| 重庆主城区马尾松林土壤有机碳组分特征及其影响因素 |
| 摘要点击 445 全文点击 30 投稿时间：2025-01-06 修订日期：2025-03-18 |
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| 中文关键词 马尾松林 土壤有机碳（SOC） 颗粒态有机碳（POC） 矿物结合态有机碳（MAOC） 土壤总氮 |
| 英文关键词 Pinus massoniana forest soil organic carbon（SOC） particulate organic carbon（POC） mineral-associated organic carbon（MAOC） soil total nitrogen |
| DOI 10.13227/j.hjkx.20260233 |
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| 中文摘要 |
| 马尾松林是三峡库区最常见的植被类型，其土壤碳库稳定性对区域碳平衡具有重要调控作用. 为分析重庆主城区马尾对不同土壤有机碳组分特征及其影响因素，以重庆主城区周边22块代表性马尾松林样地为研究对象，测定马尾松林表层土壤（0~10 cm）颗粒态有机碳和矿物结合态有机碳的含量，结合林分特征与土壤理化指标解析其驱动机制. 结果表明，研究区域马尾松林表层土壤ω（有机碳）为9.0~18.6 g·kg-1，总体上含量较低，且在空间上有较大的变异性；研究区域马尾松林土壤有机碳主要以较稳定的矿物结合形式赋存，MAOC平均占比为75.2%，颗粒态赋存有机碳的碳氮比显著高于以矿物结合态赋存的有机碳（P<0.01）. 协变分析表明，颗粒态有机碳与矿物结合态有机碳含量呈显著正相关关系（P<0.05），且均与总有机碳呈显著正相关（P<0.01），二者变化对土壤总有机碳变化贡献程度接近一致. 一般线性回归分析和冗余分析显示， 林龄（P<0.05）和土壤总氮含量（P<0.01）均与矿物结合态有机碳含量呈显著的正相关关系，表明林龄和土壤氮可获得性是影响该区域马尾松林稳定土壤有机碳积累的关键因素. 变差分解说明土壤理化因子相较林分特征对土壤有机碳组分的影响更强烈，土壤总氮和碳氮比是最重要的影响因素. |
| 英文摘要 |
| Pinus massoniana forests are the predominant vegetation in the Three Gorges Reservoir Area. The stability of its soil carbon pool plays an important role in regulating the regional carbon balance. In order to analyze the characterization of different soil organic carbon fractions and their influencing factors by P. massoniana forests in the main urban area of Chongqing， this study analyzed characteristics of soil organic carbon fractions and their drivers in 22 representative P. massoniana forest plots in the area. Surface soil （0-10 cm）， particulate organic carbon （POC）， and mineral-associated organic carbon （MAOC） contents were measured， with forest stand characteristics and soil physicochemical properties examined to identify driving mechanisms. The results showed that surface soil organic carbon content ranged from 9.0 to 18.6 g·kg-1， exhibiting low overall levels and significant spatial variability. Soil organic carbon primarily existed in stable mineral-associated forms （MAOC averaged 75.2%）， while POC displayed a significantly higher C/N ratio than MAOC （P<0.01）. Covariance analysis revealed positive correlations between POC and MAOC （P<0.05） and between both fractions and total soil organic carbon （P<0.01）， with their contributions to total soil organic carbon variations being nearly equivalent. General linear regression and redundancy analysis demonstrated that stand age （P<0.05） and total soil nitrogen （P<0.01） positively influenced MAOC content， indicating their critical roles in stable soil organic carbon accumulation. Variation partitioning highlighted stronger effects of soil physicochemical properties （notably total nitrogen and C/N ratio） on soil organic carbon fractions compared to stand characteristics. These findings suggest that stand age and soil nitrogen availability were key determinants of stable soil organic carbon sequestration in P. massoniana forests， with soil nitrogen dynamics dominating soil organic carbon fraction patterns. |
