Southern California coastal wetlands are heavily impacted by urbanization and are under increased inundation stress due to sea level rise (SLR). This study evaluated the impacts of inundation on decomposition rates and sediment decomposer communities (invertebrates, fungi, and bacteria) by manipulating inundation using a marsh organ. Under increased inundation, invertebrate diversity decreased, and plant litter decomposition was reduced by excluding fungi and invertebrates from substrates using litter bags, indicating that all three decomposer guilds are important. This study showed significant impacts of increased inundation on bacterial, fungal and invertebrate community structure and diversity, yet only modest effects on sulfate reduction and decomposition rates, suggesting a degree of resilience or functional redundancy in the decomposer community. While the marsh organ successfully simulated increased inundation, it also created experimental ‘bottle effects’ that may have obscured inundation treatment effects and altered communities from the natural marsh. In our study, invertebrates were most sensitive to inundation, while bacteria appeared to be more resistant. This has implications for how decomposition and associated biogeochemical and ecological processes might change in the face of increased inundation due to SLR and suggests that marsh organs may be less suitable for investigating microbial communities compared with plants.

南加州沿海湿地受到城市化的严重影响，并且由于海平面上升（SLR）而遭受淹没压力的增加。这项研究通过使用沼泽器官操纵淹没来评估淹没对分解速率和沉积物分解物群落（无脊椎动物，真菌和细菌）的影响。在淹没增加的情况下，通过使用垃圾袋将真菌和无脊椎动物从基质中排除，无脊椎动物的多样性降低了，并且减少了植物凋落物的分解，这表明这三个分解者协会都很重要。这项研究表明，淹没增加对细菌，真菌和无脊椎动物群落结构和多样性具有重大影响，但对硫酸盐还原和分解速率的影响却不大，表明分解器社区具有一定程度的弹性或功能冗余。虽然沼泽器官成功地模拟了淹没的增加，但它也创造了实验性的“瓶效应”，可能会掩盖淹没处理的作用并改变自然沼泽的群落。在我们的研究中，无脊椎动物对淹没最敏感，而细菌似乎更具抵抗力。面对由于单反导致的淹没增加，分解以及相关的生物地球化学和生态过程可能如何发生变化，这暗示着沼泽植物可能比植物更不适合研究微生物群落。它还创造了实验性的“药瓶效应”，可能掩盖了淹没处理的效果并改变了天然沼泽的群落。在我们的研究中，无脊椎动物对淹没最敏感，而细菌似乎更具抵抗力。面对由于单反导致的淹没增加，分解以及相关的生物地球化学和生态过程可能如何发生变化，这暗示着沼泽植物可能比植物更不适合研究微生物群落。它还创造了实验性的“药瓶效应”，可能掩盖了淹没处理的效果并改变了天然沼泽的群落。在我们的研究中，无脊椎动物对淹没最敏感，而细菌似乎更具抵抗力。面对由于单反导致的淹没增加，分解以及相关的生物地球化学和生态过程可能如何发生变化，这暗示着沼泽植物可能比植物更不适合研究微生物群落。