【摘要】 滨海湿地具有强大的碳捕获和储存能力，对缓解气候变暖具有重要作用，其中植被类型是影响其碳储量的重要因素。本研究测定了黄河口湿地三种典型植被（芦苇、芦苇-柽柳、翅碱蓬）表层土壤有机碳（soil organic carbon, SOC）、木质素、稳定碳同位素(δ¹³C)、粒度以及铁元素含量，并对有机碳含量、来源及降解特征进行了分析。结果表明，黄河口湿地三种植被生境SOC含量为0.34%～1.85%,芦苇生境最高，平均值为0.94%,SOC含量受植被类型和黏土含量的共同影响。通过三端元蒙特卡罗模型计算发现，三种植被生境土壤有机碳以陆源（47.7%±13.2%）和植物源（36.3%±15.0%）为主，海源（16.0%±14.2%）比例较低（翅碱蓬>芦苇-柽柳>芦苇）。三种植被生境土壤木质素都表现为木本类和草本类组织的混合或单一来源，指示芦苇和翅碱蓬生境中部分土壤有机碳来自于上游黄土高原。土壤中的铁氧化物和水分可能因其对有机碳的保护和对微生物有氧呼吸的抑制作用，降低木质素的降解程度。该研究表明，土壤有机碳在不同类型植被中的分布、来源以及降解特征存在明显的差异。更多还原

【Abstract】 Coastal wetlands have a strong capacity for carbon capture and storage, playing a significant role in mitigating climate warming. Vegetation type is an important factor influencing the carbon storage. In this study, we measured the soil organic carbon（SOC）, lignin, stable carbon isotope(δ¹³C), grain size, and iron content in the surface soil of three typical vegetation habitats（Phragmites australis, Phragmites australis-Tamarix chinensis, and Suaeda salsa） in the Yellow River Estuary wetland, and analyzed the content, source, and degradation characteristics of organic carbon. The results showed that the SOC content in the three vegetation habitats of the Yellow River estuary wetland ranged from 0.34% to 1.85%, with the highest in P. australis, which had an average value of 0.94%. The SOC content was jointly affected by vegetation type and clay content. The three-end-member Monte Carlo model calculation found that the soil organic carbon in the three vegetation habitats was mainly from terrestrial（47.7%±13.2%） and plant sources（36.3%±15.0%）, with a relatively low marine source（16.0%±14.2%）（S. salsa>P. australis-T. chinensis>P. australis）. The soil lignin in the three vegetation habitats all showed a mixture or single source of woody and herbaceous tissues, indicating that part of the soil organic carbon in the P. australis and S. salsa habitats originated from the upstream Loess Plateau. Iron oxides and water in the soil might reduce the degradation of lignin due to their protective effect on organic carbon and their inhibitory effect on aerobic respiration of microorganisms. This study showed that there were significant differences in the distribution, source, and degradation characteristics of soil organic carbon among different vegetation habitats.更多还原