自然资源部岩岩溶动力学重点实验室

岩溶区土壤溶解有机碳对石灰岩的侵蚀作用及环境效应

2010-03-12KDL 652

项目名称:岩溶区土壤溶解有机碳对石灰岩的侵蚀作用及环境效应

项目负责人:曹建华

起止年限:2005-01~2007-1

总经费:31万人民币

经费来源:国家自然科学基金委员会

项目简介:
  结题中文摘要 桂林丫吉岩溶峰丛洼地(灌丛群落为主)土壤溶解有机碳(DOC)的动态观测(每月1次),揭示土壤DOC随季节变化的3个过程:3-7月,土壤生物活性增强,土壤DOC含量升高;8-11月,气温高,降雨少,土壤干燥,土壤生物活性很弱,土壤DOC含量最低;12-次年2月,温度低,生物活性低,而土壤DOC含量缓慢升高。土下石灰岩溶蚀速率与土壤DOC含量成负相关;桂林毛村岩溶区与非岩溶区(森林群落为特征)土壤DOC的动态对比观测(每月2次),揭示非岩溶区土壤pH值比岩溶区低1~2个单位,土壤DOC含量高出5.6~7.3倍,而土下石灰岩的溶蚀速率提高2.6倍;桂林毛村不同果园(桃树、板栗、银杏)中土壤DOC的对比动态监测(每月1次)结果显示:按板栗、桃树、银杏依次降低。贵州茂兰自然保护区内不同土地利用下(林地、草地、耕地)土壤DOC的动态观测(每月1次),结果显示:林地土壤DOC在全年绝大部分时段内大于草地和耕地,从全年平均值来看,林地土壤DOC分别比草地和耕地高25%、48% ;耕地在8月份土壤DOC达到最大值181.56mg/kg,这与黄豆在该月份达到成熟期有关。 

结题英文摘要 The observations on soil dissolved organic carbon(DOC) dynamics monthly in the Yaji peak-cluster depression area indicates the following:The changes of soil DOC could be expressed 3 stages during the observation: (1) From March to July, the soil DOC gradually increased with the temperature, rainfall, the activities of soil organisms, and metabolism; (2) From August to November, the temperature was kept high, however, the rainwater was substantially reduced. The soil became very dry and the soil microorganisms' activities greatly decreased. The concentration of DOC in soil solution was the lowest; (3) From December to February, both temperature and rainfall were low. The fluctuations of soil DOC, however, were increased, which normally related to the carbon of soil microorganism biomass. The seasonal erosion rates of limestone tablets beneath the soil were negatively correlated with soil DOC. The contrast observations on soil dissolved organic carbon(DOC)dynamics twice per month between karst area and non-karst area in Guilin Maocun indicates the following: PH in non-karst area is 1-2 units lower than karst area, and soil organic carbon content in non-karst area is 5.6 times higher than karst area.The seasonal erosion rates of limestone tablets beneath the soil increased 2.6 times. The contrast observations on soil dissolved organic carbon(DOC)dynamics monthly under different o