【作者】 徐艳；

【导师】 张凤荣；

【作者基本信息】 中国农业大学 ， 土壤学， 2005， 博士

【摘要】 人口、资源、环境和发展（PRED）成为现今困扰人类的四大问题。其中,全球气候变化已成为各国政府和科学界共同关心的重大问题,因为其不仅是全球环境领域的科学问题,而且是一个涉及到人类社会的生产、消费和生活方式以及生存空间等社会和经济发展的各个领域的重大问题。气候变化领域的国际谈判归结为各主要国家利益集团政治、经济、科技、环境与外交的综合较量,是继WTO后国际多边活动的又一个主要平台。 陆地生态系统土壤碳储量约是大气碳库的2倍,其较小幅度的变动都会引起全球气候较大的变化,成为研究的焦点。我国土壤类型繁多、人类改造强度大,在自然和人类活动的共同作用下,近几十年土地利用/覆被发生了很大变化,通过影响土壤有机碳库的稳定性和CO₂排放,对全球气候变化产生影响。经济因素是诱发“温室效应”的内在驱动因素。本文选择我国北方主要农业生态区——黄淮海区、黄土高原区和东北区的典型县市,计算农业土壤碳储量变化,并应用经济学的原理和方法对其进行解释。主要结论如下: （1） 精确的计算方法是进行土壤碳储量计算的基础,针对耕地土壤有机碳密度和储量的计算方法进行了探讨。土体中有机碳含量在纵向和横向上都具有空间相关性,基于曲周县四疃乡的30个剖面数据,应用纵向拟合法和横向插值法分别计算了该样区的土壤有机碳密度和碳储量。由于两种算法对数据的组织方式不同,得到的土壤有机碳密度和碳储量存在较大差异。两种方法适用于土壤有机碳在剖面中分布形式不同的土壤类型。 （2） 利用68个剖面和1184个表层耕地土壤的有机碳数据,分别对我国北方三个不同的农业生态区,黄淮海平原区、黄土高原区和东北区的耕地土壤有机碳储量变化进行了计算。计算结果表明:黄淮海平原区土壤有机碳密度和有机碳库总量分别增加0.84kgCm^-2和2.06×10¹⁰kgC;黄土高原区土壤有机碳密度和有机碳库总量分别增加1.78kgCm^-2和2.72×10¹⁰KgC;而东北区土壤有机碳密度和有机碳库总量分别减少1.57kgCm^-2和3.60×10¹⁰KgC。黄淮海平原区和黄土高原区土壤有机碳储量增加表明,虽然中国人口众多,对食物和纤维的需求以及国家的粮食安全战略对有限耕地的压力巨大,但是这种压力可能还没有达到净损耗土壤有机碳的临界值,集约化的土地利用方式还没有达到破坏地力的临界点。 （3） 分别计算三个研究区土壤有机碳的收支平衡状况,结果表明:黄淮海平原区的大兴和曲周土壤有机碳有盈余,单位面积分别增加113.5千克/公顷和123.2千克/公顷:黄土高原区的离石和兴县土壤有机碳也有盈余,单位面积分别增加41.5千克/公顷和44.6千克/公顷;东北区的公主岭和海伦土壤有机碳有亏缺,单位面积分别减少598.7千克/公顷和1130.0千克/公顷。与试验获得土壤有机碳储量变化情况结论完全一致。 （4） 利用Janny模型预测模拟耕层土壤有机碳储量及土壤有机碳含量,结果表明:如果继续维持现有的生产状况,十年以后,黄淮海平原区和黄土高原区土壤有机碳储量分别为4.86×10¹⁰kg和1.94×10¹⁰kg,增加0.22×10¹⁰Kg和0.09×10¹⁰kg。东北区土壤有机碳储量为9.14×10¹⁰kg,减少0.60×10¹⁰kg。 （5） 针对三个农业生态区土壤有机碳储量的变化,分别从制度经济学、土地经济学、农户经济学、环境经济学的角度对土壤有机碳储量变化进行解释。 通过对比宏观政策与农产品收购价格之间的对应关系出发,划分出我国农业经济体制更多还原

【Abstract】 Today, population, resources, environment and development are becoming the most difficult problems to trouble people. However, global climate change is the key issue cared by multilateral governments and the researchers. It is not only a science item in the field of global environment, but an important problem in connection with society and economy development fields, such as producing, consumption, life style and living space. The international negotiation about climate change is a focus on the integrated comparison of most country interest groups about politics, economy, science and technology, environment and diplomacy. It has become another significant flatform of international multilateral activities after WTO.The storage of soil organic carbon （SOC） in terrestrial ecological system is twice as much as that in atmosphere. It has become a hotspot for a minimal fluctuation of SOC might bring .about great change of global climate. Because of large variety of soil types and anthropic action of high intensity, land use/cover in China has changed much in recent decades under the associated influence of natural and anthropic activity, which have great effects on global climate through affecting the stability of SOC and the release of CO₂. Economic factors have intrinsically driving forces on "greenhouse effect". Taking typical counties in the Huang Huai-hai Plain, the Loessial Plateau, and Northeastern Plain for case studys, this paper computed the storage of SOC and its change, and delivered its explain using principles and methods of economic science. The main conclusions are as follows:（1） As accurate methods are the bases of computing, the methods of calculating the density and storage of SOC were studied. As the content of SOC is interrelated spatially at both vertical and horizontal direction in soil, the methods for simulating the distribution of SOC in vertical and horizontal were employed to calculate the density of SOC and the storage of SOC in research area, based on the data of 30 soil profiles of Situan town, Quzhou county. The different results are duo to the difference of calculating methods that organize the data from different way. The two methods are suitable to different soils that are different in soil organic matter distribution.（2） For analyzing the changes of SOC, 130 soil profiles and 1184 surface layer soil samples were collected from farmlands in the three agro-ecological zones, and the SOC content of these samples were analyzed and the storage of SOC were calculated respectively. The results are as followings: the SOC density and the SOC storage increased 0.84kgC m^-2 and 2.06 × 10¹⁰kgC respectively in the Huang Huai-hai Plain; the SOC density and the SOC storage increased 1.78kgC m^-2 and 2.72 × 10¹⁰kgC respectively in the Loess Plateau; the SOC density and the SOC storage decreased 1.57kgC m^-2and 3.60×10¹⁰kgC respectively in the Northeastern China. The increase of SOC in the Huang Huai-hai Plain and the Loess Plateau indicates that China was under the stress of a great demand of food, fiber and cultivated land for food security strategy because of its large population. However, the stress has not reached the threshold of net releasing SOC, which showed that the intensive land use at current level can’t destroy the productivity of cultivated land still.（3） Through analyzing the balance between input and output of the soil organic carbon （SOC） in three research regions, the results are as follows: there are SOC surplus in the Huang Huai-hai Plain, 113.5kg ha"1 increased in Daxing county, 123.2 kg ha’1 in Quzhou county. The same result appears in the Loess Plateau, 41.5 kg ha"’ increased in Lishi county and 44.6 kg ha"1 in Xing county. However, it has a deficit of SOC in Northeastern China, 598.7 kg ha"1 decreased in Gong Zhu-ling and 1130.0 kg ha’1 in Hailun. This result is consistent with the change of SOC Storage through experimentation.（4） Forecasting and simulating the SOC storage and SOC content using Janny model, the results show as follows: if keeping the curren更多还原