Climate change is triggering rapid shifts in plant communities and alterations in soil abiotic conditions in peatlands, with cascading effects on belowground decomposers and ecosystem C turnover. However, elucidating the dominant causal relationships between plant communities, soil biota and C fluxes in these vulnerable ecosystems requires a better understanding of the spatio-temporal variability of abiotic and biotic drivers. In this study we investigated the effects of biotic (plant functional types, PFTs) and abiotic factors (soil temperature and soil moisture) in determining dynamic patterns of soil microbial community structure and C cycling. Four representative temperate peatland habitats were selected based on their peat forming vegetation – an Atlantic wet heathland, two active blanket bogs with herbaceous plants (Molinia caerulea and Eriophorum angustifolium), and a transition mire dominated by Sphagnum mosses located along an altitudinal gradient to include the natural variations in soil temperature and water content regimes. We found that peat microbial communities were more strongly linked to local abiotic conditions than to the dominant above-ground vegetation. Aerobic conditions and warmer temperatures accelerated fungal driven decomposition and CO₂ emissions under shrubs, whereas decreases in Gram−negative bacteria promoted increased C losses under Molinia. These findings suggest that small spatial differences in abiotic conditions can create local “hotspots” of organic matter decomposition. We propose that temperate peatlands should be considered as ‘ecosystem sentinels’ for climate change, acting as early-warning indicators of climate-carbon feedbacks.

气候变化正在引发植物群落的快速变化和泥炭地土壤非生物条件的改变，对地下分解者和生态系统碳周转产生连锁影响。然而，阐明这些脆弱生态系统中植物群落、土壤生物群和碳通量之间的主要因果关系需要更好地了解非生物和生物驱动因素的时空变异性。在这项研究中，我们研究了生物（植物功能类型，PFT）和非生物因素（土壤温度和土壤水分）在确定土壤微生物群落结构和碳循环的动态模式方面的影响。根据它们的泥炭形成植被选择了四个具有代表性的温带泥炭地栖息地——大西洋湿石南地，两个有草本植物的活跃毯状沼泽（Molinia caerulea和Eriophorum angustifolium），以及一个以泥炭藓为主的过渡泥沼，沿着海拔梯度分布，包括土壤温度和含水量状况的自然变化。我们发现泥炭微生物群落与当地非生物条件的联系比与主要的地上植被的联系更紧密。有氧条件和温暖的温度加速了灌木下真菌驱动的分解和 CO ₂排放，而革兰氏阴性细菌的减少促进了莫利尼亚下碳损失的增加. 这些发现表明，非生物条件的微小空间差异可以产生有机物质分解的局部“热点”。我们建议温带泥炭地应被视为气候变化的“生态系统哨兵”，作为气候-碳反馈的预警指标。