Peatlands are habitats for a range of fragile flora and fauna species. Their eco-physicochemical characteristics make them as outstanding global carbon and water storage systems. These ecosystems occupy 3% of the worldwide emerged land surface but represent 30% of the global organic soil carbon and 10% of the global fresh water volumes. In such systems, carbon speciation depends to a large extent on specific redox conditions which are mainly governed by the depth of the water table. Hence, understanding their hydrological variability, that conditions both their ecological and biogeochemical functions, is crucial for their management, especially when anticipating their future evolution under climate change. This study illustrates how long-term monitoring of basic hydro-meteorological parameters combined with statistical modeling can be used as a tool to evaluate i) the horizontal (type of peat), ii) vertical (acrotelm/catotelm continuum) and iii) future hydrological variability. Using cross-correlations between meteorological data (precipitation, potential evapotranspiration) and water table depth (WTD), we primarily highlight the spatial heterogeneity of hydrological reactivity across the Sphagnum-dominated Frasne peatland (French Jura Mountain). Then, a multiple linear regression model allows performing hydrological projections until 2100, according to regionalized IPCC RCP4.5 and 8.5 scenarios. Although WTD remains stable during the first half of 21th century, seasonal trends beyond 2050 show lower WTD in winter and markedly greater WTD in summer. In particular, after 2050, more frequent droughts in summer and autumn should occur, increasing WTD. These projections are completed with risk evaluations for peatland droughts until 2100 that appear to be increasing especially for transition seasons, i.e. May–June and September–October. Comparing these trends with previous evaluations of phenol concentrations in water throughout the vegetative period, considered as a proxy of plant functioning intensity, highlights that these hydrological modifications during transitional seasons could be a great ecological perturbation, especially by affecting Sphagnum metabolism.

泥炭地是各种脆弱动植物物种的栖息地。它们的生态物理化学特性使其成为出色的全球碳和水存储系统。这些生态系统占全球新兴土地表面的3％，但占全球有机土壤碳的30％和全球淡水量的10％。在这样的系统中，碳的形成在很大程度上取决于特定的氧化还原条件，这些条件主要由地下水位的深度决定。因此，了解它们的水文变异性，同时影响其生态和生物地球化学功能，对于它们的管理至关重要，尤其是在预期其在气候变化下的未来演变时。这项研究说明了如何将长期的基本水文气象参数监测与统计建模相结合，可以用作评估以下各项的工具：i）水平（泥炭类型），ii）垂直（土卫三/大类连续体）和iii）未来水文变化性。利用气象数据（降水，潜在蒸散量）与地下水位深度（WTD）之间的互相关性，我们主要强调了整个地区水文反应性的空间异质性。泥炭藓占主导地位的Frasne泥炭地（法国汝拉山）。然后，根据区域IPCC RCP4.5和8.5情景，多元线性回归模型允许执行水文预测直到2100年。尽管WTD在21世纪上半叶保持稳定，但2050年以后的季节性趋势显示冬季WTD较低，夏季WTD明显较高。特别是在2050年之后，夏季和秋季应该会发生更频繁的干旱，从而增加WTD。这些预测通过对直到2100年的泥炭地干旱风险评估得以完成，尤其是在过渡季节（即5月至6月和9月至10月），泥炭地干旱似乎在增加。将这些趋势与以前在整个营养期内对水中苯酚浓度的评估进行比较，这些评估被认为是植物功能强度的代表，泥炭代谢。