秦岭南坡林窗大小对栓皮栎实生苗构型的影响  

Effects of forest gap size on the architecture of Quercus variablis seedlings on the south slope of Qinling Mountains,West China

作　　者：余碧云[1] 张文辉[1] 何婷[1] 尤健健[1] 李罡[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,陕西杨陵712100

出　　处：《应用生态学报》2014年第12期3399-3406,共8页Chinese Journal of Applied Ecology

基　　金："十二五"国家科技支撑计划项目(2012BAD22B0302)资助

摘　　要：以秦岭南坡栓皮栎天然次生林间伐后形成的不同大小林窗实生苗为材料,采用典型抽样法调查林窗大小对栓皮栎实生苗枝系构型、叶片特征及其垂直分布的影响.结果表明:林窗大小显著影响了栓皮栎实生苗的地径、树冠面积,林窗大小与地径呈显著正相关,与树冠面积呈显著负相关;林窗大小对实生苗苗高、冠长、树冠率均无显著影响;实生苗总体分枝率、逐步分枝率、枝径比均表现为大林窗>中林窗>小林窗>林下,不同林窗大小实生苗一级枝在垂直方向上主要分布于干的中、上部,直径较大的一级枝主要分布在中下部,一级枝倾角均随苗高的增高呈先增加后降低的趋势;随着林窗面积的增大,实生苗的叶长、叶宽和单叶面积逐渐下降,平均单株叶数、相对高度上的总叶数增加,叶长宽比在不同大小林窗下均保持稳定,相对叶数均在干的中上部分布较多,叶面积指数与相对叶总数的变化一致;中林窗实生苗地径与大林窗无显著差异,但苗高较高,利于栓皮栎种群更新及培育优质干材.在栓皮栎林经营管理过程中,需确定合适的间伐强度增加中林窗数量,促进栓皮栎实生苗更新以及培育优质干材.Typical sampling method was conducted to survey the effects of forest gap architecture, leaf characteristics and their vertical distribution of Quercus variablis size on branch seedlings from different size gaps in natural secondary Q. variablis thinning forest, on the south slope of Qinling Mountains. The results showed that gap size significantly affected the diameter, crown area of Q. variablis seedlings. The gap size positively correlated with crown area, while it had no significant impact on seedling diameter and negatively correlated with height, crown length and crown rates. The overall bifurcation ratio, stepwise bifurcation ratio, and ratio of branch diameter followed as large gap 〉 middle gap 〉 small gap 〉 understory. The vertical distribution of first-order branches under different size gaps mainly concentrated at the middle and upper part of trunk, larger diameter first-order branches were mainly distributed at the lower part of trunk, and the angle of first-order branch increased at first and then declined with the increasing seedling height. With the increasing forest gap size, the leaf length, leaf width and average leaf area of seedlings all gradually declined, while the average leaf number per plant and relative total leaf number increased, the leaf length- width ratio kept stable, the relative leaf number was mainly distributed at the middle and upper parts of trunk, the changes of leaf area index was consistent with the change of the relative total number of leaves. There was no significant difference between the diameters of middle gap and large gap seedlings, but the diameter of middle gap seedlings was higher than that of large gap, sugges- ting the middle gap would benefit the seedlings regeneration and high-quality timber cultivation. To promote the regeneration of Q. variabilis seedlings, and to cultivate high-quality timber, appropriate thinning should be taken to increase the number of middle gaps in the management of Q. variabilis forest.

关 键 词：栓皮栎 林窗 实生苗 构型 

分 类 号：S792.18[农业科学—林木遗传育种]