國家自然科學基金項目(41630751和41877011); 湖北省高等學校優秀中青年科技創新團隊計劃項目(T2020016); 湖北文理學院學科開放基金(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）
除氣候、植被類型、微生物活性和徑流侵蝕等要素，淋溶過程也是影響土壤碳（C）、氮（N）海拔分布特征的重要因素。通過分析貢嘎山東坡海拔2600 m~3200 m針葉林中土壤C、N的分布特征，對這一因素進行了討論。結果表明：分解強烈的凋落物層（OH層）的C、N濃度和碳氮比（C:N）隨海拔升高有降低趨勢。由于凋落物碳（Clit）濃度分別與OH層C、N濃度顯著正相關（p < 0.05），因此，OH層C、N海拔分布特征主要由Clit輸入量控制。與OH層相比，礦質土層（A、B和C層）中C、N濃度及C:N并未發現明顯的梯度變化趨勢。A層C、N濃度在2781 m樣點較低，而B和C層C、N濃度均在2781 m樣點最高。天然降雨中C、N含量明顯低于壤中流中C、N含量，展現了淋溶作用對C、N空間分布的影響。上述結果表明，淋溶過程對西南亞高山針葉林土壤C、N空間分布格局具有不可忽略的影響。
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.