抚育间伐强度对油松人工林群落和碳储量的影响

Effects of Different Tending Intensities on Community and Carbon Storage of Pinus Tabulaeformis Plantation

抚育间伐是人工林近自然经营的重要方式,以子午岭林区15年林龄的油松人工林为对象,以3000株/hm^(2)作为对照,设置3个保留密度,分别为1000株/hm^(2)(强度)、1600株/hm^(2)(中度)、2200株/hm^(2)(轻度),研究了不同抚育间伐强度对油松人工林群落、土壤性质和碳储量的影响。研究结果表明:油松胸径、树高、冠幅和单株材积随着间伐强度的增加逐渐增加,而油松种群林分蓄积量却以中度间伐处理达到最大值。林下结构多样性、灌木盖度和草本盖度均随着间伐强度的增加而增加,油松种群结构中乔木和草本的丰富度指数、集中性指数和多样性指数均随着间伐强度增加呈逐渐增加趋势,而灌木物种的丰富度指数、集中性指数和多样性指数却以中度间伐处理效果最佳。不同抚育间伐强度间的土壤容重差异不显著,土壤有机碳的含量、碳氮比随着间伐强度的增加而逐渐降低。油松人工林生态系统碳储量随着间伐强度的增加逐渐降低,并以乔木和土壤对油松人工林生态系统中贡献值最大。因此,中度间伐(1600株/hm^(2))条件下,不仅有利于促进油松人工林的生长,且能显著增加林下结构多样性和生态系统碳储量,可用于油松抚育管理。

Tending thinning is an important way to manage plantations near nature.Taking the 15-years-old Pinus tabulaeformis plantation in Ziwuling forest area as the object,with 3000 plants/hm^(2) as the control,3 retention densities were set,was 1000 plants/hm^(2).(intensity),1600 plants/hm^(2)(moderate),2200 plants/hm^(2)(mild),the effects of different thinning intensities on the community,soil properties and carbon storage of Pinus tabulaeformis plantation were studied.The results showed that:(1)Diameter at breast height,tree height,crown width and volume per plant of Pinus tabulaeformis increased gradually with the increase of thinning intensity.(2)Understory structural diversity,shrub cover and herb cover all increased with the increase of thinning intensity.The intensity increased gradually,while the richness index,concentration index and diversity index of shrub species decreased first and then increased with the increase of thinning intensity.(3)There was no significant difference in soil bulk density among different thinning intensities,and soil organic carbon content and carbon-nitrogen ratio gradually decreased with the increase of thinning intensities.(4)The carbon storage in the P.tabulaeformis plantation ecosystem decreased gradually with the increase of thinning intensity,and the tree and soil contributed the most to the P.tabulaeformis plantation ecosystem.Therefore,under the condition of moderate thinning(1600 plants/hm^(2)),it is not only beneficial to promote the growth of Pinus tabulaeformis plantation,but also can significantly increase the structural diversity and ecosystem carbon storage under the forest.It can be used for tending Pinus tabulaeformis manage.