论文部分内容阅读
基于芦芽山沿海拔梯度分布的灌丛草地、针阔混交林、寒温性针叶林和亚高山草甸四类典型植被下土壤剖面实测数据,分析了土壤有机碳的垂直分布特征及其与土壤理化因子的关系。结果表明,各植被类型下土壤剖面上层SOC含量最高,最大值往往出现在10—20 cm层,然后向下逐渐减小。土壤有机质含量由剖面上层最大值向下降低过程中,某深度土壤剖面层段有机质含量急剧减小。亚高山草甸剖面这一深度为20 cm,寒温性针叶林剖面为50 cm,针阔混交林剖面为20 cm,灌丛草地剖面为40 cm。0—10 cm层各植被类型间SOC含量差异不显著;10—20 cm层,亚高山草甸和寒温性针叶林SOC含量显著高于其他类型;20—50 cm层,亚高山草甸SOC含量与灌丛草地接近,显著高于针阔混交林,低于寒温性针叶林。植被类型对有机碳剖面分布影响较大。土壤剖面各层有机碳含量与容重呈显著负相关,与土壤含水量和全氮含量呈显著正相关,与土壤pH值呈弱的负相关,与深层黏粒和粉粒含量正相关,在30—50 cm正相关性显著。逐步回归分析结果表明,亚高山草甸SOC含量与土壤总氮含量、含水量和容重显著相关,寒温性针叶林SOC含量与全氮含量显著相关,针阔混交林SOC含量则与总氮含量和土壤容重显著相关,而灌丛草地SOC含量与容重显著相关。在20 cm深度,4种植被土壤有机碳密度差异不显著;50 cm深度亚高山草甸、寒温性针叶林土壤有机碳储量显著高于针阔叶混交林和灌丛草地,50 cm深度土壤有机碳储量与海拔高度呈显著线性正相关(R2=0.299,P=0.01)。
Based on the measured data of soil profiles under four typical vegetation types of shrub land, conifer and broad-leaved mixed forest, cold temperate coniferous forest and subalpine meadow along the altitudinal gradient distribution of Luya Mountain, the vertical distribution characteristics of soil organic carbon And soil physical and chemical factors. The results showed that the SOC content of the upper soil profile was the highest in all vegetation types, and the maximum appeared in 10-20 cm layer and then decreased gradually. During the process of soil organic matter content decreasing downwards from the upper maximum of the profile, the organic matter content in a deep profile section of the soil decreases sharply. The sub-alpine meadow section has a depth of 20 cm, a temperate coniferous forest section of 50 cm, a coniferous-broad mixed forest section of 20 cm and a scrubland section of 40 cm. There was no significant difference in SOC content between 0-10 cm layers. SOC content in 10-20 cm layer, subalpine meadow and cold temperate coniferous forest was significantly higher than that of other types. In 20-50 cm layer, subsoal meadow SOC The content was close to shrub grassland, significantly higher than that of coniferous and broad-leaved mixed forest, lower than that of temperate coniferous forest. Vegetation types have a great influence on the distribution of organic carbon profile. There was a significant negative correlation between organic carbon content and bulk density in soil profile, negative correlation with soil water content and total nitrogen content, weak negative correlation with soil pH, positive correlation with deep clay and silt content, -50 cm positive correlation was significant. The results of stepwise regression analysis showed that SOC content in subalpine meadow was significantly correlated with soil total nitrogen content, water content and bulk density. SOC content in cold-temperate coniferous forest was significantly correlated with total nitrogen content, while SOC content in mixed coniferous-broad-leaved forest with total nitrogen There was a significant correlation between soil bulk density and SOC content, while SOC content in shrub grassland was significantly correlated with bulk density. At the depth of 20 cm, there was no significant difference in soil organic carbon density among the four vegetation types. The soil organic carbon storage in sub-alpine meadow and cold temperate coniferous forest at 50 cm depth was significantly higher than that in coniferous and broad-leaved mixed forest and shrub grassland. There was a significant linear positive correlation between soil organic carbon storage and altitude (R2 = 0.299, P = 0.01).