Northwestern Canada's discontinuous permafrost landscape is transitioning rapidly due to permafrost thaw, with the conversion of elevated, forested peat plateaus to low‐lying, treeless wetlands. Increasing hydrological connectivity leads to partial drainage of previously‐isolated bogs, which have been observed to subsequently develop hummock microtopography. However, the role of microtopographic features in the future trajectory of the transitioning landscape is unclear, including their potential controls on tree re‐establishment. In order to understand the role of hummocks in landscape change, research was conducted at the Scotty Creek Research Station, Northwest Territories, to measure hummock and black spruce tree physical characteristics, and assess tree and hummock spatial coverage in peat plateaus, collapse scar bogs and the advanced transitional feature known as treed bogs. Canopy coverage in all landforms and wetland hummock areal coverage was assessed using a LiDAR (Light Detection and Ranging) canopy gap fraction model and multispectral imagery. Hummocks, which are not underlain by permafrost but contain seasonal ice, support the establishment of black spruce trees due to favourable soil moisture conditions. Hummock flank moisture in treed bogs is intermediate between those of dry peat plateaus and inundated collapse scar bogs. Black spruce trees on peat plateaus and in treed bogs are significantly taller and of greater circumference than those in collapse scar bogs. The spatial distribution of hummocks and canopy coverage of black spruce trees in treed bogs collectively suggest that these features may play an important role in the advanced stages of permafrost thaw‐driven transition of the discontinuous permafrost landscape.

中文翻译：

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多年冻土融化后，山岗在重建黑云杉林中的作用

由于冻土的融化，加拿大西北部不连续的永冻土景观正在迅速转变，高架的森林泥炭高原已转变为低洼的无树湿地。水文连通性的提高导致先前隔离沼泽的部分排水，据观察，沼泽随后会形成小丘的微观形貌。但是，微地形特征在过渡景观的未来轨迹中的作用尚不清楚，包括它们对树木重建的潜在控制。为了了解山岗在景观变化中的作用，在西北地区的史考蒂溪研究站进行了研究，以测量山岗和黑云杉树木的物理特征，并评估泥炭高原树木和山岗的空间覆盖率，塌陷的疤痕沼泽和称为树木沼泽的高级过渡特征。使用LiDAR（光检测和测距）冠层间隙分数模型和多光谱图像评估了所有地貌的冠层覆盖度和湿地山岗的面积。不受永久冻土影响但含有季节性冰的高加床由于有利的土壤湿度条件而支持建立黑云杉树。树木丛生的沼泽中的山岗侧面水分介于干燥的泥炭高原和淹没的塌陷沼泽之间。泥炭高原和树木丛生的沼泽中的黑云杉树木比塌陷的疤痕沼泽中的树木高得多，周长也更大。