Drained agricultural peatlands occupy only 1% of agricultural land but are estimated to be responsible for approximately one third of global cropland greenhouse gas emissions. However, recent studies show that greenhouse gases fluxes from agricultural peatlands can vary by orders of magnitude over time. The relationship between these hot moments (individual fluxes with disproportionate impact on annual budgets) of greenhouse gas emissions and individual chamber locations (i.e. hot spots with disproportionate observations of hot moments) is poorly understood, but may help elucidate patterns and drivers of high greenhouse gas emissions from agricultural peatland soils. We used continuous chamber-based flux measurements across three land uses (corn, alfalfa, and pasture) to quantify the spatiotemporal patterns of soil greenhouse gas emissions from temperate agricultural peatlands in the Sacramento-San Joaquin Delta of California. We found that the location of hot spots of emissions varied over time and were not consistent across annual timescales. Hot moments of nitrous oxide (N₂O) and carbon dioxide (CO₂) fluxes were more evenly distributed across space than methane (CH₄). In the corn system, hot moments of CH₄ flux were often isolated to a single location but locations were not consistent across years. Spatiotemporal variability in soil moisture, soil oxygen, and temperature helped explain patterns in N₂O fluxes in the annual corn agroecosystem but were less informative for perennial alfalfa N₂O fluxes or CH₄ fluxes across ecosystems, potentially due to insufficient spatiotemporal resolution of the associated drivers. Overall, our results do not support the concept of persistent hot spots of soil CO₂, CH₄, and N₂O emissions in these drained agricultural peatlands. Hot moments of high flux events generally varied in space and time and thus required high sample densities. Our results highlight the importance of constraining hot moments and their controls to better quantify ecosystem greenhouse gas budgets.

排水农业泥炭地仅占农业用地的 1%，但据估计约占全球农田温室气体排放量的三分之一。然而，最近的研究表明，随着时间的推移，农业泥炭地的温室气体通量可能会发生几个数量级的变化。温室气体排放的这些热点时刻（对年度预算影响不成比例的个别通量）与各个室位置（即热点时刻观测到的热点）之间的关系知之甚少，但可能有助于阐明高温室气体排放的模式和驱动因素农业泥炭地土壤的排放。我们对三种土地利用（玉米、苜蓿和牧场）进行了基于室的连续通量测量，以量化加利福尼亚州萨克拉门托-圣华金三角洲温带农业泥炭地土壤温室气体排放的时空模式。我们发现排放热点的位置随着时间的推移而变化，并且在年度时间尺度上并不一致。一氧化二氮 (N ₂ O) 和二氧化碳 (CO ₂ ) 通量的热矩在空间中的分布比甲烷 (CH ₄ ) 更均匀。在玉米系统中，CH ₄通量的热点时刻通常被隔离到单个位置，但多年来位置并不一致。土壤湿度、土壤氧和温度的时空变化有助于解释一年生玉米农业生态系统中 N _{2 O 通量的模式，但对于跨生态系统的多年生苜蓿 N 2} O 通量或 CH ₄通量的信息较少，这可能是由于 N 2 O 通量的时空分辨率不足。相关驱动程序。总体而言，我们的结果不支持这些排水的农业泥炭地中土壤CO ₂、CH ₄和N ₂ O 排放持续热点的概念。高通量事件的热点时刻通常在空间和时间上有所不同，因此需要高样品密度。我们的结果强调了限制热点时刻及其控制以更好地量化生态系统温室气体预算的重要性。