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石笋与环境——石笋纹层形成的环境机理初探 被引量:53
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作者 谭明 潘根兴 +4 位作者 王先锋 秦小光 滕永忠 宋林华 林玉石 《中国岩溶》 CAS CSCD 1999年第3期197-205,共9页
石笋沉积的生长条带从剖面图式可分为两大类:一类没有明确的沉积旋回界面,难以按层计数,称为“生长纹理”;另一类具有确定的沉积旋回界面,可以按层计数,称为“生长层理”。石笋生长层理可以发展成为一类重要的断代工具。中国北方... 石笋沉积的生长条带从剖面图式可分为两大类:一类没有明确的沉积旋回界面,难以按层计数,称为“生长纹理”;另一类具有确定的沉积旋回界面,可以按层计数,称为“生长层理”。石笋生长层理可以发展成为一类重要的断代工具。中国北方型微层的形成可能主要与干湿季变化明显的气候条件、以及富含有机质和碱性交换态离子的土壤类型密切相关。而南方型微层的形成可能主要与较长时间的降水和有机质淋滤以及盛夏高温少降水的配置有关。如果沉积物中某种要素对物源或水流通过路径的环境变化能够灵敏反应,并按一定的时间单元将这些变化记录下来。 展开更多
关键词 石笋 环境 气候-土壤动力 石笋纹层 气候
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Soil Carbon Dynamics Under Changing Climate A Research Transition from Absolute to Relative Roles of Inorganic Nitrogen Pools and Associated Microbial Processes:A Review 被引量:6
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作者 pratap srivastava rishikesh singh +5 位作者 sachchidanand tripathi pardeep singh shikha singh hema singh akhilesh singh raghubanshi pradeep kumar mishra 《Pedosphere》 SCIE CAS CSCD 2017年第5期792-806,共15页
It is globally accepted that soil carbon (C) dynamics are at the core of interlinked environmental problems, deteriorating soil quality and changing climate. Its management remains a complex enigma for the scientifi... It is globally accepted that soil carbon (C) dynamics are at the core of interlinked environmental problems, deteriorating soil quality and changing climate. Its management remains a complex enigma for the scientific community due to its intricate relationship with soil nitrogen (N) availability and moisture-temperature interactions. This article reviews the management aspects of soil C dynamics in light of recent advances, particularly in relation to the availability of inorganic N pools and associated microbial processes under changing climate. Globally, drastic alterations in soil C dynamics under changing land use and management practices have been primarily attributed to the variation in soil N availability, resulting in a higher decomposition rate and a considerable decline in soil organic C (SOC) levels due to increased soil CO2 emissions, degraded soil quality, and increased atmospheric CO2 concentrations, leading to climate warming. Predicted climate warming is proposed to enhance SOC decomposition, which may further increase soil N availability, leading to higher soil CO2 effiux. However, a literature survey revealed that soil may also act as a potential C sink, if we could manage soil inorganic N pools and link microbial processes properly. Studies also indicated that the relative, rather than the absolute, availability of inorganic N pools might be of key importance under changing climate, as these N pools are variably affected by moisture-temperature interactions, and they have variable impacts on SOC turnover. Therefore, multi-factorial studies are required to understand how the relative availability of inorganic N pools and associated microbial processes may determine SOC dynamics for improved soil C management. 展开更多
关键词 agro-management IMMOBILIZATION NH4+-N to NO3-N ratio NITRIFICATION relative availability soil C02 effiux
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