【作者】 石军南；

【导师】 田大伦；

【作者基本信息】 中南林业科技大学 ， 生态学， 2010， 博士

【副题名】以广西八步区为例

【摘要】 由于人类工业化发展,以CO2等温室气体过度排放引起的全球气候变化,已经威胁到人类的生存和发展。气候变化的预测要求准确地估计陆地生态系统碳吸收量及其变化。森林是陆地生态系统的主体,森林生态系统在全球碳循环中扮演着重要角色。森林生态系统的碳贮量不仅是反映森林生态系统基本特征的重要指标,也是评价森林生态系统生产潜力和森林结构与功能的理论基础。我国幅员辽阔,植被类型多样,森林生态系统复杂,区域性生物量和碳贮量估测是一个难点。根据区域的自然环境选择适合的研究方法,得出不同区域不同森林类型的碳贮量和碳密度,以估测全国或全球森林生态系统碳汇功能显得极为重要。寻找和森林资源二类清查兼容的生物量估测方法,利用森林资源二类调查资料进行区域性森林植被生物量和碳贮量估测,具有重要的实践意义。本文采用生态学原理、数理统计学方法和地理信息系统空间分析技术,利用广西八步区最新森林资源二类调查资料,应用相对比较成熟的生物量扩展因子法估算了研究区森林植被生物量和碳贮量,并对森林结构碳贮量特征和空间分布特征进行了分析,采用方差分析方法对森林植被碳贮量的生态环境影响进行了分析。研究过程中,针对森林资源二类调查技术规程中的土地类型结合生物量估算要求和生物量估测模型特点,进行了生物量估测森林植被类型划分,对所有植被类型生物量计算方法做了准确而全面的阐述,在森林资源调查小班数据库基础上建立了森林植被生物量和碳贮量小班数据库,并使用地理信息系统软件编制了森林植被生物量和碳密度分布图,采用矢量图形数据格网化方法编制了森林植被生物量和碳密度空间变化图,对1999年和2009年调查期间的碳贮量时空变化进行了研究。主要研究结果为：1、八步区森林植被生物量总量为11712180.2t,其中乔木层及灌木层合计为8283011.3t,林下层为1282786.8t,凋落物生物量为2146382.1t。2、全区森林植被总碳贮量为5942324.2t,其中林地总碳贮量为5849565.3t,而非林地的四旁树总的碳贮量为92758.9 t。林地中的乔木林的碳贮量所占比重最大,其碳贮量占八步区总碳贮量的88.07%。全区总平均碳密度为17.65323t/hm2,林地碳密度为22.05t/hm2,森林碳密度为23.69t/hm2。3、森林植被碳贮量的分布格局和特征：在地域上森林植被碳贮量随人口密度减少而增加；碳贮量与土地利用类型有关,各土地类型中,有林地碳贮量最高,其中乔木林碳贮量占比重最大；森林植被碳贮量与树种和龄组密切相关,阔叶树林面积最大,因而碳贮量最多,杉木林碳密度最高,为45.04 t/hm2。乔木林碳密度随林龄增加而增加。不同林种中,特用林林种碳密度最高,为33.87t/hm2。人工林高于天然林；生态公益林中,省级保护等级的碳密度最高；在垂直空间分布上,海拔<500m的森林碳贮量最多,海拔500-1500m森林碳密度最高,反映出不同树种具有不同生物学特性；水平分布上,碳密度30 t/hm2-100t/hm2的面积比例最高,分布在八步区东部的南乡、黄洞林场,大宁镇,西南部的铺门、北部的桂岭、里松和中部的步头等镇。碳密度>150t/hm2主要分布在交通不方便的中部滑水冲保护区、贺街镇东部和黄洞林场。4、利用碳密度分布图和空间变化图分析碳贮量分布规律为：八步区森林植被碳贮量在两次调查期间大幅度增加,主要原因为有林地面积增加,无林地、疏林地面积减少,平均碳密度增加,使碳贮量得以增加；乔木林中除了阔叶树外,杉木、马尾松和桉树的碳密度均增加；幼龄林、中龄林和近熟林的碳密度下降,成熟林和过熟林的碳密度上升。与1999年相比,2009年对应地理位置碳贮量下降的面积为104074.01 hm2,主要分布在黄洞林场和贺街,主要原因是成过熟林采伐更新造成；碳贮量增加0 t/hm2-5t/hm2的面积最大,分布在平原乡镇和人口密集区,源于四旁植树和城镇绿化；碳贮量增加75 t/hm2以上的面积只有122.19hm2,为退耕还林地。针对八步区森林碳贮量分析结果,提出了一列增加碳贮量的森林经营措施和对策。5、采用森林资源二类调查数据估算中小尺度区域森林生物量和碳贮量有以下优点：森林资源二类调查数据具有地域覆盖范围全,林分信息丰富,以及空间分布信息详细,可以建立基于小班的森林植被生物量和碳贮量数据库等优势,可以较全面和较准确地对中尺度的县域范围进行生物量估测；对森林资源二类调查土地类型进行合理的森林植被类型划分,增强了生物量和碳密度估测与森林资源二类调查的兼容性,对不兼容部分提出合理的处理方案,提高了森林植被生物量和碳贮量的估算精度；利用地理信息系统进行矢量数据格网化,便于进行对应地理位置森林植被的碳贮量空间分布的时相变化分析。6、采用方差分析方法对乔木林生物量和碳贮量生态环境定性因子分析,发现地貌类型对杉木、马尾松、桉树和软阔叶树都影响显著,为最重要的影响因子土壤类型、坡向、坡度三个因子分别对其中不同四个树种有显著影响,坡位仅对其它松类和硬阔叶树影响显著,土壤厚度对几个主要树种影响均不显著。其分析结果可用于指导地方森林生产经营。文章指出：利用森林资源二类调查资料还存在诸如缺乏兼容的灌木林等森林类型的生物量估测模型等问题,并提出研制更多的和森林资源二类调查兼容的模型,充分利用生态环境、气象、土壤等多源数据,集成森林生态系统整体估测模型,以便全面估测乔木林、灌木林和竹林的地上和地下的生物量和碳贮量。本文采用的基于森林资源二类调查小班数据,进行县级森林植被生物量和碳贮量估测和特征分析,以及碳密度时空变化分析的方法和技术具有实用价值,可供中小尺度区域进行森林植被生物量和碳贮量的监测和评价借鉴。更多还原

【Abstract】 As the human industrialization and global climate change caused by excessive emissions of CO2 and other gases have threatened the human existence and development. The forecasting of climate change requires accurate estimation of carbon uptake’s amounts and changes in terrestrial ecosystems. Forests are the main part of terrestrial ecosystems and forest ecosystems play an important role in the global carbon cycle. Carbon storage in forest ecosystems is not only the important index reflecting the basic characteristics of forest ecosystems, but also the theoretical basis of the evaluation of the production potential of forest ecosystems and forest structure and function. As a result of a vast terroritory, diverse vegetation types and the complexity of forest ecosystems in China, regional estimates of biomass and carbon storage is a difficulty. According to the region’s natural environment, it is extremely important to select the appropriate research methods and get the statistics of the carbon storage and density of different forest types and in different regions so as to estimate the national or global carbon sink of forest ecosystem. It is of practical significance to find the biomass estimation method being compatible to Forest Resource Inventory and use forest resource survey data for regional estimates of biomass and carbon stocks.In this paper, ecological principles, mathematical statistical methods and GIS spatial analysis techniques are adopted, with the use of the latest data of Forest Management Inventory in Babu County, Guangxi, application of the biomass expansion factor (BEF) which is relatively more mature source to studying the forest biomass and carbon storage in the area, and the analysis of characteristics and spatial distribution of carbon storage, and variance analysis of environment factors to carbon storage. In the study, combining land types of the technical specification of Forest Inventory with the requirements of biomass estimation and the characteristics of the biomass estimation model, the forest vegetation types are divided, the calculation methods of all vegetation types are described accurately, the database of forest biomass and carbon storage is established based on the sub-compart database of forest resources, with producing the maps of forest biomass and carbon storage by the use of geographic information system software, and establishing the biomass and carbon density spatial variation map by the use of vector graphics data gridding method. A study on temporal and spatial changes of carbon storage during 1999 and 2009 has been implemented. The primary results are:(1) 1172180.2t the total amount of forest vegetation biomass, among it, 8283011.3t the tree and shrub layer,1282786.8t under storey carbon storage, and 2146382.lt litter layer carbon storage, in Babu County.(2) 5942324.2t the total carbon storage of forest vegetation,5849565.3t the forest land, only 92758.9t the non forest land, in the whole county. The tree forest belong to forest land is the highest rate with an occupation 88.07% of the total. There are an average of 17.65t/hm2 of total,22.05t/hm2 of woodland, and 23.69t/hm2 of forest of carbon density.(3) The distribution and features are, that the carbon stock of forest vegetation is on the increase with the decrease in population density, and the carbon stock of forest vegetation is related to the land use, the carbon storage amount of forest is the biggest, closed forest is the biggest in which, and the carbon density of timber tree species is the biggest in which. It is shown that the forest carbon storage is closely related to the forest dominant species; the carbon storage of broad-leaved trees in timber forest is the biggest with the largest area, and Chinese fir take the first place of carbon density with 45.04t/hm2. The forest carbon storage is also related to the forest category and age group, the carbon density of special-forest is the highest with 33.87t/hm2, and forest carbon storage is increased with age group. The carbon density of artificial forest is higher than that of natural forest in Babu County. In the ecological public welfare forest, the carbon density of the provincial level of protection is ranked as the highest. In the vertical spatial distribution, the carbon storage is highest in an elevation of less than 500m, but the density of forest carbon is highest in an elevation of from 500m to 1500m, these just reflect that the different species have different biological characteristics. In the horizontal distribution, the carbon density with 15-50t/hm2 is the highest area, which is located in the eastern county of Nanxiang, forest farm of Huangdong Forest Farm, Daning town, the southwest of Pumeng, the north of Guiing, Lisong and the central of Butou town, etc. The area with Carbon density of more than 75t/hm2 is mainly distributed in the middle of inconvenient Huashui protection zone, the east of Hejie town, forest farm of Huangdong.(4) Applied the map of biomass and carbon density to analyzing the temporal and spatial changes uncovers the regulation of that:the carbon storage of forest vegetation increase greatly during 1999 and 2009 for the area of closed forest increased while non stocked land and sparse forest decreased, the mean carbon density increased, results increase of carbon storage. Except the broad-leaved forest, the carbon density of Chinese fir, Chinese red pine and eucalyptus is increased, the carbon density of age group of yang forest, middle age forest and near mature forest are decreased, and mature forest and over mature forest are increased. There is acreage of 103463.07hm2 in which the carbon storage decreased, it scattered over Huangdong Forest Farm and east of Hejie Town for the cutting and regeneration of mature forest and over mature forest, the change class of 0-10t/hm2 has the biggest acreage which distributed the plain towns and district with high density of population for the projects of "plantation of four sides" and "town and city greening ", the change class of over 75t/hm2 is fewer which is land of "return the grain plots to forestry". The paper put forward a series of forest management measures to increase the carbon storage contra posed the analysis result.(5) The advantages of estimating biomass and carbon storage in middle and small scale region with the Forest Management Inventory data are:A geographical coverage of the whole area, the detailed spatial distribution of information, abundant tree information, being able to establish biomass and carbon storage databases based on Sub-compartment, more comprehensive and accurate estimation of biomass in county scope. With reasonable forest vegetation type division according to the land use types of Forest Resource Inventory, we increase the compatibility of biomass and carbon density estimation and Forest Resource Inventory, put up with the reasonable solutions to incompatible parts and improve the estimation accuracy biomass and carbon stock of forest vegetation. Converting vector data into grid with geographical information systems is beneficial to the temporal and spatial variation analysis on carbon storage spatial distribution of matched grids. (6) It has been found with the variance analysis of qualitative ecological environment factors to biomass and carbon storage of forest vegetation:The terrain is the most important factor for it has significant effect on annual carbon density of Chinese fir, Chinese red pine, eucalyptus, and fast grow hard wood. Type of soil, aspects, and slopes affect significantly the annual carbon density of respective four spices, while the slope positions has significant effect only on other pine and hard wood. The Soil thickness has no significant effect on primary tree spices. The results of the analysis can guide local forest management.It point out in the paper, that there are some problems that the estimation biomass model of the bushes and other forest types is incompatible by making use of forest inventory data, and more model being compatible to Forest Inventory should be set up, to fully use multi data resources such as the environment, meteorology, and soil, to integrate the ensemble model to estimate the biomass and the carbon storage above and below ground of the timber forest, shrub forest, and bamboo forest.The methods and techniques of estimation of biomass and carbon storage, its feature analysis, and the temporal and spatial changes of carbon storage with GIS in the county level based the sub-compartments of Forest Inventory have been made by the paper have practical value and making reference of monitoring and evaluating forest vegetation biomass and carbon storage in the small and middle scale region.更多还原