张广才岭西坡地形因子和保护机制对土壤有机碳积累的相对影响

发布时间：2018-06-24 01:09

本文选题：土壤有机碳 + 有机碳组分　；参考：《东北林业大学》2015年硕士论文

【摘要】：本研究在张广才岭西部典型低山丘陵次生林区,按坡位、坡向差异对等设置36块样地,采集lm剖面深度范围内不同发生层土样。分析土壤有机碳及其在各组分(团聚体密度/粒径组分)中分配,探讨了地形因子(坡位、坡向、坡度)对土壤有机碳含量、有机碳密度的影响和土壤有机碳与物理保护因子(粘粒、团聚体)的关系,揭示土壤有机碳的物理保护及稳定机制,并借助逐步回归分析量化各因子对土壤有机碳密度变异影响的相对大小。结果表明：本区土壤1m剖面有机碳密度范围为8.9～31.3kg/m2,具有较大的空间变异性,土壤有机碳的表聚特征明显,平均而言A层集中了全剖面总有机碳的55.2%。坡位和坡向显著影响本区土壤有机碳的分布：下坡A层有机碳密度是上坡的1.83倍,其1m剖面有机碳密度是上坡的1.67倍：阴坡A层有机碳密度是阳坡的1.37倍,其lm剖面有机碳密度是阳坡的1.17倍。不过,在所调查的范围内坡度对上、下坡土壤有机碳含量和密度均无显著影响。本区土壤有机碳与粘粒、团聚体的相关格局较复杂,但排除坡位和坡积埋藏层等因子影响后,土壤有机碳含量、有机碳密度与粘粒、团聚体均不相关,因此粘粒保护和团聚体保护并非本区土壤有机碳积累的控制因子。通过对土壤有机碳在各组分(团聚体密度／粒径组分)中分配进一步分析,再一次证明土壤本身的物理保护(粘粉粒保护、团聚体保护、总物理保护)作用不是本区土壤总有机碳积累(差异)的控制因素。逐步回归显示,坡位是本区土壤有机碳数量分异的主控因子,可独立解释A层有机碳密度空间变异的57.5%、lm剖面有机碳空间变异的63.2%；粘粒和团聚体作为公认的土壤有机碳物理保护因子,却因贡献微小而在逐步回归过程中被剔除。本研究结果为土壤有机碳物理保护及稳定机制的研究提供了科学依据,同时为区域森林土壤碳储量准确估算和碳汇林立地选择提供参考。
[Abstract]:In this study, 36 sample plots were set up according to slope position and slope direction difference in typical low hill secondary forest area in the west of Zhangguangcailing. Soil samples of different layers were collected in depth range of LM profile. Soil organic carbon (SOC) and its distribution in each component (aggregate density / particle size fraction) were analyzed, and the effects of topographic factors (slope position, slope direction, slope) on soil organic carbon content were discussed. The effects of organic carbon density and the relationship between soil organic carbon and physical protection factors (clay, aggregates) reveal the physical protection and stabilization mechanism of soil organic carbon. The effects of various factors on soil organic carbon density variability were quantified by stepwise regression analysis. The results showed that the density range of organic carbon in soil 1m profile was 8.9 ~ 31.3 kg / m ~ (-2), which had great spatial variability, and the apparent accumulation of soil organic carbon was obvious. On average, A layer concentrated 55.2% of the total organic carbon in the whole section. The distribution of soil organic carbon was significantly affected by slope position and direction: the organic carbon density of A layer was 1.83 times higher than that of upper slope, the organic carbon density of 1 m profile was 1.67 times higher than that of upper slope, and the organic carbon density of A layer in shady slope was 1.37 times of that of sunny slope. The organic carbon density of Lm profile is 1.17 times of that of sunny slope. However, the soil organic carbon content and density were not significantly affected by the slope. The correlation pattern of soil organic carbon, clay and aggregate is more complex, but the soil organic carbon content and organic carbon density are not related to clay and aggregate after the factors such as slope position and slope buried layer are excluded. Therefore, clay protection and aggregate protection are not the controlling factors of soil organic carbon accumulation in this area. Through the further analysis of the distribution of soil organic carbon in each component (aggregate density / particle size component), it is proved once again that the physical protection of soil (clay particle protection, aggregate protection), Total physical protection is not the controlling factor of soil total organic carbon accumulation (difference). The stepwise regression analysis showed that the slope position was the main factor of soil organic carbon quantity differentiation in this area, which could independently explain the spatial variation of organic carbon in the 57.5lm profile of layer A, which was 63.2% of the spatial variation of organic carbon. Clay and aggregates are recognized as physical protection factors of soil organic carbon, but they are eliminated in the process of stepwise regression because of their small contribution. The results provide a scientific basis for the study of the physical protection and stabilization mechanism of soil organic carbon, and provide a reference for the accurate estimation of soil carbon storage and the selection of carbon sequestration sites.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S153.6

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