| 摘要: |
| 【目的】探索不同间伐强度对阴坡、阳坡栓皮栎林木生长及干形的影响，为栓皮栎林的合理抚育间伐和经营提供依据。【方法】以秦岭南坡商洛地区阴坡、阳坡生长的栓皮栎次生纯林为研究对象，设置不同间伐强度（弱度、中度、强度间伐分别保留郁闭度为0.8，0.7和0.6）和对照（未间伐）样地各3块，每块样地面积20 m×20 m，于抚育间伐7年后对不同间伐强度下林木的生长、干形进行调查比较。【结果】阴、阳坡两种生境条件下，栓皮栎胸径、冠幅、单株胸高断面积、单株材积现存量均与间伐强度成正相关关系，间伐7年后林分胸高断面积、蓄积均下降，间伐强度对树高的影响不显著；两种坡向的林木胸径、树高、冠幅年均生长率均表现为冠幅年均生长率>胸径年均生长率>树高年均生长率；间伐后，两种坡向的林木平均通直度均提高，阴、阳坡林木平均通直度分别在中度、弱度间伐时最高，高径比、活枝下高有所降低，而栓皮栎林平均分杈率出现先下降后升高的趋势，阴坡的平均分杈率小于阳坡。【结论】间伐强度对不同坡向栓皮栎林木生长、干形的影响存在差异，强度间伐（保留郁闭度0.6）对两种坡向林木生长的促进效果最好； 弱度间伐（保留郁闭度0.8）较利于阳坡培育优质干形，而中度间伐（保留郁闭度0.7）较利于阴坡培育优质干形；对林分进行抚育间伐时，应考虑培育目标以及林木的生境条件，以便在更好地促进林木生长的同时获得更多的经济效益。 |
| 关键词: 栓皮栎 间伐强度 生境 林木生长 干形 |
| DOI： |
| 分类号: |
| 基金项目:陕西省科技统筹创新工程计划项目（2014KTCL02-04） |
|
| Effect of thinning intensity on growth and stem-form of Quercus variabilis in shady and sunny slopes |
|
YU Bi-yun,ZHANG Wen-hui
|
| Abstract: |
| 【Objective】The study explored the effect of different thinning intensities on growth and stem-form of Quercus variabilis in shady and sunny slopes to provide reference for proper thinning and management.【Method】The natural secondary Q.variabilis pure forest in shady and sunny slops in Shangluo,south Qinling Mountains was investigated with different thinning intensities (light thinning,medium thinning and heavy thinning with canopy densities of 0.8,0.7 and 0.6,respectively) and control group (un-thinned).Each case had 3 pieces and each sample plot was 20 m×20 m in area.After 7 years,the growth and stem-form of Q.variabilis were compared.【Result】Diameter at breast height (DBH),crown area,basal area at breast height and existing volume of single tree in both shady and sunny slopes were positively related to thinning intensity.Total basal area at breast height and crowing stock declined after thinning,while the influence of thinning intensity on tree height was not significant.The average annual growth rates of DBH,height and crown area in both habitats were in the same order of crown area>DBH>height.After thinning,tree average stem straightness in shady and sunny slopes was improved,and reached the highest level at medium thinning and light thinning,respectively.The height-diameter ratio and height under living branch declined,and the branching rate increased after initial decrease.The average branching rate of shady slope was less than that of sunny slope.【Conclusion】The effect of different thinning intensities on growth and stem form of Q.variabilis forest of different slope was different.Heavy thinning (canopy density 0.6) was conductive to the growth of forests in both shady and sunny slopes.Light thinning (canopy density 0.8) was more conductive to cultivate high-quality stem-form for sunny slope,while the medium thinning (canopy density 0.7) was good for shady slope forest to cultivate high quality stem-form.Therefore,to accelerate the tree growth and get more economic benefits,the purpose of thinning and forest habitat conditions should be taken into account. |
| Key words: Quercus variabilis thinning intensity slope growth stem form |
