The Hudson Bay Lowlands (HBL) of northern Ontario, a globally significant carbon store, are characterized by expansive peatland complexes of patterned bogs and fens, which play a vital role in regional water regulation. These peatlands are threatened by disturbance from large-scale resource extraction and projected climate change, both of which have the potential to compromise their ecohydrological function. Field measurements and numerical modeling were used to investigate the hydrological responses of peatlands and downgradient streamflow as a consequence of disturbance from mining and shifts in climate, individually and in combination. Mine dewatering reduced groundwater storage by as much as 150 mm, equivalent to a water table lowering of 75 cm, thereby decreasing annual streamflow by 66% in impacted tributaries. Although the projected increases to precipitation and evapotranspiration due to climate change were approximately balanced, resulting in minor changes to storage, there were pronounced shifts in the temporal patterns of streamflow, with a diminished snowmelt and spring freshet occurring a month earlier. When considering the cumulative impacts of climate change coupled with mining, a potential shift in peatland ecohydrology toward new equilibria is plausible, implying altered water movement across the landscape and compromised ecosystem function. This study emphasizes the critical need for further monitoring and modeling efforts to characterize the thresholds and mechanisms driving these ecohydrological changes. This research will guide future investigations on the implications of disturbance on local and regional hydrologic connectivity and facilitate the protection of peatland ecosystems in the HBL and other northern peatland-dominated landscapes.

中文翻译：

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采矿和气候变化改变了北部泥炭地为主的集水区的储水和径流动力学


安大略省北部的哈德逊湾低地 （HBL） 是一个具有全球意义的碳储量，其特点是广阔的泥炭地复合体，由图案状的沼泽和沼泽组成，在区域水资源调节中发挥着至关重要的作用。这些泥炭地受到大规模资源开采和预计气候变化的干扰的威胁，这两者都有可能损害其生态水文功能。现场测量和数值建模用于研究泥炭地和下坡径流的水文响应，这是由于采矿干扰和气候变化单独和组合的结果。矿山脱水使地下水储量减少了 150 毫米，相当于地下水位降低 75 厘米，从而使受影响支流的年径流量减少了 66%。尽管由于气候变化导致的降水和蒸散量的预估增加大致平衡，导致储存发生微小变化，但溪流的时间模式发生了明显的变化，融雪减少，春季新鲜度提前一个月发生。当考虑到气候变化与采矿的累积影响时，泥炭地生态水文学可能向新的平衡转变是合理的，这意味着水在整个景观中的运动发生了变化，并损害了生态系统功能。本研究强调了进一步监测和建模工作的迫切需要，以描述驱动这些生态水文变化的阈值和机制。这项研究将指导未来对干扰对当地和区域水文连通性影响的调查，并促进保护 HBL 和其他北部泥炭地为主的景观中的泥炭地生态系统。