陆地硅的生物地球化学循环研究进展  

A Review of the Biogeochemical Cycle of Silicon in Terrestrial Ecosystems

作　　者：陶贞[1,2] 张超[1] 高全洲[1] 李元[1] 

机构地区：[1]中山大学地理科学与规划学院,广东省城市化与地理环境空间模拟重点实验室,广东广州510275 [2]华南地区水循环与水安全广东省普通高校重点实验室,广东广州510275

出　　处：《地球科学进展》2012年第7期725-732,共8页Advances in Earth Science

基　　金：国家自然科学基金项目"青藏高原高寒草甸土壤碳循环同位素示踪研究"(编号:40871143)和"人类活动干预下的流域地表过程在河流碳循环中的响应"(编号:41071054);中国地质调查局地调项目"中国岩溶碳汇动态评价"(编号:岩[2011]地调01-01-23)资助

摘　　要：地球表层硅(Si)的生物地球化学循环与大气CO2浓度变化、大洋生物泵作用以及海岸带富营养化等过程密切相关,因此成为全球环境变化研究的核心问题之一。在地质时间尺度上,硅酸盐矿物的化学风化是地球表层所有次生Si的来源。陆地生态系统各次生Si库具有不同的形成机制和驱动因子,这导致各Si库的贮存量和循环周期存在明显差异。土壤Si库中的黏土矿物Si、溶解硅(DSi)和淀积在其他矿物表面的无定形Si都源自硅酸盐矿物的化学风化过程;植物生长过程中吸收土壤中的DSi形成生物Si,然后经微生物分解过程返还给土壤;地表径流将流域陆源Si以悬移质Si和DSi的形式输入河流、海洋。迄今,陆地不同形态Si库的大小及其对全球Si循环的贡献仍不确定。因此,在研究陆地Si的生物地球化学循环过程中,综合考虑各种地表过程及其耦合作用是非常必要的。The biogeochemical cycle of silicon on the Earth＇ s surface has become a crucial subject of studying global environmental change because of its interconnetion with those processes of the changes of atmospheric CO2 concentration, the oceanic biological pump and the coastal eutrophication. On geological time scales, the chemical weathering of silicate minerals is considered to be the source of overall secondary Si on the Earth＇s surface. There are different formation mechanisms and the driving factors for different secondary Si pools in the terrestrial biogeo- systems, which leads to the difference in the reservoir and turnover time for those Si pools. Secondary silicates in the soils, dissolved Si （DSi） and amorphous silica precipited on surfaces of other minerals are all sourced from the chemical weathering of silicates ; phytogenic Si （BSi） is formed in the growth process of the plants in which the DSi was uptake from the soil. Then, the BSi is subsequently returned to soils; terrestrial Si was also transported to the river and ocean by surface runoff in particulate and dissolved forms. Up to date, there are still a great number of uncertainties in understanding the terrestrial Si cycle concerning the size of various Si pools and their contribution to the global silicon cycle. Hence, it is necessary to consider comprehensively various land surface processes and their coupling effect in the study of the silicon biogeochemical cycles in the terrestrial ecosystems.

关 键 词：化学风化 生物硅 生物地球化学循环 同位素 硅 

分 类 号：P593[天文地球—地球化学]