国家自然科学基金项目(41630751和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(XK2020063)
Institute of Mountain Hazards and Environment, Chinese Academy of Sciences
The National Natural Science Foundation of China (41630751 and 41877011)；Science and technology research project of Hubei Provincial Department of Education (T2020016 )；Open Foundation by Hubei University of Arts and Science（XK2020063）
除气候、植被类型、微生物活性和径流侵蚀等要素，淋溶过程也是影响土壤碳（C）、氮（N）海拔分布特征的重要因素。通过分析贡嘎山东坡海拔2600 m~3200 m针叶林中土壤C、N的分布特征，对这一因素进行了讨论。结果表明：分解强烈的凋落物层（OH层）的C、N浓度和碳氮比（C:N）随海拔升高有降低趋势。由于凋落物碳（Clit）浓度分别与OH层C、N浓度显著正相关（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浓度及C:N并未发现明显的梯度变化趋势。A层C、N浓度在2781 m样点较低，而B和C层C、N浓度均在2781 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 addition to climate, vegetation types, microbial activities and erosion, leaching is also an important factor influencing the distributions of carbon (C) and nitrogen (N) in soils with elevation. In this study, effects of leaching were discussed to explain the distributions of soil C and N in the coniferous forest along an altitudinal gradient (2600 m~3200 m a.s.l.) on Mt. Gongga. The results showed that the spatial distributions of C, N concentrations and C:N in the humified litter horizon (OH horizon) exhibited a similar decreasing trend with elevation. Since the positive correlation among concentrations of C in litters (Clit), C and N in soils in the OH horizon, the production of Clit was the main factor influencing the altitudinal distributions of C and N in the OH horizon. The obvious altitudinal trend was not observed for C, N concentrations and C:N in the mineral horizons (A, B and C horizon). The contents of C and N in the A horizon were lower in the 2781 m site, while the maximums were in this site for the B and C horizon. The contents of C and N in the rainfall were significantly lower than those in the interflow, which showed the influence of leaching on the spatial distributions of C and N. The results noted above indicated that the leaching process had a non-negligible effect on the spatial distributions of C and N in subalpine coniferous forest soils in southwest China.