【作者】 任治忠；

【导师】 宁平；

【作者基本信息】 昆明理工大学 ， 环境工程， 2013， 博士

【摘要】 在全球气候变化的背景下,森林作为最重要的陆地生态系统,其碳库功能受到越来越多的重视。经营良好的人工林是不但是重要的碳库(Carbon pool),更是重要的碳汇(Carbon sink),关于生物量和碳储量的系统研究对于监测和评估人工林碳汇功能、研究开发碳汇造林技术具有重要的科学和技术意义。西南桦是云南重要的人工林树种和乡土树种,也是当地重要的亚热带植被类型。为了降低西南桦人工林碳储量估算的不确定性,并为开展西南桦碳汇造林提供技术支持,本研究在西南桦集中分布区内的云南2个州市,使用生物量收获法开展了西南桦中幼龄人工林样地调查,基于实测数据,计算了西南桦人工林的生物量、碳储量和关键的碳计量参数；分析了重要参数的空间分配规律和时间动态规律；在此基础上,对西南桦人工林的碳储量计量与监测技术进行了探讨。研究结果表明：(1)关于生物量积累。西南桦人工林的生物量积累,在中幼稚龄期服从逻辑斯蒂增长模型。和各林分层和单株个体的生物量积累呈现明显的规律。林龄(3-20)a生单株的生物量约为(0.92～193.61)kg,且可以用逻辑斯蒂、二次曲线或幂函数较好拟合其生物量积累规律。林龄(3-20)a林分的生物量约为(10.44-224.63)t.hm-2,灌木层生物量、乔木层生物量是林龄的一次函数；草本层生物量随林龄增长而呈现明显的减少；林分生物量、乔木层生物量和林分地上生物量随林龄增加呈逻辑斯蒂增长。(2)关于生产力变化。西南桦人工林乔木层的生产力随林龄增长的变化服从呈逻辑斯蒂模型,灌木层的生产力则服从s型曲线,草本层的生产力服从幂函数减小。西南桦中幼龄人工林的生产力总体上较高,且林分生产力的高低和结构比例在不同生长阶段都有变化。3-20a生西南桦人工林林分的生产力为(7.57±2.12)t.hm-2.a-1,乔木层、灌木层和草本层的生产力分别为(7.06±2.30) t.hm-2.a-1(0.27±0.27)t.hm-2.a-1和(0.23±0.21)t.hm-2.a-1。(3)关键参数率定方面。西南桦中幼龄人工林的生物量碳计量因子BCEF、BEF和R值都低于国际政府间气候变化理事会给出的的默认数值,且两者数值上的差别较大。在西南桦人工林固碳量估算中使用反映本地气候、地质等特点的实测样本率定出的关键参数将有助于提高固碳量计算的可靠性和本土化。西南桦中幼龄人工林生物量转化与扩展因子(BCEF)的平均值为0.5018Mg m-3,低于国际政府间气候变化理事会给出的的默认数值,且是林龄的极明显的负相关函数。西南桦中幼人工林生物量扩展因子(BEF)的均值为1.3562,低于国际政府间气候变化理事会给出的的默认数值,与是林龄的极明显的负相关函数。西南桦中幼人工林的根茎比(R)均值为0.1508,低于国际政府间气候变化理事会给出的的默认数值,且是林龄的极明显的负相关函数。(4)关于含碳率。西南桦中幼龄人工林林木的含碳率低于通用默认参数(50%),主要器官含碳率随林龄增长呈增加的趋势,林木不同构件间的含碳率不各相同但数值差距不大。其单株的全株含碳率,结合生物量权重值测算为48.33%。主干的平均含碳率48.08%,且主干含碳率略低于其他构件的含碳率,其它构件的含碳率依次为树皮(49.70%),叶(49.47%),根(48.50%),枝(48.27%)。(5)关于木材密度。西南桦人工林木材基本密度平均值在(0.341-0.651)g/cm3之间,从髓心至树皮呈逐渐增大的趋势,到第11年增至最大。西南桦人工林木材基本密度与树木生长年正相关,木材基本密度与生长轮林龄可用对数函数较好的拟合。西南桦人工林树干全株基本密度第1年为0.391g/cm3,随后逐渐增大,第13年树干全株基本密度为0.567g/cm3,随着树龄的增大,树干全株基本密度增大趋势逐渐减小,树干全株基本密度与林龄可用对数函数较好的拟合。(6)碳密度和固碳能力方面。西南桦中幼龄人工林具有较强的固碳能力功能,年均固碳量和生物量碳密度均较高。其年均固碳量和生物量碳密度较好地服从相关模型。(3-5)a、(6-8)a、(9-11)a、(12-14)a和(17-20)a林龄的西南桦人工林的生物量碳密度分别为(11.92±10.28)、(21.07±7.29)、(35.72±7.76)、(51.75±5.64)和(90.89±23.78)t.hm-2。,乔木层、灌木层和林分的碳密度随林龄呈现显著增加,草本层的碳密度则呈现较弱的下降趋势。林分碳密度、乔木层碳密度、灌木层碳密度随林龄的变化用二次曲线拟合效果良好。林龄为(3-5)a、(6-8)a、(9-11)a、(12-14)a和(17-20)a的西南桦人工林的年均固碳量分别为(2.69±1.61)、(3.04±1.07)、(3.58±0.78)、(3.97±0.13)和(4.87±0.73)t.hm-2.a-1。乔木层和草本层年固碳量与林龄的关系以双曲线函数拟合效果较好,林分年固碳量与林龄关系以幂函数拟合效果较好。(7)本论文在具体研究的基础上,参照国家相关部门的技术指南,采用与国际政府间气候变化理事会等国际规则接轨的方法,建立了西南桦人工林固碳量计算的系列模型并率定了关键参数,提出了该树种的林地的固碳量计量和监测方法。在满足林龄、立地和特定的管理经营水平等适用条件的情况下,提出的碳汇计量模参数和模型可以使用与实际的政府工作和研究活动。通过对西南桦人工林生物量和碳储量的系统的研究和样地调查,获得了该特定树种和林种的生物量碳计量参数及其动态,总结了其碳储量的分配规律,拟合了西南桦人工林的固碳功能的动态变化模型,率定了成系列的关键参数,提出了西南桦人工林固碳量计算和监测的操作方法。研究可以为降低西南桦人工林生物量和固碳量估算提供方法学并减低估算的不确定性,可以丰富云南碳汇造林的理论研究和实践有助于降低西南桦人工林生物量和碳储量估算的不确定性。在研究基础上,初步提出了西南桦人工林固碳能力计量和监测的成套技术。更多还原

【Abstract】 Under the context of globale warming, forest as the most important terrestrial ecosystem, its function as a carbon reservoir is increasingly recognized. Well manag ed plantation is not only a reservoir, but also a carbon sink. Studies on the biomas s and carbon stock of a plantation will be useful both for carbon sequestration pote ntial assessment and for caybon offsetting oriented silviculture technology developme nt. Betula alnoides is one of the most important species widely used for afforestatio n in Yunnan. To reduce uncertainty on biomass carbon estimation and generate tech nical tools for carbon accounting and monitoring for the plantation, a biomass surve y was conducted in two prefectures withing its central distribution areas in Yunnan, using harvesting method and allometric equations jointly. Based on data gathered fr om the survey, biomass density, carbon density and carbon accounting parameters fo r the plantation were calculated and their spatial distribution patterns and dynamics were analyzed respectively. Then technical issues regarding carbon accounting and m onitoring for Simao pine plantation were disscussed with feference to the foundings from this study. The results showed that:During the periods of young and middle age, with the increase on stand age, biomass of the plantation accumulated rapidly, ratios of different layers over the wh ole stand both for biomass and productivity varied significantly.Biomass density for t he plantation of Betula alnoides with ages of3-20a was in a range of10.44-224.63t.hm-2. Of which, arbor layer was determined as3.47-208.13t.hm-2, shrub layer determined as0.26-10.16t.hm-2, and grass layer determined as0.65-3.88t.hm-2. Significant linear correlations were found between the biomass density and the stand age for the arbor layer and shrub layer, and biomass density of grass layer was ne gatively related to its age. Logistic models developed by this study to relate biomas s density with age (variable)gave satisfied estimates for the stand, arbor layer and above-groud layer. Productivities of the plantations aged3-20for the stand, arbor layer, shrub layer and grass layer were7.57±2.30t.hm-2.a-1,7.06±2.30t.hm-2.a-10.27±0.27t.hm-2.a-1and0.23±0.21t.hm-2.a-1respectively. With the increase on age, productivity for the arbor layer increased remarkably following a logistic model, w hile the productivity for shrub layer changed following an S curve function and gra ss layer declined exponentially.Significent differences were found among biomass conversion and expansion fa ctor (BCEF), biomass expansion factor (BEF), and root-shoot ratio (R) compaired wi th the IPCC defaut values.Mean BCEF for Betula alnoides plantation was0.5018M g m-3(n=13,95%confidence interval=0.3419-0.6617), lower than the IPCC default value. BCEF for Betula alnoides plantation was negatively related to mean stand height (H), mean diameter at breast level (D),stand growing stock (V) and st and age(A)(P<0.05). And BCEF for the plantation was positatively related to st and density (N)(P<0.01). Regression equations developed for relating BCEF wit h stand factors gave satisfied estimates. Mean BEF for Betula alnoides plantation w as1.3562(n=13,95%confidence interval=0.1159～0.1857), lower than the IP CC default value. BEF was negatively related to D、H、V and A (P<0.01) and could be simulated successfully. Mean R for Pinus kesiya var. langbianensis plant ation was0.1508(n=13,95%confidence interval=0.1159～0.1857), lower tha n the IPCC default value. R was negatively related to D,H,V,A (P<0.01) and N (P<0.05)..Carbon content for Betula alnoides was lower than the commonly used default value (50%).Carbon content increased with the increase on stand age. Significent di fferences were found among different organs of the plant. The mean whole tree car bon content of Pinus Kesiya Var. langbianensis was calculated.as48.33%based on the dry biomass percentages of different organs and their respective carbon contents. The carbon content of main stem was48.08%,a little bit lower than that of bar k(49.70%, leaf (49.47%), roots (48.50) and branch(48.27%).The mean basic wood density of Betula alnoides was0.341-0.651g/cm3. It i ncreased outward from the heart to bark and reached its maximum at the age of11years. It was positively related to the age, and the basic wood density was logarith mically increased with the age of growth ring. The whole tree basic density of1year old Betula alnoides was0.391g/cm3, then increased logarithmically with age a nd reached0.567g/cm3at the13th year.Young and middled aged planation of simao pine had relatively high carbon d ensity, showing very strong carbon sequestration capacity.Biomass carbon density for the plantations of age3-5a,6-8a,9-11a,12-14a and17-20a were (11.92±10.28)、(21.07±7.29)、(35.72±7.76)、(51.75±5.64) and (90.89±23.78) t.hm-2respectiv ely. With the increase on stand age, carbon densities for arbor,shrub and stand layer were increased significantly, while that for grass layers decreased slightly. Relation s between carbon density and stand age for stand, arbor and shrub layer could be f itted by a curve of second order..Annual rate of carbon sequestration for the pla ntations of3～5a,6～8a,9～11a,12～14a and17～20a were (2.69±1.61),(3.04±1.07),(3.58±0.78),(3.97±0.13) and (4.87±0.73) t.hm-2.a-1respectively. T he rates for whole stand and arbor layer were both positively related to stand age (P<0.01) and that for grass layer was negatively related to stand age (P>0.05). The rate for shrub layer was negatively related to age but not statistically significant. M oreover, there was a typical power function relation between annual rate and age fo r whole stand.Results from this study could be used for carbon accounting and monitoring f or Betula alnoides plantation carbon offseting projects. Since the definitions and res earch procedures of this study were in line with relevant guidelines by IPCC and th e State Forestry Administration, results gained could be used directly for carbon acc ounting and monitoring for local carbon mitigating projects. However, site condition, stand age and management practice need to be fully taken into consideration when applied.To generalize, carbon accounting parameters gained from the study were speci es, forest type and site specific, thus the use of these parameters would be helpful i n reducing the uncertainty of carbon stock estimation. Secondly, methodologies for c arbon stock accounting and monitoring for the plantation of Betula alnoides was pro posed based on the results from the study. At last, the production, accumulation and allocation of biomass and carbon stock were studied, the results would be helpful for gaining a deep understanding on the dynamics of biomass and carbon stock acc umulation of Betula alnoides plantaion.The study could also provide valuable referen ce for carbon oriented silviculture technology development.更多还原