Wetlands are the largest natural source of methane (CH₄), but spatial variability in fluxes complicates prediction, budgeting, and mitigation efforts. Despite the many environmental factors identified as CH₄ drivers, the overall influence of wetland spatial heterogeneity on CH₄ fluxes remains unclear. We identified five dominant patch types—submersed aquatic vegetation (SAV), emergent forbs, sedges/rushes, grasses, and open water—within a freshwater wetland in Maryland, USA, and measured CH₄ fluxes using a combined chamber and eddy covariance approach from June to September 2021. Because patch types integrate co-occurring environmental factors, we hypothesized that CH₄ flux is best characterized at the patch scale. Chamber measurements from representative patches showed distinct CH₄ signals; fluxes from grasses and sedges/rushes were highest, while fluxes from SAV and forbs were lower but skewed, suggesting episodic emission pulses. Open water had the lowest fluxes. Differences between patches were consistent over time, and spatial variability was greater between patches than within them, highlighting patches as key drivers of flux variability. By combining chamber fluxes with eddy covariance data in a Bayesian framework, we provide evidence that patch-type fluxes scale over space and time. Understanding spatial heterogeneity is essential for quantifying wetland contributions to global biogeochemical cycles and predicting the impacts of environmental change on wetland ecosystem processes. Our study demonstrates the importance of vegetation patch types in structuring spatial variability and supports a patch-explicit representation to reduce uncertainty in wetland CH₄ fluxes.

湿地是甲烷 （CH₄） 的最大天然来源，但通量的空间可变性使预测、预算和缓解工作变得复杂。尽管许多环境因素被确定为 CH₄ 驱动因素，但湿地空间异质性对 CH₄ 通量的总体影响仍不清楚。我们在美国马里兰州的淡水湿地中确定了五种主要斑块类型——淹没水生植被 （SAV）、新兴杂草、莎草/灯心草、草和开阔水域，并使用 2021 年 6 月至 2021 年 9 月的室和涡度相关相结合方法测量了 CH₄ 通量。由于贴片类型整合了共存的环境因素，我们假设 CH₄ 通量在贴片尺度上表征最好。来自代表性斑块的腔室测量显示明显的 CH₄ 信号;来自草和莎草/灯心草的通量最高，而来自 SAV 和杂草的通量较低但偏斜，表明存在偶发性发射脉冲。开阔水域的通量最低。斑块之间的差异随着时间的推移是一致的，斑块之间的空间变异性大于斑块内部的空间变异性，突出了斑块是通量变异性的关键驱动因素。通过在贝叶斯框架中将腔室通量与涡度协方差数据相结合，我们提供了斑块型通量随空间和时间缩放的证据。了解空间异质性对于量化湿地对全球生物地球化学循环的贡献和预测环境变化对湿地生态系统过程的影响至关重要。我们的研究证明了植被斑块类型在构建空间变异性中的重要性，并支持斑块显式表示以减少湿地 CH₄ 通量的不确定性。