人工林间伐产生的林窗对幼苗天然更新的影响,通过典型样地调查,对不同生境的生态因子,以及1～10年生油松幼苗的年龄结构、高度、基径、针叶长及根、茎、叶生物量进行了调查,并对影响幼苗更新数量的环境因子进行通径分析.结果表明:阴坡与阳坡不同大小林窗下的生态因子存在明显差异.林下缺少3年生以上的幼苗,小林窗下缺少7年生以上的幼苗,大林窗下5、6年生幼苗较少.1～10年生油松幼苗可分为1～3年生、4～7年生和8～10年生3个阶段,1～3年生幼苗的存活是种群能否成功更新的关键.幼苗生长总体表现为阴坡大林窗>阳坡大林窗>阳坡小林窗>阴坡小林窗>阳坡林下>阴坡林下.通径分析表明,光照强度对各个阶段的幼苗数量起积极的决定作用,灌木层盖度对4～7年生及8～10年生幼苗数量均起积极的决定作用,腐殖质干质量对4～7年生幼苗数量起消极作用,但对8～10年生幼苗数量起积极作用.在油松人工林经营中,应进行高强度的间伐,同时清理林下灌木,为油松种群可持续发育提供条件.To clarify the effects of gap size created by thinning on the seedling natural regeneration in artificial Pinus tabulaeformis plantation, a plot investigation was eonducted to study the ecological factors and the age structure, height, diameter, length of needles, and dry biomass of roots, stems, and needles of 1-10 year-old seedlings in different habitats, and a path analysis was made on the environmental factors affecting the seedling regeneration. Obvious differences were observed in the ecological factors in different size gaps and slope aspects. There lacked of above 3 year-old seed- lings in understory and of above 7 year-old seedlings in small gap, and the seedlings of 5 and 6 year-old were lesser in big gap. The 1-10 year-old seedlings could be divided into 3 development phases, i. e. , 1-3 year-old, 4-7 year-old, and 8-10 year-old seedlings, among which, 1-3 year- old seedlings were critical for the establishment and growth of the population. The growth situation of the seedlings in different habitats was in order of big gap in shady slope 〉 big gap in sunny slope 〉 small gap in sunny slope 〉 small gap in shady slope 〉 understory in sunny slope 〉 under- story in shady slope. Path analysis showed light intensity had decisive positive effects on the seed- ling number of different development phases, shrub coverage had decisive negative effects on the seedling number of 4-7 year-old and 8-10 year-old phases, whereas humus dry mass had negative effects on the seedling number of 4-7 year-old but positive effects on the seedling number of 8-10 year-old. It was suggested that in the management of artificial P. tabulaeformis plantation, relative- ly high intensity thinning combined with shrub cleating should be adopted to provide favorable con- ditions for the sustainable development of P. tabulaeformis population.

关 键 词：油松 林窗大小 幼苗更新 通径分析 

分 类 号：S791.254[农业科学—林木遗传育种]