Abstract The understory is an important reservoir of plant biodiversity and a driver of ecological processes in Canada's boreal forest, making its re-establishment following reclamation of oil sands mines crucial. This study examined understory plant community development with time using two cover soil types (forest floor mineral mix (FMM) and peat mineral mix (PMM)) in Alberta oil sands reclamation sites. Cover soil type played a significant role in plant community development with FMM soil having greater species richness, diversity and total vegetation cover than PMM four years after reclamation. Nonmetric multi dimensional scaling and multi response permutation procedure revealed no compositional differences between the cover soil types. Indicator species analysis showed FMM cover soil was dominated by perennial species while PMM was dominated by annual forb species. This implies that FMM cover soil leads to faster vegetation recovery (from ruderal and annual communities to perennial communities) than PMM cover soil. Non-native species declined with time in FMM (7.5–4%) and increased in PMM (8.9–12.5%). We therefore recommend utilizing FMM as cover soil to promote productive and diverse understory plant communities on the reclaimed landscape.

中文翻译：

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再生油砂早期北方森林林下植物群落发展

摘要 林下是植物生物多样性的重要库，也是加拿大北方森林生态过程的驱动力，因此在油砂矿开垦后重建林木至关重要。本研究使用艾伯塔油砂开垦场的两种覆盖土壤类型（森林地面矿物混合物 (FMM) 和泥炭矿物混合物 (PMM)）检查了林下植物群落随时间的发展。覆盖土类型在植物群落发展中发挥了重要作用，开垦四年后 FMM 土壤的物种丰富度、多样性和总植被覆盖率高于 PMM。非度量多维缩放和多响应排列程序显示覆盖土壤类型之间没有组成差异。指示种分析表明，FMM覆盖土壤以多年生物种为主，而PMM以一年生杂草物种为主。这意味着 FMM 覆盖土壤比 PMM 覆盖土壤导致更快的植被恢复（从原始和一年生群落到多年生群落）。非本地物种在 FMM 中随时间下降（7.5-4%），在 PMM 中随时间增加（8.9-12.5%）。因此，我们建议使用 FMM 作为覆盖土壤，以促进开垦景观上多产和多样化的林下植物群落。