Abstract Palsas and peat plateaus are climatically sensitive landforms in permafrost peatlands. Climate envelope models have previously related palsa/peat plateau distributions in Europe to modern climate, but similar bioclimatic modelling has not been attempted for North America. Recent climate change has rendered many palsas/peat plateaus in this region, and their valuable carbon stores, vulnerable. We fitted a binary logistic regression model to predict palsa/peat plateau presence for North America by relating the distribution of 352 extant landforms to gridded modern climate data. Our model accurately classified 85.3% of grid cells that contain observed palsas/peat plateaus and 77.1% of grid cells without observed palsas/peat plateaus. The model indicates that modern North American palsas/peat plateaus are supported by cold, dry climates with large seasonal temperature ranges and mild growing seasons. We used palaeoclimate simulations from a general circulation model to simulate Holocene distributions of palsas/peat plateaus at 500-year intervals. We constrained these outputs with timings of peat initiation, deglaciation, and postglacial drainage across the continent. Our palaeoclimate simulations indicate that this climate envelope remained stationary in western North America throughout the Holocene, but further east it migrated northwards during 11.5–6.0 ka BP. However, palsa extents in eastern North America were restricted from following this moving climate envelope by late deglaciation, drainage and peat initiation. We validated our Holocene simulations against available palaeoecological records and whilst they agree that permafrost peatlands aggraded earliest in western North America, our simulations contest previous suggestions that late permafrost aggradation in central Canada was climatically-driven.

中文翻译：

---

北美全新世palsa分布的驱动因素

摘要 Palsas 和泥炭高原是多年冻土泥炭地气候敏感地貌。气候包络模型先前已将欧洲的palsa/泥炭高原分布与现代气候联系起来，但尚未在北美尝试类似的生物气候模型。最近的气候变化使该地区的许多palsas/泥炭高原及其宝贵的碳储存变得脆弱。我们拟合了一个二元逻辑回归模型，通过将 352 个现存地貌的分布与网格化的现代气候数据相关联来预测北美的帕萨/泥炭高原的存在。我们的模型准确分类了 85.3% 的包含观测到的palsas/泥炭高原的网格单元和 77.1% 没有观测到的 palsas/泥炭高原的网格单元。该模型表明现代北美 palsas/泥炭高原受到寒冷的支持，气候干燥，季节性温度范围大，生长季节温和。我们使用来自一般环流模型的古气候模拟来模拟以 500 年为间隔的 palsas/泥炭高原的全新世分布。我们通过整个大陆的泥炭形成、冰川消退和冰后排水的时间来限制这些输出。我们的古气候模拟表明，这种气候包络在整个全新世期间在北美西部保持静止，但在 11.5-6.0 ka BP 期间向东向北迁移。然而，由于晚期冰川消融、排水和泥炭形成，北美东部的palsa范围无法跟随这种移动的气候包络线。