大围山不同海拔森林土壤有机碳垂直分布特征

The Vertical Distribution Characteristics of Soil Organic Carbon in Different Altitude of Dawei Mountain

为研究亚热带地区典型森林土壤有机碳沿海拔梯度的分布特征,于2013年10月在大围山国家森林公园选择4个不同海拔的采样点,采集0-100cm剖面土样,分析土壤有机碳和土壤腐殖酸、胡敏酸(HA)、富里酸(FA)含量,研究其垂直分布特征和影响因素。结果表明,(1)土壤有机碳含量与海拔高度密切相关。高海拔剖面土壤有机碳明显高于低海拔剖面,4个采样点剖面有机碳平均含量表现为(18.84±14.42)g/kg(海拔1 465m)>(13.94±6.05)g/kg(海拔1 402m)>(11.95±9.20)g/kg(海拔1 002m)>(11.05±7.97)g/kg(海拔800m)。(2)土壤有机碳、腐殖酸含量随着土壤剖面深度的增加而递减,而腐殖酸占有机碳的比例会有所增加,胡敏酸和富里酸比值(HA/FA)随着土壤剖面深度的增加呈降低的趋势。(3)土壤有机碳含量与土壤容重、全氮、全磷均存在极显著相关关系(P<0.01),与毛管孔隙度和土壤中粉粒含量存在显著正相关关系(P<0.05),腐殖酸与土壤pH值存在显著的负相关(P<0.05)。总之,大围山森林土壤有机碳沿海拔梯度变化趋势明显,土壤有机碳含量随海拔升高而增加,随土壤剖面深度增加而显著降低;土壤腐殖酸含量随土壤剖面深度的增加而显著降低,占有机碳比例却表现出一定的增长趋势,但其与海拔高度并没有显著关系。

To clarify altitudinal gradient of subtropical forest soil organic carbon（SOC）in Dawei Mountain,four different altitudes sampling points were researched on each layer（0-100cm）in October 2013,determined the SOC and humus component content,studied the composition and vertical distribution.The results showed that（1）SOC content was closely related to altitude.SOC contents of high altitude profiles were significantly higher than that in low altitude.The performance of the average SOC content of whole cross-section was（18.84±14.42）g/kg（altitude1 465m）〉（13.94±6.05）g/kg（altitude 1 402m）〉（11.95±9.20）g/kg（altitude 1 002m）〉（11.05±7.97）g/kg（altitude 800 m）.（2）SOC and humic acid content were decreased with increasing of soil depth,while the percentage of Humic acid and SOC were increased,HA/FA values was decreased with increasing of soil depth.（3）SOC and soil bulk density,total nitrogen and total phosphorus were highly significant correlated（P〈0.01）.SOC showed significantly positive correlation with soil capillary porosity and silt content in soil（P〈0.05）,while a significant negative correlation between humic acid content and soil pH value（P〈0.05）.In conclusion,SOC content was increased with altitude obviously in Dawei Mountain,but significantly decreased with soil depth.Humic acid content also decreased with soil depth significantly,while the percentage of humic acid and SOC shown a level of growth,but it was not associated with the altitude significantly.