This study investigates the spatio-temporal postglacial development of the vegetation in the northwestern part of the forest-tundra of northern Québec, Canada. Six lake sediment cores and 59 modern sediment samples were collected in an area of 16 by 7 km and analyzed for pollen and charcoal. Following a brief herb and shrub tundra period and a period with abundant Alnus, Picea mariana grew in the region for at least the past 4000 years, but there was a gradient across the area, with Picea growing to the west but not toward the east. The period of maximum Picea abundance varied between sites, but was generally between 1500 and 2500 years ago. Neoglacial cooling resulted in a decrease in Picea on the landscape, but the timing of the decline at any site depended on removal of Picea by fire. There was a gradient in Picea abundance across this study area, which resulted in a reconstructed spatial July temperature gradient of ∼1 °C across this 16 km region. In spite of the importance of fire in affecting local Picea populations around any lake, the paleoclimate reconstructions showed a long-term neoglacial cooling of ∼1 °C over the past 3800 cal yr BP, with superimposed century-scale fluctuations of ∼0.2 °C, corresponding to the Little Ice Age, the Medieval Warm Period, the Dark Ages Cold Period and the Roman Warm Period. High-resolution pollen records can therefore be used to reconstruct not only regional vegetation and climate history, but also local differences within small areas.

这项研究调查了加拿大魁北克北部森林苔原西北部植被的时空冰期发育。在16乘7 km的区域内收集了六个湖泊沉积物核心和59个现代沉积物样本，并分析了花粉和木炭。经过短暂的草本和灌木冻原冻土期以及富含大量nu木的时期之后，云杉云杉在该地区至少生长了4000年，但整个地区呈梯度分布，云杉云杉向西生长，但不向东生长。不同地点之间云杉的最大丰满期有所不同，但通常在1500至2500年前。新冰期冷却导致云杉减少在景观上，但是在任何地点下降的时机取决于通过火烧清除云杉。在整个研究区域中，云杉丰富度存在梯度，这导致在该16 km区域内重构的7月空间温度梯度约为1°C。尽管火灾对影响当地云杉的重要性在任何湖泊周围的人口中，古气候重建显示在过去3800 cal BP期间，长期的新冰期冷却为〜1°C，叠加的世纪级波动为〜0.2°C，对应于小冰期，中世纪的温暖时期，黑暗时代寒冷时期和罗马温暖时期。因此，高分辨率花粉记录不仅可以用于重建区域植被和气候历史，而且可以用于重建小区域内的局部差异。