Peatlands are recognized as crucial greenhouse gas sources and sinks and have been extensively studied. Their emissions exhibit high spatial heterogeneity when measured on site using flux chambers. However, the mechanism by which this spatial variability behaves on a very fine scale remains unclear. This study investigates the fine-scale spatial variability of greenhouse gas emissions from a subantarctic Sphagnum peatland bog. Using a recently developed skirt chamber, methane emissions and ecosystem respiration (as carbon dioxide) were measured at a submeter scale resolution, at five specific 3 × 3 m plots, which were examined across the site throughout a single campaign during the Austral summer season. The results indicated that methane fluxes were significantly less homogeneously distributed compared with ecosystem respiration. Furthermore, we established that the spatial variation scale, i.e., the minimum spatial domain over which notable changes in methane emissions and ecosystem respiration occur, was <0.56 m². Factors such as ground height relative to the water table and vegetation coverage were analyzed. It was observed that Tetroncium magellanicum exhibited a notable correlation with higher methane fluxes, likely because of the aerenchymatous nature of this species, facilitating gas transport. This study advances understanding of gas exchange patterns in peatlands but also emphasizes the need for further efforts for characterizing spatial dynamics at a very fine scale for precise greenhouse gas budget assessment.

中文翻译：

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亚南极泥炭地沼泽温室气体排放的细尺度空间变化

泥炭地被认为是重要的温室气体源和汇，并已得到广泛研究。当使用通量室进行现场测量时，它们的排放表现出高度的空间异质性。然而，这种空间变异在非常精细的尺度上表现的机制仍不清楚。本研究调查了亚南极泥炭地沼泽温室气体排放的精细尺度空间变化。使用最近开发的裙室，在五个特定的 3 × 3 m 地块上以亚米级分辨率测量甲烷排放和生态系统呼吸（作为二氧化碳），并在澳大利亚夏季的一次活动中对整个场地进行了检查。结果表明，与生态系统呼吸相比，甲烷通量的分布明显不均匀。此外，我们还确定了空间变化尺度，即甲烷排放和生态系统呼吸发生显着变化的最小空间范围<0.56 m ²。分析了相对于地下水位的地面高度和植被覆盖度等因素。据观察，Tetroncium magellanicum表现出与较高甲烷通量的显着相关性，可能是因为该物种的通气性质，促进了气体运输。这项研究增进了对泥炭地气体交换模式的理解，但也强调需要进一步努力在非常精细的尺度上描述空间动态，以进行精确的温室气体预算评估。