Large-scale mining for oil extraction in the boreal forests of Northern Alberta has led to a disturbance footprint of ~900 km of land; which must be reclaimed to equivalent land capabilities. Microorganisms are sensitive to anthropogenic disturbances and play an essential role in the cycling of soil nutrients and plant growth, making them potential indicators of ecosystem function. Thus, the objective of this work was to determine the impact of land reclamation on the composition and function of soil microbial communities in the Athabasca Oil Sands Region (AOSR). We evaluated bacterial community composition via high throughput sequencing of 16S rRNA genes and soil functional diversity by community-level physiological profiling (CLPP). The ranges of variability for these factors observed in soils reclaimed with either peat-mineral mix (PMM), forest floor-mineral mix (FFM), or FFM diluted with sand (Sand-FFM), were compared to that of undisturbed reference soils (NS) and a vegetation removed soil (VR). Differences between reclamation soils and natural soils were clearly discernible, with reclamation imposing a more drastic disturbance to the boreal forest than that of removal of vegetation alone. VR changed the structure of the soil microbial community and increased the overall diversity, within-community interactions, and heterogeneity; while reclamation shifted the microbial community structure to an even greater extent, placing it outside the range of natural variability. Among reclamation substrates, FFM showed the highest level of similarity to the range of natural variability and PMM showed the least. Altogether, our findings underscore the profound impact of anthropogenic activities associated with large-scale mining on soil biological activity, microbial communities, and edaphic profiles. These alterations are of such magnitude that they render the affected soils significant divergent from the reference undisturbed boreal forest soil.

中文翻译：

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复垦和植被去除对阿萨巴斯卡油砂区土壤微生物群落组成和功能属性的影响

艾伯塔省北部北方森林的大规模石油开采已导致约 900 平方公里的土地受到干扰；必须将其恢复到同等的陆地能力。微生物对人为干扰敏感，在土壤养分循环和植物生长中发挥着重要作用，使其成为生态系统功能的潜在指标。因此，这项工作的目的是确定土地复垦对阿萨巴斯卡油砂地区（AOSR）土壤微生物群落的组成和功能的影响。我们通过 16S rRNA 基因的高通量测序评估细菌群落组成，并通过群落水平生理分析 (CLPP) 评估土壤功能多样性。将用泥炭-矿物混合物 (PMM)、森林地面-矿物混合物 (FFM) 或用沙子稀释的 FFM (Sand-FFM) 开垦的土壤中观察到的这些因素的变异范围与未扰动的参考土壤进行比较。 NS）和植被去除土壤（VR）。开垦土壤和天然土壤之间的差异显而易见，开垦对北方森林的干扰比单独去除植被更严重。 VR改变了土壤微生物群落的结构，增加了整体多样性、群落内相互作用和异质性；而开垦则更大程度地改变了微生物群落结构，将其置于自然变异范围之外。在回收基质中，FFM 与自然变异范围的相似度最高，而 PMM 的相似度最低。总而言之，我们的研究结果强调了与大规模采矿相关的人类活动对土壤生物活动、微生物群落和土壤剖面的深远影响。这些变化的幅度如此之大，以至于受影响的土壤与参考未受干扰的北方森林土壤显着不同。