采伐干扰对大兴安岭落叶松-苔草沼泽植被碳储量的影响  

Effects of selective cutting on vegetation carbon storage of boreal Larix gmelinii-Carex schmidtii forested wetlands in Daxing'anling,China

作　　者：牟长城[1] 卢慧翠[1] 包旭[1] 王彪[1] 崔巍[1] 

机构地区：[1]东北林业大学生态研究中心,哈尔滨150040

出　　处：《生态学报》2013年第17期5286-5298,共13页Acta Ecologica Sinica

基　　金：国家"十二五"农村领域科技计划课题森林湿地生态系统功能恢复及优化技术研究与示范(2011BAD08B02-04)

摘　　要：运用采伐干扰试验与树干解析法,对比分析了大兴安岭不同采伐强度(未采伐———对照、轻度择伐———25%、中度择伐———35%、强度择伐———50%)下落叶松-苔草沼泽的植被生物量、碳含量、碳储量、净初级生产力及年净固碳量的变化,揭示采伐干扰(5a后)对落叶松-苔草沼泽植被碳储量及固碳能力的影响规律。结果表明:①不同采伐强度样地植被生物量为(135.03±7.72)—(204.71±1.71)t/hm2,择伐使其降低了8.7%—34.0%(P<0.05),且呈现出随择伐强度增大而递减的变化规律;②择伐使群落建群种兴安落叶松和白桦(两树种各组分碳含量为(439.05±9.70)—(508.41±27.09)g/kg的树干和树叶碳含量降低了4.1%—11.7%(P<0.05),轻度和强度择伐使灌木层(444.87±5.40)—(472.52±9.44)g/kg与凋落物层(433.64±16.23)—(468.82±21.27)g/kg的碳含量降低了3.8%—5.9%和6.0%—7.5%(P<0.05),但择伐对草本层碳含量(399.34±83.65)—(419.20±23.75)g/kg无显著影响;③不同采伐强度样地植被碳储量为(61.16±0.67)—(99.61±1.47)t·C/hm2,择伐使其降低了15.5%—38.6%(P<0.05),且呈现随择伐强度增大而递减的变化规律;④不同采伐强度样地植被净初级生产力与年净固碳量在(6.48±0.28)—(11.87±0.92)t·hm-2·a-1和(3.52±0.21)—(6.29±0.92)t·C·hm-2·a-1之间,轻度和中度择伐使两者提高了69.1%—83.2%和52.0%—78.7%(P<0.05)。因此,轻度择伐和中度择伐能够提高落叶松-苔草沼泽净初级生产力与碳吸纳能力。Forested wetlands are recognized as long-term terrestrial carbon （C） sinks, so they are very important in global C accounting. Harvest disturbance plays an important role in forested wetland ecosystems, since harvest can turn wetlands into a C source if soil respiration is stimulated more than photosynthesis. Daxing＇anling supports the main area of Chinese forested wetlands; however, the effects of harvesting on vegetative C storage and C sequestration in these wetlands are still poorly understood. The aim of this study was to evaluate changes in biomass, C concentration, C storage, net primary productivity and C sequestration under four harvesting intensities （0. 0%-an unharvested control, and 25%-low, 35%- moderate and 50%-high intensity selective cutting） 5 years after harvest conducted in Larix gmelinii-Carex schmidtii forested wetlands in the Daxing＇anling, northeast China. The study used experimental cutting and sample tree analysis methods to reveal the influence of selective cutting on wetland C sinks and provide a theoretical basis for sustainable wetland management. The main results follow： （ 1 ） Total vegetation biomass varied from （ 135.03±7.72 ） to （204.71 ± 1.71 ） t/hm2 at the various selective cutting sites and decreased significantly by 8.7%--34.0% as harvest intensity increased when comparing the three intensities of selective cutting （ P 〈 0. 05 ）. The decrease in total vegetation biomass mainly resulted from significant reductions of tree biomass, which comprise the dominant component （91.5%--96.0%） of this forested wetland type, although selective cutting could increase the understory biomass and reduce the litter biomass, both of which had only limited impacts on total vegetation biomass. （2） The C concentration of trees such as Larix gmelinii and Betula platyphylla ranged from （439.05±9.70 ） to （508.41 ± 27.09 ） g/kg; selective cutting resulted in a significant decrease in the root and leaf C concentrations by 4.1%--11.7% （P〈0. 05 ）.

关 键 词：大兴安岭 落叶松-苔草沼泽 生物量 碳储量 净初级生产力 采伐干扰 

分 类 号：S718.5[农业科学—林学]