煤矸石充填复垦土壤团聚体稳定性及其有机碳组分特征研究

发布时间：2018-04-17 04:35

本文选题：复垦土壤 + 土壤团聚体　；参考：《中国矿业大学》2017年硕士论文

【摘要】：我国煤炭开采以井工开采为主,而由其所导致的土地塌陷问题也日益凸显,高潜水位采煤沉陷区的土地复垦与生态重建是当前面临的紧迫任务之一。作为表征土壤质量和生态特性的关键指标,团聚体和有机碳的演变规律研究对评估复垦土壤的质量变化和生态效应、指导复垦土壤改良有重要意义。本文以东滩矿煤矸石充填复垦土壤为研究对象,采用“空间代时间”的方法,分析了时间序列和不同利用方式下土壤基础理化性质、水稳性团聚体分布及稳定性、土壤有机碳、团聚体有机碳含量及贡献率的演变规律与差异特征;并利用密度和大小分组相结合的方法,对团聚体有机碳组分进行分离,研究了土壤团聚体外游离轻组有机碳(f ree LF)、团聚体内颗粒有机碳(iPOM)及矿物结合态有机碳(Mineral-C)的分布及变化特征。主要结果及结论如下:(1)复垦土壤各粒径水稳性团聚体中细大团聚体占绝对优势(50.05%~59.37%)。随着复垦年限的延长,土壤大团聚体含量逐渐增加,团聚体稳定性不断提高。表层土壤细大团聚体质量分数表现为:农田(54.26%)林地(52.75%)荒地(52.18%),农田的团聚体改善效果要优于林地与荒地。(2)土壤有机碳含量、有机碳密度均随复垦年限不断增加,且在复垦13~15年时均已高于对照农田水平,表明矿区复垦土壤在良好的环境条件与合适的管理措施下,其固碳能力甚至会超过自然土壤。复垦土壤表层固碳速率先升高后降低,约在复垦13年时达到最大(约0.186 kg m-2 yr-1)。相关分析表明,复垦土壤有机碳的增加与水稳性大团聚体的形成密切相关。(3)复垦土壤有机碳含量随土壤团聚体粒径的减小而减小。复垦土壤有机碳的主要贡献来源于细大团聚体,与其较高的质量分数有关。随复垦年限的延长,各个粒径团聚体有机碳含量均在逐渐增加,但大团聚体有机碳的贡献率随复垦年限先逐渐提高,复垦13~15年时又开始逐渐降低,微团聚体有机碳的贡献率正好相反。另外,复垦土壤表层有机碳含量、有机碳密度和团聚体有机碳含量均高于20~40cm土层,其对揭示复垦土壤有机碳的转化与积累过程具有重要意义。(4)随复垦年限的延长,土壤细大团聚体和微团聚体free LF、iPOM含量均明显增加。其中,细大团聚体外free LF含量高于微团聚体外free LF含量,反映了土壤中的新鲜植物残渣首先结合进入大团聚体,而微团聚体中细颗粒有机碳在复垦土壤有机碳含量提升过程中起着关键的作用。复垦土壤大团聚体周转在复垦5~15年间先降低后加快。Mineral-C也随复垦年限呈增长趋势,是土壤有机碳固存的重要组成部分。复垦7年后的林地土壤总free LF含量均显著高于农田与荒地,与耕作农田表层的植被残留物相比,微生物的活性可能更有利于土壤团聚体外free LF在林地土壤中的积累。而复垦土壤总iPOM含量和总Mineral-C含量的大小关系均为R7L7H7,且均与R0.25及SOC呈极显著正相关关系(p0.01),表明复垦7年时团聚体内iPOM含量和Mineral-C含量主要受大团聚体含量和总有机碳含量的影响。(5)土壤团聚体外free LF含量占总有机碳的比例为4.38%~10.72%,虽然其对耕作措施、土地利用方式的响应极为敏感,但多受动植物残渣的输入、土壤小气候和土表状况的影响,与团聚体团聚过程关系不大。土壤团聚体有机碳组分含量及占总有机碳比例的大小为:Mineral-CiPOMfree LF,Mineral-C占总有机碳比例最高(40.68%~49.18%)。随复垦年限的延长,free LF增长先快后慢、Mineral-C先慢后快,说明有机碳进入土壤后首先在free LF存储,然后再向团聚体内iPOM和Mineral-C转化。这一有机碳的转化和积累过程与土壤团聚体形成过程密切相关的,符合“团聚体周转”概念模型。
[Abstract]:China's coal mining to underground mining, and the resulting land subsidence problems have become increasingly prominent, Gao Qian level of mining subsidence area of land reclamation and ecological reconstruction is one of the urgent task. As a key indicator for assessing soil quality and ecological characteristics, research on the evolution of the agglomerates and organic carbon on Evaluation of reclaimed soil quality change and ecological effect, has important guiding significance to the improvement of reclaimed soil. Dongtan coal gangue filling reclamation soil as the research object, using the method of "space time", analyzed the time sequence and different soil basic physical and chemical properties, water stable aggregate distribution and stability, soil organic carbon, evolution and characteristics of different aggregate organic carbon content and the contribution rate; and by using a combination of density and size of the packet, the aggregate organic carbon fractions were Study on the separation of soil aggregation in vitro free light fraction organic carbon (f ree LF), agglomerates of particulate organic carbon (iPOM) and mineral bound organic carbon (Mineral-C) distribution and variation characteristics. The main results and conclusions are as follows: (1) fine aggregates the reclaimed soil water stable aggregates accounted for absolute advantage (50.05%~59.37%). With the extension of the reclamation time, soil aggregate content increased gradually, aggregate stability continues to increase. The mass fraction of soil fine aggregate surface for farmland woodland (54.26%) (52.75%) (52.18%), farmland, wasteland and forest improvement is better than the aggregate land. (2) soil organic carbon the content of organic carbon density increased with increasing years of reclamation, and reclamation in 13~15 years were higher than that of the control level of farmland, showed that the reclaimed soil in good conditions and appropriate management measures, the carbon sequestration capacity even More than natural soil reclamation. Soil carbon sequestration rate increased first and then decreased, reached the maximum at about after 13 years (about 0.186 kg m-2 yr-1). Correlation analysis showed that soil organic carbon increased with reclaimed water stable aggregates are closely related. (3) the content of soil organic carbon reclamation with soil aggregate the diameter decreased. Soil organic carbon reclamation main contribution from the fine aggregate, the mass fraction of its higher. With the extension of the reclamation time, particle size aggregates organic carbon content were gradually increased, but the aggregate organic carbon contribution rate with the reclamation time increased at first, and 13~15 years of reclamation began to gradually reduce, micro aggregate organic carbon contribution rate is just the opposite. In addition, the surface soil organic carbon content in organic carbon density and soil organic carbon content was higher than that in 20~40cm soil layer, to reveal the reclaimed soil It is important and significant to the process of accumulation of organic carbon conversion. (4) with the extension of reclamation, soil fine aggregates and micro aggregates of free LF, iPOM was significantly increased. Among them, the fine aggregate of free LF was higher than that of micro aggregates of free LF content, reflects the soil fresh plant residue firstly combined into large aggregates, and micro aggregates in fine particulate organic carbon in the reclaimed soil organic carbon content in the process of ascension plays a key role. The reclaimed soil aggregate turnover decreased in 5~15 years after reclamation accelerate.Mineral-C with reclamation years showed a rising trend, is an important component of soil organic carbon sequestration of soil total free LF. In 7 years after reclamation were significantly higher than that of farmland and wasteland, compared with tillage farmland surface vegetation residues, microbial activity may be more conducive to soil aggregation in vitro free LF in forest soil The accumulation of soil. While the size of reclaimed soil total iPOM content and total Mineral-C content was R7L7H7, and with R0.25 and SOC showed significant positive correlation (P0.01), shows that after 7 years of reunion in the iPOM content and Mineral-C content is mainly affected by the aggregate content and total organic carbon content (. 5) soil aggregation in vitro free LF content in the ratio of total organic carbon is 4.38%~10.72%, although the way of farming measures, land use response is very sensitive, but many plant and animal waste input, the effects of soil microclimate and soil surface conditions, and the aggregate aggregation process has little relationship. Soil organic carbon. The content of total organic carbon and the proportion of the size: Mineral-CiPOMfree LF, Mineral-C accounted for the highest proportion of total organic carbon (40.68%~49.18%). With the extension of the reclamation time, free LF grew fast after a slow first Mineral-C soon after the first slow, organic carbon After entering the soil, it was first stored in free LF and then transformed into iPOM and Mineral-C in the agglomerate. The transformation and accumulation process of organic carbon is closely related to the formation process of soil aggregates, and conforms to the conceptual model of aggregate turnover.

【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD849.5;TD88

【参考文献】