| 表层岩溶生态系统碳循环特征研究 |
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| 引用本文： | 何师意,潘根兴,曹建华,陶于祥,滕永忠.表层岩溶生态系统碳循环特征研究[J].第四纪研究,2000,20(4):383-390. |
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| 作者姓名： | 何师意 潘根兴 曹建华 陶于祥 滕永忠 |
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| 作者单位： | [1]中国地质科学院岩溶地质研究所国土资源部岩溶动力学开放 [2]南京农业大学农业资源与生态环 |
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| 基金项目： | 国家自然科学基金!（批准号：49632100），国土资源部重点科技项目!（批准号：9501104），国土资源部科技司“十五”预 |
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| 摘 要： | 本文以广西桂林丫吉试验场的实际观测资料为基础，应用同位素示踪方法，探索了整个系统中碳的输入、输出和转移问题，并分析了表层岩溶生态系统中泉水水化学、土壤 CO2浓度及近地表植被层空气中CO2浓度的变化特征。结果显示，泉水水化学主要组分的日变化不明显，而土壤中CO2浓度则明显受日气候变化的影响，两者存在明显的滞后关系。用碳同位素示踪方法，重点对桂林观测站表层生态系统各碳库间碳的转移过程进行了定量研究，认为在有土壤层和植被覆盖的表层岩溶生态系统中，参与岩溶作用的碳有一半以上来源于与生物作用有关的碳。
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| 关 键 词： | 表层岩溶生态系统 碳循环 |
| 收稿时间： | 2000-04-09 |
| 修稿时间： | 2000-04-09 |
RESEARCH ON CHARACTERISTICS OF CARBON CYCLE IN EPI-KARST ECOLOGICAL SYSTEM |
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| He Shiyi, Pan Genxing, Cao Jianhua, Tao Yuxiang, Teng Yongzhong.RESEARCH ON CHARACTERISTICS OF CARBON CYCLE IN EPI-KARST ECOLOGICAL SYSTEM[J].Quaternary Sciences,2000,20(4):383-390. |
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| Authors: | He Shiyi Pan Genxing Cao Jianhua Tao Yuxiang Teng Yongzhong |
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| Institution: | He Shiyi
;(Institute of Karst Geology, Chinese Acaudemy of Geological Sciences; Karst Dynamics Laboratory, Ministry of Land and Resources, Guilin 541004);Pan Genxing
,Cao Jianhua
;(lnstitute of Resources, Ecosystem and Enviromnent for Agriculture, Nanjing Agricultural University, Nanjing 210095);Cao Jianhua
;(Institute of Karst Geology, Chinese Acaudemy of Geological Sciences; Karst Dynamics Laboratory, Ministry of Land and Resources, Guilin 541004);Tao Yuxiang
,Teng Yongzhong
;(lnstitute of Resources, Ecosystem and Enviromnent for Agriculture, Nanjing Agricultural University, Nanjing 210095) |
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| Abstract: | A biogeochemical model, DNC, was employed for predicting soil organic carbon (SOC) dynamics in agricultural ecosystems in both China and the U. S. at national scale. Data of 1990 climate, soil properties, crop types and acreage, and cropping management at county scale were collected from various sources and integrated into a Geographic Information System (GIS) dhabase to support the model runs at the regional scale. The predicted results revealed that the agricultural lands in the U. S. were gaining SOC at a rate of 72.4Tg C / year, and the agricultural lands in China were loosing SOC at a rate of 73.8Tg C/ year. The U, S. soils released 812Tg C as carbon dioxide (CO2) into the atmosphere, and obtained 884Tg C as crop residue annually. China soils released 366Tg C as CO2, and obtained 293Tg C as crop residue annually. The difference in crop residue management was one of the major reasons, which caused SOC increase in the U. S. and decrease in China. In comparison to the U S., China soils provide less available nitrogen (N) due to less SOC turnover every year. That is partially why the Chinese farmers have to use much more fertilizer (abollt 16 million tons N per year) for their 95.9 million ha cropland, and the U. S. farmers only use about 8 million tons of N fertilizer in their 143.6 million ha cropland. Overuse of fertilizers will not only degrade the soil quality but also cause regional and global environmental problems. Since SOC is an essential element determining soil physical and chemical properties, loss of SOC will cause soil degradation, which does not only undermine sustainable yield but also affect environmental safety. Desertification and dust storm currently prevailing in China are one of the inherent consequences of SOC loss at regional scale. The DNDC model tested several alternative management, such as land cover changes, conservative tillage and increased percentage of crop residue returned back to the field after harvest, and found they were able to effectively increase SOC in the cropland in China. China needs a long-term policy based on scientific analysis to protect her soil resources if she wants to maintain the soil fertility, sustainable yield, and environmental safety in the county. |
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| Keywords: | epi-karst ecological system carbon cycle |
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