Many tropical mountain peatlands in the Andes are formed by cushion plants. These unique cushion plant peatlands are intensively utilized for grazing and are also influenced by climate change, both of which alter hydrologic conditions. Little is known about the natural hydroperiods and greenhouse gas fluxes of these peatlands or the consequences of hydrologic alteration for these fluxes. Therefore, our objectives were to assess how carbon dioxide (CO₂) and methane (CH₄) fluxes varied across a hydrological gradient caused by ditching and evaluate how short-term carbon cycling responds after rewetting from ditch blocking in a tropical mountain peatland. The study was carried out in Huascarán National Park, Peru using static chamber methods. Comparing reference to highly drained conditions, mid-day net ecosystem exchange (NEE) was higher (1.07 ± 0.06 vs. 0.76 ± 0.11 g CO₂ m⁻² h⁻¹), and the light compensation point for CO₂ uptake was lower. Gas fluxes were relatively stable in the rewetted and reference treatments, with small positive responses of NEE to rising water tables. CH₄ emissions averaged 2.76 ± 1.06 mg CH₄ m⁻² day⁻¹, with negative fluxes at water tables >10 cm below the soil surface, and positive fluxes at higher water levels. Our results indicate that undrained peatlands appear to be carbon sinks, highly drained peatlands were likely carbon sources, and rewetting of moderately drained peatlands increased NEE and the ability to store carbon to undrained reference conditions. Ditching of peatlands will likely increase their susceptibility to negative climate change impacts, and hydrologic restoration could moderate these impacts.

中文翻译：

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地下水位和短期沟渠恢复对秘鲁科尔迪勒拉布兰卡山区泥炭地碳循环的影响

安第斯山脉的许多热带山区泥炭地都是靠垫层植物形成的。这些独特的垫层植物泥炭地被广泛用于放牧，并且还受到气候变化的影响，两者都会改变水文条件。对这些泥炭地的自然水文周期和温室气体通量，或这些通量的水文变化的后果知之甚少。因此，我们的目标是评估二氧化碳（CO ₂）和甲烷（CH ₄）通量在由沟渠引起的水文梯度上变化，并评估了热带山区泥炭地从沟渠阻塞重新润湿后短期碳循环的响应。这项研究是在秘鲁的瓦斯卡兰国家公园采用静室法进行的。与高度排水的条件相比，日中生态系统净交换量（NEE）更高（1.07±0.06和0.76±0.11 g CO ₂  m ^-2  h ^-1），并且吸收CO ₂的光补偿点较低。再湿润和参考处理中的气体通量相对稳定，NEE对地下水位上升的积极响应较小。CH ₄排放平均2.76±1.06 mg CH ₄  m ^-2 天^-1，地下水位大于土壤表面以下10 cm处为负通量，较高水位为正通量。我们的结果表明，不排水的泥炭地似乎是碳汇，高度排水的泥炭地可能是碳源，对中等排水的泥炭地进行重新湿润会增加NEE和将碳储存在不排水的参考条件下的能力。放弃泥炭地可能会增加其对负面的气候变化影响的敏感性，而水文恢复可能会缓解这些影响。