黄土高原人工与天然植被恢复下土壤固碳特征及其影响机理

发布时间：2018-07-10 13:03

本文选题：土壤有机碳 + 土壤无机碳　；参考：《陕西师范大学》2015年硕士论文

【摘要】：植被恢复与重建是控制水土流失和改善生态环境的重要措施,其固碳效益是衡量区域生态效应的重要依据。本研究采用空间代替时间、野外调查与室内分析相结合的方法,对黄土高原人工和天然植被恢复下的典型样地进行采样和测定分析,探讨了植被恢复重建进程中土壤有机碳库和无机碳库动态变化特征,评估植被恢复与土壤固碳效应的演变关系,阐明影响土壤有机碳和无机碳固定的直接和间接因子,旨在为全面认识和理解以及准确评价黄土高原植被恢复的土壤固碳效应,为更好的阐明植被恢复与土壤碳库间的演变关系提供科学依据,同时为黄土高原植被恢复与重建工作提供科学参考。本研究主要结论如下：1、随人工植被恢复年限的增加,刺槐林土壤固定有机碳(soil organic carbon, SOC)的效应先减少后增加,表层远大于下层,且下层受植被影响不明显。土壤无机碳(soil inorganic carbon, SIC)的固定效应随年限变化不明显,在16.65～20.30kg·m-2波动变化,但改变了淀积层的剖面分布状况；表层SIC含量最低,随土层深度而增加。0-100 cm土壤无机碳库储量是有机碳库的4.5～7.4倍,表明土壤无机碳库对总碳库储存能力的贡献占绝大部分。2、随天然植被恢复年限的增加,0-100 cm土层有机碳储量总体变化趋势是先减少后增加最后趋于稳定,为5.93～8.95 kg·m-2,主要富集在0-20 cm；随年限增加,0-100 cm土层SIC的截存能力总体呈略微下降趋势,且其下降主要发生在0-20 cm土层,20 cm以下土层变化不明显。0-100 cm剖面无机碳库贮存量是有机碳库的3.0-4.6倍,表明土壤无机碳库储量在总碳库中占大部分比例。3、通径分析表明,人工植被恢复下土壤性状与土壤有机碳相关性依次为根系生物量土壤pH土壤容重土壤含水量,其中土壤含水量和土壤pH值对SOC含量的影响主要是直接效应,根系生物量对SOC含量的影响主要为正向间接效应,土壤容重对SOC含量影响直接和间接效应相当。其中土壤pH值、土壤容重是SOC含量变化的主导因子,二者共同控制着SOC含量的形成和转化。土壤性质与SIC含量的相关性为：土壤砂粒土壤粘粒土壤含水量,其中土壤砂粒、粘粒是影响SIC含量形成和转化的主要因子。表明短时间人工植被的恢复对SIC含量影响不显著,其含量主要由土壤母质决定。4、通径分析结果表明,天然植被恢复过程中土壤性质与SOC含量的相关性为根系生物量土壤容重土壤电导率土壤含水量,其中根系生物量、土壤含水量对SOC含量主要产生正向直接作用,土壤容重对SOC含量主要是负向直接作用,土壤电导率主要为负向间接作用。其中土壤容重、土壤含水量和根系生物量是影响SOC含量的主导因子,土壤电导率是形成SOC含量的限制因子；土壤性质与SIC含量的相关性为：根系生物量土壤容重土壤含水量粉粒量。其中根系生物量、土壤容重和粉粒对SIC含量主要产生直接效应,土壤含水量对SIC含量主要为负向间接贡献。其中根系生物量、土壤容重是决定SIC含量变化的主导因子,表明天然植被恢复下土壤性质对SIC含量有一定影响。5、不同植被恢复模式下SIC固定效应均高于SOC库,天然植被恢复下SOC固定速率(0.036 g·kg-1.a-1)高于人工植被(0.022 g·kg-1·a-1),恢复年限显著影响着土壤固碳水平。植被恢复过程中SOC含量和SIC含量的形成和周转受到不同土壤性质的影响,不同土壤性质之间存在一定相互关系也会作用于土壤碳库。不同植被恢复下SOC库与SIC库间均呈负相关性,说明二者之间可能存在一定的转化关系,亟需继续研究。
[Abstract]:The restoration and reconstruction of vegetation is an important measure to control soil erosion and improve the ecological environment. Its carbon sequestration benefit is an important basis for measuring the ecological effects of the region. This study uses space instead of time, field investigation and indoor analysis, to sample and determine the typical samples of artificial and natural vegetation restoration in the Loess Plateau. The dynamic change characteristics of soil organic carbon bank and inorganic carbon pool in the process of vegetation restoration and reconstruction are discussed, the evolution relationship between vegetation recovery and soil carbon sequestration is evaluated, and the direct and indirect factors affecting soil organic carbon and inorganic carbon fixation are clarified, aiming at the comprehensive understanding and understanding and the accurate evaluation of the soil restoration of the vegetation on the Loess Plateau. The effect of soil carbon sequestration provides a scientific basis for clarifying the relationship between vegetation restoration and the evolution of soil carbon pool, and providing scientific reference for the restoration and reconstruction of vegetation in the Loess Plateau. The main conclusions are as follows: 1, the effect of soil organic carbon (SOC) fixed on the soil soil of Robinia pseudoacacia with the increase of artificial vegetation restoration years The surface of soil inorganic carbon (soil inorganic carbon, SIC) is not obvious, and the change of soil inorganic carbon (soil inorganic) is not obvious with the period of time. It changes from 16.65 to 20.30kg to m-2, but changes the profile distribution of the accumulation layer; the surface SIC content is the lowest, and the.0-100 cm soil increases with the depth of the soil layer. The reserves of soil inorganic carbon pool are 4.5 to 7.4 times more than that of organic carbon pool. It shows that the contribution of soil inorganic carbon pool to the storage capacity of total carbon storage is most.2. With the increase of natural vegetation restoration years, the overall change trend of organic carbon reserves in 0-100 cm soil layer is first decreasing and then increasing finally to stable, which is 5.93 to 8.95 kg. M-2, mainly enriched in 0-20 cm; With the increase of years, the storage capacity of SIC in the 0-100 cm soil layer decreased slightly, and the decrease mainly occurred in the 0-20 cm soil layer, and the soil layer under 20 cm was not obvious. The storage of inorganic carbon storage in the.0-100 cm section was 3.0-4.6 times of the organic carbon pool, indicating that the reserves of soil inorganic carbon storage in the total carbon pool accounted for the majority of the proportion.3, path analysis showed that The correlation between soil properties and soil organic carbon in artificial vegetation restoration is in turn the soil water content of pH soil bulk density in root biomass. The influence of soil water content and soil pH value on SOC content is mainly direct effect. The effect of root biomass on SOC content is mainly indirect effect, and soil bulk density has direct influence on the content of SOC. The soil pH value and the soil bulk density are the leading factors of the changes in the content of SOC, and the two factors jointly control the formation and transformation of the content of SOC. The correlation between the soil properties and the content of SIC is: soil sand soil clay soil water content, and the soil sand grains and clay particles are the main factors affecting the formation and transformation of SIC content. The restoration of short time artificial vegetation has no significant influence on the content of SIC, the content of which is mainly determined by the soil parent material.4. The result of path analysis shows that the correlation of soil properties and SOC content in the process of natural vegetation restoration is the soil moisture content of soil bulk density soil electrical conductivity in root biomass, and the root biomass and soil water content are the main content of the SOC content. In order to produce direct direct action, soil bulk density is mainly negative to SOC content, and soil conductivity is mainly negative and indirect. Soil bulk density, soil water content and root biomass are the leading factors affecting the content of SOC. Soil conductivity is the limiting factor for the formation of SOC content, and the correlation between soil properties and SIC content is the key factor. The root biomass, the soil bulk density and the powder grain have a direct effect on the content of SIC, and the soil moisture content has a negative indirect contribution to the content of SIC. The root biomass and the soil bulk density are the leading factors to determine the changes in the content of SIC, indicating that the natural vegetation is restored to the soil. The properties of SIC have a certain effect on the content of.5, and the fixed effect of SIC is higher than that of the SOC reservoir under the different vegetation restoration patterns. The fixed rate of SOC (0.036 G. Kg-1.a-1) under the natural vegetation restoration is higher than that of the artificial vegetation (0.022 G. Kg-1. A-1). The restoration years significantly affect the soil carbon sequestration level. The formation and turnover of SOC content and SIC content during the vegetation restoration process are affected by the vegetation restoration. Under the influence of different soil properties, there is a certain relationship between the soil properties and the soil carbon pool. Under the different vegetation restoration, there is a negative correlation between the SOC library and the SIC library, which indicates that there may be a certain transformation relationship between the two, and it is urgent to continue the study.
【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q948;S153

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