抚育间伐对寒温带兴安落叶松天然林径级分布和固碳速率的影响

Effects of Tending Thinning on Diameter Class Distribution and Carbon Sequestration Rate of Natural Forest of Larix gmelinii in Cold Temperate Zone

抚育间伐是有效的营林措施,确定科学合理间伐强度对实现森林可持续经营具有重要作用。以2012年进行不同抚育间伐强度(10%、20%、30%、40%)措施后的兴安落叶松(Larix gemlinii)天然林为研究对象,分析了恢复5 a、10 a后不同抚育间伐强度样地内的林木径级分布、碳密度及固碳速率的变化。结果表明:随着抚育间伐强度的增大和恢复年份的增加,兴安落叶松天然林中、大径级的林木频数逐步增加,小径级林木频数降低,由左偏正态分布逐渐右移;各间伐样地中,兴安落叶松天然林碳密度随着抚育间伐强度增大呈现间伐初期先减小,5 a、10 a后增大的趋势,各组分碳密度分配均呈树干>树根>树皮>树枝>树叶;兴安落叶松天然林固碳速率随着抚育间伐强度的增大而增大,抚育间伐强度40%样地内的固碳速率最大。

Tending thinning is an effective measure of forest management,and determining scientific and reasonable thinning intensity plays an important role in achieving sustainable forest management.Taking the natural forest of Larix gmelinii after different thinning intensities(10%,20%,30%,40%)in 2012 as the research object,the changes of tree diameter distribution,carbon density and carbon sequestration rate in different tending thinning intensity plots after 5 years and 10 years of restoration were analyzed.The results showed that with the increase of thinning intensity and recovery year,the forest frequency of middle and high diameter trees in natural forest of Larix gmelinii gradually increased,the one of small diameter trees decreased,and the left skew normal distribution gradually shifted to the right.In each thinning plot,the carbon density of natural forest of Larix gmelinii decreased first with the increase of thinning intensity,and then increased after 5 years and 10 years.The carbon density distribution of each component was trunk>root>bark>branch>leaf.The carbon sequestration rate of natural forest of Larix gmelinii increased with the increase of thinning intensity,and the carbon sequestration rate in the 40%thinning intensity plot was the largest.