武夷山不同海拔植被土壤易氧化碳

Soil readily oxidizable carbon along an elevation gradient of Wuyi Mountains in southeastern China

土壤有机质的短暂波动主要发生在易氧化部分，而易氧化碳作为土壤有机碳的敏感因子，可以指示土壤有机质的早期变化。采用高锰酸钾氧化法，分析了福建武夷山自然保护区不同海拔高度具有代表性的中亚热带常绿阔叶林（200～1000m）、针叶林（1350～1750m）、亚高山矮林（1750～1900m）以及高山草甸（1700～2158m）土壤中易氧化碳的变化特征，分析其与微生物量碳、土壤总有机碳、土壤含水量、全氮之间的关系。结果表明：不同群落土壤中的易氧化碳含量随海拔上升而增加，随土层深度的增加而减少；易氧化碳和土壤总有机碳、微生物量碳、土壤湿度、全氮间呈极显著的相关；土壤易氧化碳占总有机碳比例为8．69％～14．73％，是微生物量碳占总有机碳比例的3．32～11．41倍；沿海拔梯度，易氧化碳含量受到土壤总有机碳、土壤湿度和温度的显著影响。

The short-term fluctuation of soil organic matter mainly takes place in its labile fraction, and readily oxidizable carbon （ ROC）, a sensitive factor of soil active organic carbon, is always considered as one of the indices in predicting the early change of soil organic matter. By using potassium permanganate oxidation, the change characteristics of soil ROC in evergreen broadleaf forest （200-1 000 m above sea level）, coniferous forest （1 350-1 750 m above sea level）, dwarf forest （ 1 750-1 900 m above sea level）, and alpine meadow （ 1 700-2 158m above sea level） in Wuyi Mountains Natural Reserve in Fujian of China was studied, with the relationships of soil ROC with soil microbial biomass carbon （ MBC）, total organic carbon （ TOC）, total nitrogen （TN）, and moisture content analyzed. The results showed that the content of soil ROC increased with elevation, but decreased with soil depth. Soil ROC had positive correlations with soil MBC, TOC, TN, and moisture content, and the percentage of soil ROC to soil TOC （8.69%-14.73%） was 3.32-11.41 times higher than that of soil MBC to soil TOC. The soil ROC along the elevation gradient was significantly affected by soil TOC, moisture, and temperature.