【作者】 洪滔；

【导师】 吴承祯；

【作者基本信息】 福建农林大学 ， 森林经理学， 2009， 硕士

【摘要】 森林生物量与森林碳贮量大小是陆地生态系统碳循环和碳平衡研究中的重要部分。近年天然林资源不断减少,导致人工林在森林生态系统中占重要地位。但目前关于人工林生态系统碳汇等的研究并不全面,尤其是针对速生树种的人工林生态系统碳汇研究较少,千年桐是可作为生物质能源的优良速生树种,对其碳汇进行研究在一定程度上促进了我国人工林生态系统碳汇/源的准确评估。以千年桐人工林作为主要研究对象,测定千年桐人工林林分乔木层各器官生物量及含碳率;测定千年桐人工林中灌木层、草本层、凋落物层生物量及含碳率;测定千年桐人工林土壤含碳量,同时建立千年桐人工林乔木层生物量回归模型。为了了解千年桐人工林生命过程以及其空间异质性特征,对不同年龄的千年桐人工林进行了对比研究,目的能够为区域尺度的人工林生态系统碳汇功能,特别是生物能源树种千年桐人工林生态系统碳汇功能研究提供依据。研究在以下方面取得一些进展:1、通过对千年桐解析木各器官生物量的回归分析,建立了千年桐各器官及总生物量的回归模型W = a( D2H)b。该模型具有较好的相关性。千年桐人工林各林龄林分的生物量分别为:9年生林分156.513 t/hm2、7年生分129.225 t/hm2、5年生林分71.046 t/hm2、3年生林分61.677 t/hm2、2年生林分49.730 t/hm2。2、对千年桐人工林各林龄各组分含碳率进行测定,得出乔木层器官(杆、枝、叶、根)、灌木层、草本层、凋落物层、和土壤层(0～100cm)含碳率在不同年龄之间均存在差异。乔木层不同器官含碳率亦存在差异,各器官含碳率大小因林分的发育阶段不同而有所不同,其中9年生林分乔木层各器官含碳率大小变化为树杆>树根>树枝>树叶,各林分总体上以树杆和树叶含碳率较高,树枝和树根较低;不同年龄同种器官碳含量没有表现出显著随年龄一致变化的现象,但总体上是随林龄而增加;各林龄乔木层含碳率平均值没有表现出随年龄变化的一致性。不同年龄的千年桐人工林林下植被层和凋落物层含碳率存在着差别,各年龄整体在层次上含碳率一致表现为凋落物层>灌木层>草本层。其中,灌木层中含碳率大小顺序依次为9年生>7年生>5年生>3年生>2年生,草本层中含碳率大小顺序依次为7年生>9年生>5年生>3年生>2年生,凋落物层中含碳率大小顺序为:9年生>7年生>5年生>3年生>2年生。各林分土壤含碳率均随土壤深度的增加而降低,表现出较明显的梯度变化,同时土壤各层含碳率随着林分年龄的增长表现出增长的规律;随着土壤深度的增加,各层增长的幅度在缩减,差异在缩小。年龄大的林分土壤各层含碳率高于相应的年龄小的林分。千年桐人工林土壤碳储量在人工林生态系统总碳储量中的比重却表现为随林龄增大而降低的趋势,而乔木层碳储量在总碳储量中的比重均表现为随林龄增大而增加的趋势。3、千年桐人工林生态系统总碳储量分别为:9年生214.58 t/hm2、7年生186.59 t/hm2、5年生140.18 t/hm2、3年生147.83 t/hm2、2年生105.59 t/hm2。9年生林分植被碳储量(85.115 t/hm2)略低于鼎湖山季风常绿阔叶林(89.75 t/hm2)和全球森林碳储量的平均值(86 t/hm2)。9年生和7年生林分植被碳储量均高于我国森林碳储量的平均值(57.07 t/hm2)以及浙江青冈常绿阔叶林(66.113 t/hm2)。9年生千年桐林植被活体的碳储量(78.786 t/hm2)高于我国森林碳储量的平均值(57.07 t/hm2),也大于浙江青冈常绿阔叶林(66.113 t/hm2),但小于全球森林碳储量的平均值(86 t/hm2)。9年生、7年生、5年生、3年生林分林土壤的碳储量均高于鼎湖山南亚热带常绿阔叶(89.128 t/hm2),但都低于我国森林土壤碳储量的平均值(193.55 t/hm2)。更多还原

【Abstract】 Forest biomass and carbon storage play a significant role in the study of carbon cycle and balance of terrestrial ecosystem. In recent years, with the continually deceasing of natural forests, plantations are dominant in forest ecosystem. However, the present researches in carbon sink of plantation ecosystem are far beyond abundant, especially in the plantations of fast growing species. As fast growing tree species for bio-energy, the study of carbon sink of Aleurites Montana contributes to some degree to the appropriate assessment of carbon sink or carbon pool in plantation ecosystem of our country.In this paper, the Aleurites Montana plantations were studied on the biomass and carbon content rates in the organs of the tree layer and in the shrub layer, herb layer and litter layer and the carbon content in the soil, together with building regression model of tree-layer biomass. By comparing uneven-aged Aleurites Montana plantations, the growing process and spatial heterogeneity characteristics were exhibited to provide practical basis for regional carbon sink in plantation ecosystem, especially in Aleurites Montana plantation ecosystem. The researches were carried out in the following parts:1. By regression analysis of the biomass in the organs of analytic Aleurites Montana trees, the regression model W = a( D2H)b, with fair correlation, was established for the organ and total biomass. The biomass of uneven-aged Aleurites Montana plantations included: 9-year-old plantation as 156.513 t/hm2, 7-year-old plantation as 129.225 t/hm2, 5-year-old plantation as 71.046 t/hm2, 3-year-old plantation as 61.677 t/hm2 and 2-year-old plantation as 49.730 t/hm2.2. By determining the carbon content rates of all components in uneven-aged Aleurites Montana plantations, the conclusion was drawn that the carbon content rates varied with tree ages in the tree layer (stem, branch, leaf and root), the shrub layer, the herb layer, the litter layer and the soil layer (0-100cm). The carbon content rates differentiated in the organs of the tree layer as well, varying with the development stages, among which the carbon contents rates of the organs in 9-year-old tree layer were in the sequence of stem>root>branch>leaf. Comprehensively, the carbon content rates were comparatively higher in stems and leaves while lowers in branches and roots for the plantations. The carbon content rates of the same organs in different ages didn’t vary proportionately with ages, but generally exhibited the tendency of increasing with tree ages. The average carbon content rates in uneven-aged tree layers didn’t present the tendency of varying correspondingly with tree ages.In uneven-aged Aleurites Montana plantations, the carbon content rates of the vegetation layer under canopy differentiated with those of the litter layer and generally in the sequence of the litter layer>the shrub layer>the herb layer. The carbon content rates in the shrub layer were in the sequence of 9a>7a>5a>3a>2a, in the herb layer were 7a>9a>5a>3a>2a and in the litter layer were 9a>7a>5a>3a>2a.The carbon content rates of the soils in the plantations decreased with the increase of soil depth, showing apparent gradient changes. The carbon content rates of all soil layers increased with the increase of tree ages. With the increase of soil depth, the increase of carbon content rates slowed down. The carbon content rates of the soil layers in the aged plantations were higher than those in the young plantations. The proportion of soil carbon contents of Aleurites Montana plantations in the total carbon contents of plantation ecosystem exhibited the tendency of decreasing with age growth, while the proportion of tree-layer carbon contents in the total carbon contents presented the tendency of increasing with age growth.3. The total carbon contents of Aleurites Montana plantation ecosystem were respectively 9a plantation as 214.58 t/hm2, 7a plantation as 186.59 t/hm2, 5a plantation as 140.18 t/hm2, 3a plantation as 147.83 t/hm2 and 2a plantation as 105.59 t/hm2. The vegetation carbon content of 9a plantation (85.115 t/hm2) was a little lower than that of monsoon evergreen broad-leaf plantation in Dinghushan (89.75 t/hm2) and the average of global forest carbon content (86 t/hm2). The vegetation carbon contents of 9a and 7a plantations were both higher than the average of national forest carbon contents (57.07 t/hm2) and those of evergreen broad-leaf plantation in Zhejiang Qinggang (66.113 t/hm2). The carbon content of vegetation biomass of 9a plantation (78.786 t/hm2) was higher than the average of national forest carbon contents (57.07 t/hm2) and that of evergreen broad-leaf plantation in Zhejiang Qinggang (66.113 t/hm2), but lower than the average of global forest carbon content (86 t/hm2). The soil carbon contents of 9a, 7a, 5a and 3a plantations were all higher than that of monsoon evergreen broad-leaf plantation in Dinghushan (89.128 t/hm2),but lower than the average of national forest soil carbon content (193.55 t/hm2).更多还原