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我国水平地带性土壤中有机质的空间变化特征 总被引：18，自引：4，他引：18
主要根据全国第二次土壤普查的成果，对我国水平地带性土壤中有机质的含量和胡敏酸与富里酸比值的空间变化特征进行了概括，进而探讨了在不同自然和人因素影响下，土壤有机质的累积状况与稳定性特征。 相似文献
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从土壤腐殖质分组到分子有机质组学认识土壤有机质本质 总被引：2，自引：0，他引：2
梳理了与土壤生态系统功能相联系的,特别是对固碳减排的土壤有机质本质认识的研究进展及路径,探讨了经典腐殖质学说存在的问题,概述了新近的有机质保护稳定学说及腐殖质组学学说,并追溯了生物标志物有机质分子研究,最后从土壤学的基本理念和理论出发讨论和重新认识土壤有机质的本质及其价值。从形成条件、分离条件和分子鉴定等多方面分析,土壤腐殖质形成和稳定学说越来越显示出局限性;而面向气候变化的碳固定研究可以深入探析土壤有机质的复杂存在状态。越来越认识到土壤有机质是投入土壤的有机物质经不同程度生物利用或降解的产物残留,只是被土壤不同程度地区隔和封闭,本质上仍是分子量变化极大的生命源有机物的集合。因此,可通过生物标志物分子作为靶标在土壤中提取和识别,该技术的发展将孕育萌生土壤有机质分子组学。后者可以用于判读土壤有机质的结构支撑、反应活性和促生功能等方面的本质差别,这些差别可能是由有机分子组成结构及存在状态所决定而不是由有机分子稳定性决定的。从这个概念出发,类似于土壤微生物分子生态,土壤有机质的丰度、组成、结构与功能间的联系可能是土壤有机质本质的核心问题。对这种关系的量化和参数化表征可用以探索土壤有机质永续固定,且可以保持生命活性的土壤有机质的管理策略及技术,并配合土壤的团聚体理论诠释土壤的本质和生态系统功能服务,这将是未来土壤学服务人类可持续发展的理论立足点。 相似文献
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Bruce. E. Broster Marni L. Dickson Michael A. Parkhill 《Journal of Geochemical Exploration》2009,103(2-3):115-132
Thirty-nine elements in humus and till matrix were compared at 109 sites overlying Ag–As–Cu–Mo–Pb–Zn mineralized occurrences in northeastern New Brunswick to assess humus for anomaly identification. Humus element concentrations were not consistently correlative with maximum or minimum concentrations found in the underlying till or bedrock. The humus demonstrated significantly higher mean elemental concentrations than the till for six specific elements: 9 times greater for Mn, 6 times greater for Cd, 5 times greater for Ag and Pb, 3 times greater for Hg, and double the concentration of Zn. Spatial dispersal patterns for these elements were much larger for humus content than that exhibited by the till matrix analysis, but did not delineate a point source. For elements in till, the highest concentrations were commonly found directly overlying the underlying mineralized bedrock source or within one km down-glacier of the source.The complexity of the humus geochemical patterns is attributed to the effects of post-glacial biogenic, down-slope hydrodynamic and solifluction modification of dispersed mineralization in the underlying till, and the greater capacity of humus to adsorb cations and form complexes with some elements, relative to the till matrix. Humus sampling in areas of glaciated terrain is considered to be mostly valuable for reconnaissance exploration as elements can be spatially dispersed over a much larger area than that found in the till or underlying bedrock. 相似文献
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Exploring the Nature of Soil Organic Matter from Humic Substances Isolation to SOMics of Molecular Assemblage 总被引：4，自引：0，他引：4
Genxing Pan Yuanjun Ding Shuotong Chen Jingling Sun Xiao Feng Chen Zhang Doross Marios Jufeng Zheng Xuhui Zhang Kun Cheng Xiaoyu Liu Rongjun Bian Lianqing Li 《地球科学进展》2019,34(5):451-470
In this review, the evolution of Soil Organic Matter (SOM) research was traced back to outline the main achievement of understanding SOM in relation to its ecological functioning, particularly of carbon sequestration against climate change. The short-coming of soil humus theory, knowledge of SOM protection and stabilization, framework of newly emerged Humeomics as well as the increasingly active study of molecular organics in soils were analyzed and discussed, highlighting the importance of re-visiting SOM in term of structure-property-functions for the main mission of modern soil science. There were limitations of soil forming conditions, fraction separation procedure and single molecule identification for understanding the huge complex humus of larger sized synthesized molecules. Thanks to the ever-active studies of soil (organic) carbon sequestration and stabilization focusing on the association status of SOM with soil components, SOM has been increasingly recognized as an assemblage of metabolites from life activities on or in soil, with different allocation or protected in mineral/organic complex phases, which could be traced by biomarker molecules. Using such biomarker molecules as a target (like primer in molecular microbiology), all the molecules of SOM could be digested and isolated for qualitative or quantitative identification with GC/MS high resolution technologies. Such development has emerged a new paradigm of molecular SOM study, finally as SOMics as a modern soil science frontier. The functioning of SOM for stabilizing soil structure, enhancing reactivity and promoting biological resistance could be correlated to the paradigm of abundance, composition, structure and functions rather than the content and recalcitrance of SOM. This may deserve urgent studies to quantify and parameterize the defined paradigm based on the molecular composition of SOM. Again, such theory and technology development could provide a tool to manage SOM in term of carbon sequestration but revalorizing bioactivity in ecosystems, especially in agroecosystems. We believe such studies could rather depict the nature of SOM and of soil in relation to its ecological services and functioning, which will be the focus of soil science in serving the sustainable development of human society. 相似文献
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池塘淤泥对水中氮营养盐影响的初步研究 总被引：3，自引：0，他引：3
通过对不同厚度淤泥水中氮营养盐的测定和分析,初步研究了不同厚度淤泥对水族箱水质环境中氮营养盐的影响。实验结果表明,有淤泥水族箱水中的氨氮浓度与无淤泥水族箱水中氨氮浓度差异显著,且有淤泥水中的氨氮浓度变化幅度较小。有淤泥水族箱水中硝酸盐和亚硝酸盐浓度显著高于无淤泥水体,10cm厚淤泥水中亚硝酸盐浓度变化较5cm厚淤泥水体稳定。由此说明,养殖水体需要一定厚度的淤泥来维持和缓冲水体中各营养盐水平。 相似文献
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A hydrochemical investigation was carried out in spring, summer, and autumn, in the years 1991–1994, in three dystrophic lakes of the Wigry National Park (NE Poland). In spite of the fertile catchment basin, the developing ombrofile peat bogs of lake environment results in the acidification of lakes, the presence of small concentrations of dissolved mineral substances (below 50 mg L–1), and exceptionally high DOC concentrations, exceeding 10 mg L–1 C. During summer, a strong thermic stratification develops in the lakes, with constant conditions of oxygen deficiency prevailing below 3 m. In the course of the spring and autumn mixing of dystrophic lakes, the deterioration of oxygen conditions occurs in the epilimnion. In spite of high TP and NH4+ concentrations, which increase from spring to autumn, the conditions developing in the lakes are unfavourable, for the functioning of aquatic organisms, on account of the strong shading. The increased direct irradiation of water bodies caused by deforestation or favourable atmospheric conditions results in an increased trophy of lakes. 相似文献
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