| 引用本文: | 曹世宁,罗雨甜,余博航,等.川西王朗地区土壤含水率和碳库沿海拔梯度的变化规律及相互关系[J].灌溉排水学报,2025,44(8):148-156. |
| CAO Shining,LUO Yutian,YU Bohang,et al.川西王朗地区土壤含水率和碳库沿海拔梯度的变化规律及相互关系[J].灌溉排水学报,2025,44(8):148-156. |
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| 摘要: |
| 【目的】明确王朗地区土壤含水率、有机碳量、无机碳量及总碳量沿垂直分布和海拔梯度的变化特征，并探讨其相互关系及影响因子的驱动机制。【方法】采集王朗地区不同海拔0~15 cm表层土壤、15~30 cm亚层土壤样本，测定土壤有机碳量、无机碳量、总碳量及土壤含水率，分别采用Mann-Whitney U检验与线性回归分析，研究土壤碳组分和土壤含水率的垂直分布特征及其与海拔的相关性，并探讨各指标之间的耦合关系。【结果】在表层、亚层土壤中，有机碳量和无机碳量对总碳量的相对贡献存在差异，其中有机碳量占主导地位；此外，总碳量与有机碳量的相关性强于其与无机碳量的相关性（表层有机碳R2=0.998，表层无机碳R2=0.566，P＜0.001；亚层有机碳R2=0.995，亚层无机碳R2=0.551，P＜0.001），这表明有机碳量对总碳量影响更大，且表层土壤总碳量、有机碳量、无机碳量和土壤含水率均显著高于亚层土壤（P＜0.05）。表层土壤有机碳量、无机碳量、总碳量及土壤含水率均与海拔显著正相关（P＜0.001）；亚层土壤有机碳量、无机碳量、总碳量及土壤含水率与海拔显著正相关（P＜0.05）。表层土壤无机碳量与土壤含水率的正相关性略强于有机碳量（R2分别为0.421、0.403，P＜0.001）；而亚层土壤有机碳量与土壤含水率的正相关性更为显著（R2=0.611，P＜0.001），高于无机碳量与土壤含水率的相关性（R2=0.375，P＜0.001）。表层、亚层土壤中，无机碳量与有机碳量均显著正相关（P＜0.001），可能存在一定的生物地球化学耦合机制。【结论】王朗地区的土壤碳库主要由有机碳贡献占主导地位，并且各碳组分及土壤含水率均呈显著的单调递增的海拔梯度变化特征。然而，不同碳组分的变化规律存在一定差异。同时，土壤含水率对有机碳量的影响显著强于对无机碳量的作用，表明有机碳受水分条件的驱动更敏感。 |
| 关键词: 海拔；土壤含水率；土壤有机碳量；土壤无机碳量 |
| DOI：10.13522/j.cnki.ggps.2025020 |
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| Variation and coupling of soil moisture and soil carbon along an elevation gradient in the region of Western Sichuan, China |
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CAO Shining, LUO Yutian, YU Bohang, ZHAO Yuze, WANG Jianming
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1. School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China;
2. Sichuan Wanglang National Nature Reserve Administration Bureau, Pingwu 622550, China
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| Abstract: |
| 【Objective】Soil carbon and soil moisture are two critical factor influencing ecosystem stability and carbon cycling. This paper studies the variations in soil moisture, organic carbon (SOC) and inorganic carbon (SIC) in soil profiles in the region of Wanglang in Western Sichuan, as well as their interrelationships and underlying mechanisms.【Method】 Soil samples were collected from the 0-15 cm and 15-30 cm soil layers in different locations with an altitude gradient across the region. SOC, SIC, total carbon and soil moisture in the samples were measured. Their spatial distribution pattern and correlation with altitude were analyzed using the Mann-Whitney U tests and the linear regression.【Result】Organic carbon contributed more significantly to total carbon than inorganic carbon in both soil layers. Total carbon was strongly correlated with SOC, with R2=0.998 for the topsoil surface and 0.995 for the subsoil (P＜0.001), but less so with SIC, with R2=0.566 for the topsoil and 0.551 for the subsoil (P＜0.001). SOC, SIC, total carbon and soil moisture were significantly higher in the topsoil than in the subsoil (P＜0.05). Both carbon and soil moisture showed positive correlations with altitude (P＜0.001 for the topsoil and P＜0.05 for the subsoil). In the topsoil, SIC was correlated to soil moisture more significantly (R2=0.421) than SOC (R2=0.403), whereas in the subsoil, SOC showed a stronger correlation with soil moisture (R2=0.611) than SIC (R2=0.375). A positive correlation between SOC and SIC was observed in both soil layers (P＜0.001), suggesting a biogeochemical coupling between them.【Conclusion】Soil carbon in the study area is predominantly composed of organic carbon. Both soil carbon content and soil moisture increase with elevation, though at varying rates. Soil moisture has a stronger influence on SOC than on SIC, indicating greater sensitivity of organic carbon to soil moisture changes. |
| Key words: altitude; soil moisture; soil organic carbon; soil inorganic carbon |
