抚育间伐对红锥人工林生长和碳汇能力的影响

Effect of thinning on growth and carbon sink capacity of Castanopsis hystrix plantations

[目的]探讨不同抚育间伐方式对红锥人工林林分生长和碳汇能力的影响,为提高红锥林分的经营管理效率提供参考。[方法]以红锥人工林为研究对象,分别设置高强度抚育间伐、低强度抚育间伐以及未抚育间伐(CK)3个处理。间伐后1、2 a,对样地内植株进行每木检尺,测定林木生长特征,并比较红锥人工林林木碳密度及碳储量的变化特征。[结果]低强度抚育间伐处理下红锥树高增长量最大,达2.43 m,树冠以纵向生长为主;高强度抚育间伐处理下胸径增长量最大,为2.68 cm,树冠以横向生长为主;两种抚育间伐处理下的树高和胸径增长量均显著大于CK。高强度、低强度抚育间伐后红锥人工林蓄积量、林木碳密度以及碳储量均有所降低,但单株材积、林分蓄积量、林木碳密度及碳储量的增长率均显著大于CK,且以低强度抚育间伐处理最大,分别为129.32%、122.88%、122.88%及117.39%。间伐后2 a红锥人工林林木生长特征参数及碳汇特征参数均明显大于间伐后1 a。[结论]抚育间伐后红锥人工林林木生长和碳汇能力逐渐增强,并以低强度抚育间伐处理最为明显。因此,对红锥人工林进行营林管理可优先考虑低强度抚育间伐处理。

[Purpose]The aim of this study was to explore the effects of different thinning methods on the growth and carbon sequestration capacity of Castanopsis hystrix plantation,and to provide reference for improving the management efficiency of C.hystrix plantation.[Method]Three treatments were established for the C.hystrix plantations,including high-intensity thinning,low-intensity thinning,and a control group with no thinning(CK).One and two years post thinning,each tree was measured to assess growth characteristics in the plot,and changes in carbon density and stand carbon storage of the C.hystrix plantation were compared.[Result]Under low-intensity thinning treatment,the tree height exhibited the most significant increase,reaching 2.43 m,with crown growth primarily occurring in a longitudinal direction.Conversely,under high-intensity thinning treatment,the diameter at breast height(DBH)experienced the greatest increase of 2.68 cm,while crown development predominantly occurred in a lateral direction.The increase of enzyme height and DBH under two tending thinning treatments was significantly greater than CK.After high-and low-intensity thinning,the stand volume,carbon density,and carbon storage of C.hystrix plantations decreased,but the growth rates of individual volume,stand volume,carbon density,and carbon storage were significantly higher than those of CK,with the highest growth rates being 129.32%,122.88%,122.88%,and 117.39%for low-intensity thinning,respectively.The growth characteristics and carbon sink characteristics of 2-year post-thinning C.hystrix plantation were significantly higher than those of 1-year post-thinning plantation.[Conclusion]The growth and carbon sink capacity of C.hystrix plantations after thinning have a gradual increasing trend,and the low-intensity thinning treatment has the most obvious effect.Therefore,low-intensity thinning treatment should be prioritized for the management of C.hystrix plantations.