间伐对蒙古栎次生林生态系统碳储量的短期和长期影响

Short-term and Long-term Effects of Thinning on Carbon Storage of Quercus mongolica Secondary Forests

准确评估抚育间伐后林分碳储量的变化对提高林业碳汇功能具有重要意义。以伐后6a和23a蒙古栎次生林为研究对象,分析不同抚育间伐强度对林分碳储量及其组分分配的长、短期影响。结果表明:在短期(伐后6a)试验中,强度间伐乔木层碳储量低于对照12.6%,中度间伐略高于对照;在长期(伐后23a)试验中,各间伐强度乔木层碳储量与对照无明显差异。伐后森林恢复期的长短对林下植被碳储量的影响不同。在短期内,林下植被碳储量随间伐强度的增加而增大;而在长期内,各间伐强度林下植被碳储量无显著差异(p>0.05)。不同抚育间伐强度对枯落物层碳储量长期、短期均无显著影响(p>0.05),对土壤层碳储量的影响短期表现为强度间伐显著高于对照34.70%(p<0.05),中度间伐与对照无显著差异(p>0.05),长期表现为各间伐强度与对照均无显著差异。短期内强度、中度和对照样地生态系统碳储量分别为183.41,177.21,178.97t·hm^-2,强度间伐高于对照2.5%,中度间伐与对照相近。长期内不同间伐强度蒙古栎次生林生态系统碳储量均高于对照,分别高于对照3.2%, 5.8%和3.3%。由此可知,抚育间伐对蒙古栎次生林生态系统碳储量的影响受伐后森林恢复时间影响较大,短期内间伐对生态系统碳储量无显著影响,长期表现为间伐对生态系统碳储量的积累具有一定的促进作用。

Accurate assessment of carbon storage variance after thinning had important significance to increase carbon sequestration functions. Taking Quercus mongolica secondary forests 6 a and 23 a after thinning as research objects, short-term and long-term effects of different thinning intensity on forest stand carbon storage and ingredients allocation were analysed.Results showed: in short term(6 a after thinning)trial,carbon storage of arborous layer was 12.6% lower than that of the control in heavy thinning treatment, carbon storage of arborous layer was slightly higher than that of the control in moderate thinning treatment;In long term(23 a after thinning) trail, carbon storages of arborous layer in different thinning intensity treatments had no obvious difference compared with control. The period of forest convalescent had different effects on carbon storage of understory vegetation in short term, carbon storage of understorey vegetation increased with the increasing thinning intensity,carbon storage of understorey vegetation of different thinning intensity had no significant difference in long term(p>0.05). different thinning intensities had no significant effects on carbon storage of litter layer both in short term and in long term(p>0.05), short term effect of heavy thinning on carbon storage of soil layer was 34.70% higher than control(p>0.05), moderate thinning had no significant effects compared with control, different thinning intensities had no significant difference compared with control in long term. Carbon storage of ecosystem of heavy thinning, moderate thinning and control in short term was 183.41, 177.21, 178.97 t·hm^-2 respectively.Carbon storage of ecosystem of heavy thinning was 2.5% higher than the control, and carbon storage of ecosystem of moderate thinning was similar to the control. Carbon storage of Quercus mongolica secondary forest ecosystem of different thinning intensity was 3.2%, 5.8% and 3.3%high than the control in long term.it could been seen, effects of thinning on carbon storage of Quercus mongolica secondary forest ecosystem affected by forest convalescent, thinning had no significant effect on total carbon storage of the stand in short term, thinning accelerated the accumulation of the total carbon storage of the forest stand in long term.