摘要
选取贵州省中西部普定县城周边具有不同岩性(碎屑岩和碳酸盐岩)的2个坡地的土壤剖面为研究对象,采集了不同坡地位置的砂岩黄壤剖面和黄色石灰土剖面,分析了土壤pH值、C/N值、土壤有机碳(SOC)含量以及有机碳同位素组成,探讨了黄壤与石灰土δ13CSOC值组成差异和SOC含量沿剖面以及在不同坡地位置的分布特征。结果表明:砂岩黄壤和黄色石灰土的有机碳含量变化范围分别为3.1～79.7和8.2～73.3 g·kg-1;沿坡面顶端到底端,2种土壤类型SOC含量均呈现出坡脚>坡顶>坡腰;除砂岩黄壤坡顶剖面的个别层位外,2类土壤剖面SOC含量均随剖面深度的增加而降低;砂岩黄壤和石灰土剖面δ13CSOC值的变化范围分别为-25.4‰～-20.7‰和-23.2‰～-18.8‰;除黄色石灰土坡腰剖面外,其余土壤剖面的δ13CSOC值均表现为随剖面表层至20～40 cm升高,然后随深度增加而降低,最后趋于稳定的特征;2类坡地土壤SOC含量以及δ13CSOC值的变化反映了不同类型植被残体的输入以及在土壤中的降解累积特征,有助于了解坡地堆积侵蚀以及成土过程对SOC循环的影响。
Abstract： Soil samples were collected from two types （elastic rock and carbonate rock） around the Puding of slope soil profiles with different lithology County of Guizhou Province, and their pH values, C/N ratios, organic carbon （SOC） contents, and SOC isotope compositions were ana- lyzed, aimed to approach the distribution patterns of SOC and 813Csoc in the two types of the soil profiles at different slope positions. The results showed that the SOC contents in the profiles of sandstone yellow soil and limestone yellow soil ranged from 3.1-79.7 g ~ kg-1 and 8.2-73.3 g ~ kg-1 , respectively. From the top to the bottom of the slopes, the SOC contents in the two soils showed the same distribution pattern, i. e. , slope bottom 〉 slope top 〉 slope waist. Across each soil profile, the SOC content decreased as a function of soil depth, except that of the sandstone yellow soil profile on the slope top. The ~13 Csoc values in the profiles of sandstone yellow soil and limestone yellow soil varied in the range of -25.4%e to -20.7%o and -23.2%e to -18.8%e, re- spectively. Except for the limestone yellow soil profile on the slope waist, the δ13 Csoc values in the other soil profiles increased firstly from the surface layer to the 20-40 cm depth, then decreased as a function of soil depth, and finally kept stable at the base of the soil profiles. The vailations of the SOC contents and the δ13 Csoc values as a function of soil depth could be due to the in- put of plant residue and its degradation and accumulation in soil. This study provided insights to the slope soil erosion and the effects of pedogenic process on the SOC circulation of slope soils.
出处
《生态学杂志》
CAS
CSCD
北大核心
2013年第9期2362-2367,共6页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41073099和41203090)
中国科学院知识创新工程项目(KZCX2-EW-102和KZCX2-YW-137)资助
关键词
喀斯特地区
黄壤
石灰土
土壤有机碳
稳定碳同位素
karst area
yellow soil
limestone soil
soil organic carbon
stable carbon isotope
