国家自然科学基金项目(41630751； 41877011); 湖北省高等学校优秀中青年科技创新团队计划项目(T2020016); 湖北文理学院学科开放基金项目(XK2020063)
为揭示淋溶过程在山地养分循环中的重要作用，研究了贡嘎山东坡海拔2 600~3 200 m针叶林土壤碳（C）、氮（N）的海拔分布特征，分析了不同海拔4个样点的针叶林土壤C、N含量及碳氮比（C/N），并结合其他土壤物理、化学和生物指标探讨了淋溶过程对土壤C、N海拔分布特征的影响。结果显示：分解强烈的凋落物层（OH层）的C、N含量和碳氮比（C/N）随海拔升高有降低趋势。由于凋落物碳（Clit）含量分别与OH层C、N含量显著正相关（P<0.05），因此，OH层C、N海拔分布特征主要由Clit输入量控制。与OH层相比，矿质土层（A、B和C层）中C、N含量及C/N并未发现明显的梯度变化趋势。A层C、N含量在2 781 m样点较低，而B和C层C、N含量均在2 781 m样点最高。天然降雨中C、N含量明显低于壤中流中C、N含量，展现了淋溶作用对C、N空间分布的影响。上述结果表明，淋溶过程对西南亚高山针叶林土壤C、N空间分布格局具有不可忽略的影响。
In order to reveal the importance of leaching on mountainous nutrients cycling,the characteristics of altitude distribution of soil C and N in the coniferous forest at an altitude of 2 600-3 200 m on the eastern slope of the Gongga mountain were studied. The soil C,N content and C/N of the conifers at 4 sampling points at different altitudes were analyzed. Combined with other soil physical,chemical and biological indicators,the effects of the leaching process on the characteristics of altitudinal distribution of soil C and N were explored. The results showed that the spatial distributions of C,N contents and C/N in the humified litter horizon (OH horizon) exhibited a similar decreasing trend with the increase of altitude. Since the content of C in litters (Clit) was positively correlated with soil C and N in the OH horizon（P<0.05）,the production of Clit was the main factor affecting the altitudinal distributions of soil C and N in the OH horizon. The obvious altitudinal trend was not observed for soil C,N contents and C/N in the mineral horizons (A,B and C horizon). The contents of soil C and N in the A horizon were lower than those in the 2 781 m site,while the maximums were for the B and C horizon in this site. The contents of soil C and N in the rainfall were significantly lower than those in the interflow,which showed the effects of leaching on the spatial distributions of soil C and N. It is indicated that the effects of leaching process on the spatial distributions of soil C and N in subalpine coniferous forest in Southwest Asia can not be ignored.