【作者】 魏书精；

【导师】 胡海清； 孙龙；

【作者基本信息】 东北林业大学 ， 森林防火， 2013， 博士

【摘要】 人类活动所引起的温室效应以及由此造成的以气候变暖为主要特征的气候变化和对全球生态环境的影响已受到国际社会的普遍关注,是全球性问题研究的热点。火干扰作为森林生态系统的重要干扰因子,剧烈地改变着森林生态系统的结构、功能、格局与过程,改变生态系统的碳分配格局与碳循环过程,影响生物地球化学循环,干扰生态系统的能量流动、物质循环与信息传递,是引起植被和土壤碳储量动态变化的重要原因,进而调控生态系统的碳收支,对区域乃至全球的碳循环与碳平衡产生重要影响。火干扰对森林生态系统碳循环产生的重要影响已引起人们的广泛关注。正确理解气候变化背景下火干扰与森林生态系统碳循环之间的逻辑循环关系,了解气候变暖背景下火干扰对森林生态系统碳循环的影响,对制定科学合理的林火管理策略和优化林火管理的路径、充分发挥林火管理措施在增加森林生态系统碳吸收汇,减少碳排放源中的碳效应,实现碳减排增汇效应,减缓气候变化速率等方面均有重要的意义。黑龙江省是我国森林资源大省,是重点林区,亦是森林火灾易发多发区,年均森林火灾面积居全国之首,开展该省森林火灾碳排放定量评价方法研究,改进森林火灾碳排放计量模型,科学测定森林火灾碳排放计量参数,合理计量森林火灾碳排放量,对了解火干扰在区域碳循环和碳平衡中的地位与作用具有重要意义。据此,以黑龙江省温带林和黑龙江省大兴安岭北方林为研究区域,以典型森林生态系统为研究对象,采用地理信息系统技术(GIS),通过大量野外火烧迹地调查与采样,结合室内控制环境实验以及野外实验,测定森林火灾碳排放的各种计量参数和4种主要含碳气体排放因子计量参数,在林分水平上,通过修正的森林火灾碳排放计量模型,对该省森林火灾碳排放量进行计量估算,采用排放因子法,对该省森林火灾4种主要含碳气体排放量进行计量估算,分析了森林火灾的时空分布格局及变化规律。通过分析森林火灾碳排放量和4种主要含碳气体排放量的研究结果,提出了科学合理的林火管理策略和优化林火管理的路径。主要结果如下：(1)系统地阐述了森林火灾碳排放定量评价方法。论述了野外火烧迹地调查与采样方法；室内控制环境实验及野外实验方法；森林火灾碳排放各种计量参数和4种主要含碳气体排放因子计量参数的测定方法；改进了森林火灾碳排放计量模型,使得森林火灾碳排放计量模型分别适用于黑龙江省温带林和黑龙江省大兴安岭北方林的碳排放计量：从林分水平上,阐明了森林火灾碳排放量的计量估算方法,采用排放因子法,论述了森林火灾4种主要含碳气体排放量的计量估算方法。(2)测定了森林火灾碳排放计量参数及主要含碳气体排放因子计量参数,并建立了计量参数数据库。分别测定了黑龙江省温带林和大兴安岭北方林森林火灾碳排放计量参数(各林型不同组分的单位面积森林可燃物载量、可燃物含碳率和燃烧效率)和4种主要含碳气体排放因子,在林分水平上对燃烧效率和排放因子进行了测定,测定了森林火灾土壤有机碳排放的计量参数,并建立了较为全面的森林火灾碳排放各计量参数及4种主要含碳气体排放因子计量参数数据库。(3)估算了大兴安岭北方林森林火灾碳排放量及单位面积碳排放量。通过实测的森林火灾碳排放各计量参数,根据大兴安岭不同林型,在林分水半上计量估算了1965—2010年46年间森林火灾碳排放量为3.12×107t,年均碳排放量为6.79×105t。分别计算了各林型单位面积森林火灾碳排放量：杜鹃-落叶松林11.79t/hm2、杜香-落叶松林7.53t/hm2、草类-落叶松林11.51t/hm2、偃松-落叶松林10.85t/hm2、白桦林5.55t/hm2、樟子松林4.01t/hm2、蒙古栎林12.67t/hm2、针叶林18.72t/hm2、阔叶林11.20t/hm2、针阔混交林3.06t/hm2。46年间森林火灾土壤有机碳排放量为2.20×107t,年均排放量为4.77×105t。分别计算了各林型单位面积森林火灾土壤有机碳排放量：杜鹃-落叶松林8.81t/hm2、杜香-落叶松林4.40t/hm2、草类-落叶松林6.65t/hm2、偃松-落叶松林7.97t/hm2、白桦林4.52t/hm2、樟子松林5.69t/hm2、蒙古栎林7.13t/hm2、针叶林8.58t/hm2、阔叶林4.64t/hm2、针阔混交林3.54t/hm2。(4)估算了大兴安岭北方林森林火灾4种含碳气体排放量及单位面积排放量。通过实测的森林火灾4种主要含碳气体的排放因子,根据大兴安岭不同林型,采用排放因子法计量估算了4种含碳气体排放量。46年间森林火灾含碳气体CO2、CO、CH4和非甲烷烃(NMHC)的排放量分别为9.76×107、9.51×106、5.46×105和2.14×105t,其年均排放量分别为2.12×106、2.07×105、1.19×104和4.65×103t。分别计算了单位面积4种主要含碳气体排放量：各林型CO2/CO、CH4和NMHC的排放量分别为：杜鹃-落叶松林36.09、4.18、0.22和0.07t/hm2；杜香-落叶松林23.94、2.35、0.10和0.05t/hm2：草类-落叶松林36.35、4.09、0.24和0.08t/hm2；偃松-落叶松林34.59、3.09、0.21和0.07t/hm2；白桦林17.48、1.35、0.07和0.04t/hm2；樟子松林12.30、1.18、0.13和0.03t/hrn2；蒙古栎林40.89、3.37、0.19和0.09t/hm2；针叶林58.43、3.66、0.27和0.14t/hm2；阔叶林36.36、2.34、0.11和0.08t/hm2；针阔混交林9.53、0.84、0.05和0.02t/hm2。(5)估算了黑龙江省温带林森林火灾碳排放量及单位面积碳排放量。通过实测的森林火灾碳排放计量参数,根据不同林型,在林分水平上计量估算了1953—-2012年60年间森林火灾碳排放量为5.88×107t,年均排放量为9.80×10st。分别计量了单位面积森林火灾碳排放量：阔叶红松林12.50t/hm2、落叶松林16.84t/hm2、白桦林20.07t/hm2、落叶松-白桦林12.99t/hm2、樟子松林22.25t/hm2、云冷杉林25.60t/hm2、杨桦林23.97t/hm2、硬阔林12.74t/hm2、蒙古栎林13.58t/hm2、针叶林29.75t/hm2、阔叶林26.42t/hm2、针阔混交林7.05t/hm2。60年间森林火灾土壤有机碳排放量为1.92×107t,年均排放量为3.20×105t。计量了单位面积森林火灾土壤有机碳排放量：阔叶红松林2.56t/hm2、落叶松林6.02t/hm2、白桦林5.77t/hm2、落叶松-白桦林2.73t/hm2、樟子松林6.99t/hm2、云冷杉林9.00t/hm2、杨桦林7.47t/hm2、硬阔林6.71t/hm2、蒙古栎林6.44t/hm2、针叶林7.70t/hm2、阔叶林6.22t/hm2、针阔混交林3.28t/hm2。(6)估算了黑龙江省温带林森林火灾4种含碳气体排放量及单位面积排放量。通过实测的森林火灾4种含碳气体的排放因子,根据不同林型,利用排放因子法计量估算了4种含碳气体排放量。含碳气体CO2、CO、CH4和NMHC的排放量分别为1.89×108、1.06×107、6.33×105和4.43×105t,其年均排放量分别为3.15×106、1.77×105、1.05×104和7.38×103t。分别计量了单位面积4种主要含碳气体排放量：各林型C02、CO、CH4和NMHC的排放量分别为：阔叶红松林39.07、2.64、0.14和0.09t/hm2；落叶松林52.87、3.39、0.18和0.13t/hm2；白桦林66.06、3.62、0.24和0.15t/hm2；落叶松-白桦林41.72、2.15、0.13和0.08t/hm2；樟子松林7.27、3.99、0.20和0.18t/hm2；云冷杉林85.55、3.72、0.25和0.20t/hm2；杨桦林76.56、4.46、0.27和0.20t/hm2；硬阔林41.30、2.10、0.15和0.11t/hm2；蒙古栎林43.93、2.54、0.15和0.11t/hm2；针叶林97.72、4.48、0.28和0.23t/hm2；阔叶林87.80、3.83、0.31和0.20t/hm2；针阔混交林21.49、1.45、0.06和0.05t/hm2。(7)提出了合理的林火管理策略和优化林火管理的路径。通过分别对黑龙江省大兴安岭北方林和黑龙江省温带林森林火灾碳排放各计量参数及4种主要含碳气体排放因子的测定结果进行分析,并结合森林火灾碳排放量及4种主要含碳气体排放量的计量结果可知,不同林型森林火灾碳排放计量参数存在较大差异,尤其是燃烧效率和排放因子,从而导致森林火灾碳排放量以及含碳气体排放量存在较大的差异,对此提出了相应的林火管理策略和优化林火管理的路径,并提出了减缓气候变暖,增加森林碳吸收汇的森林碳汇管理措施。(8)黑龙江省年均的碳排放对区域的碳循环与碳平衡产生重要影响。大兴安岭北方林森林火灾年均碳排放量约占全国年均森林火灾碳排放量的6.00%。土壤有机碳年均排放量约占全国年均森林火灾碳排放量的4.22%。4种主要含碳气体CO2、CO、CH4和NMHC的年均排放量分别占全国年均森林火灾各含碳气体排放量的5.22%、7.63%、10.60%和4.12%,CO2、CO和CH4的排放量分别约占我国年均生物质燃烧各含碳气体排放量的0.76%、1.29%和2.20%。黑龙江省温带林森林火灾年均碳排放量约占全国年均森林火灾碳排放量的8.66%。土壤有机碳年均排放量约占全国年均森林火灾碳排放量的2.83%。4种主要含碳气体CO2、CO、CH4和NMHC的年均排放量分别约占全国年均森林火灾各含碳气体排放量的7.74%、6.52%、9.42%和6.53%,CO2、CO和CH4的排放量分别约占我国年均生物质燃烧各含碳气体排放量的1.12%、1.10%和1.95%。由以上研究可知黑龙江省年均的碳排放对区域的碳循环与碳平衡产生重要影响。为此,提出了优化森林碳汇管理,减少森林火灾碳排放的森林经营可持续管理策略。更多还原

【Abstract】 The greenhouse effect, which is caused by human activities, creates climate change, disrupts ecosystems and is causing increasing concern internationally. Forest fires, and the related disturbance, are a natural component of forest ecosystems. Forest fire, a main disturbance factor in forest ecosystems, is widely recognized as an essential natural process in those ecosystems. Many people have begun to realize that fires not only have physical effects but forest fires may increase in number and become more intense in response to future climatic change, which will influence the carbon cycle in forest ecosystems.Understanding the effect of fire disturbance and the changes it causes to a forest ecosystem’s carbon cycle under the background of climate warming is important in support of attempts to gain a correct understanding of the overall effects of climate warming. Scientists need to formulate reasonable and scientifically-based methods to measure these effects in support of developing a forest fire management strategy. Estimating and displaying forest fire carbon emissions will allow land managers to better manage and understand the vital significance of the forest ecosystem carbon cycle and the function of carbon balance within the ecosystem. Finally, we propose an effective and scientifically-based forest fire management strategy.This paper analyzes the carbon cycle in two typical forests:the boreal forest of Daxing’anling Mountains and the temperate forest of Heilongjiang Province, China. A large number of field studies and extensive sampling were combined with indoor controlled environment experiments and data analysis to determine forest fire carbon and carbonaceous gas emissions at the stand level. This was done using a model to estimate forest fire carbon emissions and to analyze factors affecting emissions. Forest fire carbon and carbonaceous gas emissions were estimated and analyzed for a Heilongjiang Province forest (Daxing’anling boreal forest and Heilongjiang Province temperate forest), including an analysis of the spatial and temporal patterns of forest fires and the climatological factors influencing changes in fire intensity and extent.An optimal path for forest fire management can be determined by combining scientific and reasonable forest fire management strategies with an analysis of carbon and carbonaceous gas emissions from forest fires. The main results follow.1) Forest fire carbon emissions are systematically and quantitatively evaluated. Several field investigation and sampling methods are discussed, including:indoor controlled environment experiments and experimental analysis methods, analysis of forest fire carbon and carbonaceous gas emissions using various methods to determine the parameters to be measured, modeling and measuring of forest fire carbon emissions, stand level analysis used to clarify forest fire carbon emissions estimates and factors affecting emissions, and discussion of the methods used to estimate and inventory forest fire carbonaceous gas emissions.2) A database of actual forest fire carbon emissions was created using the selected parameters. Carbon emissions parameters (per unit area of forest fuel loading, fuel carbon content and combustion efficiency) and the main emission factors were measured for the Daxing’anling boreal forest and Heilongjiang Province temperate forest allowing the establishment of a more comprehensive forest fire emission database.3) Total forest fire carbon emissions for forest fires in the Daxing’anling boreal forest during1965-2010(46years) were estimated to be3.12×107t, or an average of6.79×105t yr-1. Forest fire carbon emissions for various forest types were:Larix-Rhododendron forests,11.79t/hm2; Larix-Ledum forests,7.53t/hm2; Larix-grass forests,11.51t/hm2; Pinus pumila-Larix gmelinii forests,10.85t/hm2; Betula platyphylla forests,5.55t/hm2; Pinus sylvestris var. mongolica forests,4.01t/hm2; Quercus mongolica forests,12.67t/hm2; coniferous forests,18.72t/hm2; broad-leaved forests,11.20t/hm2; coniferous broad-leaved mixed forests,3.06t/hm2. The46-year soil organic carbon emissions from forest fires totaled2.20×107t.4) Levels of emissions of four major carbonaceous gases from forest fires were estimated for the Daxing’anling boreal forest. Forest fire carbonaceous gas [CO2, CO, CH4and non-methane hydrocarbons (NMHC)] emissions in the Daxing’anling boreal forest were estimated to be9.76×107t,9.51×106t,5.46×105t and2.14x105t, respectively, with an annual average of2.12×106t,2.07×105t,1.19×104t and4.65×103t, respectively. Emissions of the four major carbonaceous gases (CO2, CO, CH4, and NMHC, listed respectively below) calculated per unit area for each forest type were:Larix-Rhododendron forests,36.09,4.18,0.22and0.07t/hm2; Larix-Ledum forests,23.94,2.35,0.10and0.05t/hm2; Larix-grass forests,36.35,4.09,0.24and0.08t/hm2; P. pumila-L. gmelinii forests,34.59,3.09,0.21and0.07t/hm2; B. platyphylla forests,17.48,1.35,0.07and0.04t/hm2; P. sylvestris var. mongolica forests,12.30,1.18,0.13and0.03t/hm2; Q. mongolica forests,40.89,3.37,0.19and0.09t/hm2; coniferous forests,58.43,3.66,0.27and0.14t/hm2; broad-leaved forests,36.36,2.34,0.11and0.08t/hm2; coniferous broad-leaved mixed forests,9.53,0.84,0.05and0.02t/hm2.5) Total forest fire carbon emissions for Heilongjiang Province temperate forest during1953-2012(60years) were estimated to be5.88x107t, or an average of9.80×105t yr-1. Calculated forest fire carbon emissions per unit area for various forest types were:broad-leaved Pinus koraiensis forests,12.50t/hm2; L. gmelinii forests,16.84t/hm2; B. platyphylla forests,20.07t/hm2; B. platyphylla-L. gmelinii forests,12.99t/hm2; P. sylvestris var. mongolica forests,22.25t/hm2; Abies nephrolepis-Picea asperata forests,25.60t/hm2; B. platyphylla-Populus davidiana forests,23.97t/hm2; hardwood forests,12.74t/hm2; Q. mongolica forests, 13.58t/hm2; coniferous forests,29.75t/hm2; broad-leaved forests,26.42t/hm2; coniferous broad-leaved mixed forests,7.05t/hm2. The60-year soil organic carbon emissions from forest fires totaled1.92×107t and the average annual emissions were3.20x105t, accounting for2.83%of the national average annual forest fire carbon emissions.6) Levels of emissions of four major carbonaceous gases from forest fires were estimated for Heilongjiang Province temperate forest. Forest fire carbonaceous gas (CO2, CO, CH4and NMHC) emissions in Heilongjiang Province temperate forest were estimated to be1.89×108t,1.06×107t,6.33×105t and4.43×105t, respectively. Its average annual emissions were3.15×106t,1.77×105t,1.05×104t and7.38×103t, respectively. Emissions of the four major carbonaceous gases (CO2, CO, CH4, and NMHC, listed respectively below) calculated per unit area for each forest type were:broad-leaved Pinus koraiensis forests,39.07,2.64,0.14and0.09t/hm2; L. gmelinii forests,52.87,3.39,0.18and0.13t/hm2; B. platyphylla forests,66.06,3.62,0.24and0.15t/hm2; B. platyphylla-L. gmelinii forests,41.72,2.15,0.13and0.08t/hm2; P. sylvestris var. mongolica forests,7.27,3.99,0.20and0.18t/hm2; A. nephrolepis-P. asperata forests,85.55,3.72,0.25and0.20t/hm2; B. platyphylla-P. davidiana forests,76.56,4.46,0.27and0.20t/hm2; hardwood forests,41.30,2.10,0.15and0.11t/hm2; O. mongolica forests,43.93,2.54,0.15and the0.11t/hm2; coniferous forests,97.72,4.48,0.28and0.23t/hm2; broad-leaved forests,87.80,3.83,0.31and0.20t/hm2; coniferous broad-leaved mixed forests,21.49,1.45,0.06and0.05t/hm2.7) A corresponding forest fire management strategy and optimal path for forest fire management is outlined. During the analysis of carbon emissions from forest fires, we found that the forest fire carbon emissions varied widely for these two study areas; emissions were especially influenced by combustion efficiency and other factors influencing emissions. These factors need to be considered when developing a forest fire management strategy and optimal path for forest fire management.8) Changes in the average annual carbon emissions in Heilongjiang Province have an important impact on the carbon cycle and carbon balance in that area. Fires in the Daxing’anling boreal forest annually produce an average of about6.00%of the national average annual forest fire carbon emissions, and annual soil organic carbon emissions in this area account for about4.22%of the national average annual forest fire carbon emissions. Annual emissions of the four major carbonaceous gases (CO2, CO, CH4and NMHC) accounted for5.22,7.63,10.60and4.12%of the national average annual forest fire emissions of these gases, respectively or for0.76,1.29and2.20%of the national average annual biomass from carbonaceous gas emissions from burning, respectively. Annual emissions from forest fires in Heilongjiang Province temperate forest account for about8.66%of the national average annual forest fire carbon emissions, while annual soil organic carbon emissions in that area account for about2.83%of the national average annual forest fire carbon emissions. Annual emissions of the four main carbonaceous gases (CO2, CO, CH4and NMHC) accounted for7.74,6.52,9.42and6.53%of the national average annual forest fire emissions of carbonaceous gases, respectively, accounting for5.22,7.63,10.60and4.12%of the national average annual biomass from carbonaceous gas emissions from burning, respectively.更多还原