【作者】 李江；

【导师】 黄从德； 张小全；

【作者基本信息】 四川农业大学 ， 森林经理学， 2008， 硕士

【摘要】 土壤碳循环和碳蓄积研究是当前陆地生态系统碳循环以及全球变化研究的热点内容之一。土壤有机碳库储量是全球温室气体的一个主要源和汇,同时土壤作为人类生存和发展的基底环境,很容易受到人类活动影响,土壤碳库的轻微变动都有可能引起大气环境和陆地生态系统的迅速响应。研究陆地土壤碳蓄积现状和碳循环过程的控制及反馈机制,是预测大气CO₂含量及全球气候变化的基础,也是合理有效利用土地资源,缓解温室效应的依据。森林土壤在全球碳循环中起着重要作用,对森林土壤碳储量进行比较细致的调查,有助于对森林土壤碳蓄积在全球碳循环中的地位进行准确地评估,也有利于全球大气碳平衡的计算。本文首先论述了森林生态系统土壤有机碳格局及其影响因子的研究进展。利用已有文献与著作资料中的我国森林土壤剖面数据资料以及实地采样数据,结合1:400万的土壤类型图、全国人工林与天然林分布图和全国森林资源清查数据估算了我国主要森林群落林下土壤碳库储量,并分析了土壤碳密度的垂直分布特征与空间分布特征。结合各剖面点的气温、降水、海拔高度、植被和土壤养分及质地状况的相关关系对其分布的影响因子进行分析。通过分析研究,得到以下初步结论:（1）森林土壤有机碳垂直分布格局:利用全国森林现有的土壤剖面数据,分析其有机碳在不同深度间隔土层中的垂直分布特征,得出有机碳主要储存在0～20cm土壤中,随着土层深度增加,有机碳储量逐渐减小。其中0～40cm之间,普遍下降比较明显。并不同的分类划分比较下,显示出不同的差异。（2）我国主要森林群落林下土壤有机碳库特征:根据我国森林现有的土壤剖面数据资料,并结合1:400万全国土壤类型分布图、全国森林分区图以及全国各省人工林和天然林面积分布计算可得,全国各省人工林与天然林总面积为169.0163×10⁶公顷,总碳储量值为208.45×10⁸t。土壤平均碳密度为12.33 Kg/m²。中国主要森林（天然林和人工林）面积占我国国土面积（不计算台湾及南海诸岛）的19.26%,其有机碳储量占全国大陆陆地土壤总有机碳储量的22.56%。（3）我国主要森林群落林下土壤碳库空间分布特征:由纬度变化造成的温度变化差异和由经度变化造成的降水量差异对我国森林土壤有机碳密度具有很大的影响。我国主要森林土壤较高的有机碳密度主要分布于（E80°～98°,N27°～36°）和（E120°～133°,N39°～50°）区域。分别从这两个区域向东和向南,森林土壤有机碳密度有明显的递减趋势。（4）森林土壤碳储量的影响因子:分析土壤有机碳与气温、降水和土壤特性的相关关系,结果显示,海拔升高会增加部分地区或部分土层的有机碳密度,但对森林土壤碳的影响并不明显（R=0.58,P＞0.01）;土壤有机碳储量随着全N含量增加而增加（R=0.39,P＜0.01）,且土层加深,全N含量逐渐减少,土壤有机碳密度随之减小,与全P、全K关系不明显;森林土壤有机碳储量随着气温的增加而降低（R=-0.339,P＜0.001）,随着降水量的增加而增加（R=0.495,P＜0.001）;土壤PH值与有机碳含量表现出一定的负相关关系,但并不显著（R=-0.046,P＞0.01）;森林土壤有机碳含量随着容重的增大而减小（R=-0.445,P＜0.001）。更多还原

【Abstract】 Soil carbon cycle and carbon sequestration research is one of the spots in the current terrestrial ecosystem carbon and global researches . The soil organic carbon reserves is the main sources and sinks of global greenhouse gas . As the basement of human existence and development, soil is vulnerable to human activities . The rapid reponse of atmospheric environment and terrestrial acosystems may be caused by the minor change of the soil carbon . The research on land soil carbon stored status and the carbon cycle process control and feedback mechanisms , is the basement of forecast atmospheric CO₂ levels and global climate change , is the basis for the use of land resources and the mitigation of greenhouse . Forest soil play an important role in the global carbon cycle . The investigation to the forest soil carbon reserves conducive to evaluat accurately the status of the forest soil carbon storage in the global carbon cycle , also conducive to the calculation of the global atmospheric carbon balance .Current researches on forest ecosystem soil carbon storage are reviewed in this paper . The forest soil carbon reserves of China has been estimated by the use of soil sampling data in exiting literature , field data , 1:400 000 types of soil map and The distribution of natural forests and plantations of China . The vertical and space distribution of soil carbon density were analysised with the temperature , rainfall , elevation, vegetation and soil nutrient and texture .In this paper, the main results are brought forth as follows :（1） . The vertical distribution of froest soil organic carbon in China . Base on the soil profiles database of forest in China , the vertical distribution of soil organic carbon was studied . The main organic carbon stored in the 0～20 cm soil , with the increasing depth , organic carbon reserves decreased , more obviously in 0～40 cm . The differences were showed in different categories comparison .（2） . The characters of forest soil carbon pool in China . With soil profiles database of forest in China , 1:400 000 types of soil map , the forest district map and the map of forest area of China , the total area of natural forests and plantations in China is 169.0163×l0⁶hm² . The total carbon storage is 208.45×10⁸t, the average bulk density is 12.33 Kg/m² , China’s forest （natural forests and plantations） area of China’s land area （not calculated in Taiwan and the South China Sea islands） 19.26 % , its organic carbon reserves of the nation’s mainland land soil organic carbon reserves of 22.56% .（3） . The distributing patterns of forest soil carbon pool in China . Temperature differences caused by latitudes change and rainfall differences caused by longitude have great impact to the forest soil organic carbon density in China . The region which the higher forest soil organic density distributed were （E80°～98°,N27°～36°）and （E120°～133°,N39°～50°） . Respectively from the two region to east or south , there’s a significantly decreasing trend in forest soil organic carbon density .（4） . Major factors affecting forest soil carbon storage in China . Study on the correlation between foreset SOC and temperature , precipitation and soil characters was carried out in this paper . Soil carbon density increased with the precipitation , elevation and total nitrogen , but decreased with temperature , there’s a certain negative correlation between the PH and soil organic carbon content , but not obvious ; forest soil organic carbon content decreased with the density increasing .更多还原