Area and Carbon Content of Sphagnum Peatlands in North America and Eurasia Since the Last Glacial Maximum

The distribution and abundance of Sphagnum pollen spores in North America and Eurasia are mapped for the past 21000 years (21 ka). The spore distribution and abundance data are used to estimate the area and total carbon content in peatlands at 2000-year intervals. Area was estimated separately for North America, Europe and Asia. The present-day distribution of abundant Sphagnum spores corresponds closely to areas with peatland development, with maximum Sphagnum abundance in areas with between 630 and 1300 mm annual precipitation and between -2 degrees and 6 degrees C mean annual air temperature. During the Wisconsin glaciation, there were apparently not large areas of peatland in North America, except in Alaska. High Sphagnum spore percentages were found in eastern North America during deglaciation. Major peatland development occurred in boreal North America after 9 ka and there was a southward movement of high Sphagnum spore abundance after 5 ka in the western Great Lakes region. Major peatland development began after 9 ka in Europe and Asia. On the basis of maps of the area supporting peatlands, carbon accumulation in peatlands is estimated to be low prior to 11 ka, increased slightly between 11 and 5 ka, and greatly increased during the past 5 ka. Note: The start date for this data set is 21000 years before present (ypb) not what is shown in the temporal coverage field.本数据集绘制了过去21000年（21 ka）内，北美与欧亚大陆地区泥炭藓（Sphagnum）花粉孢子的分布与丰度特征。研究基于该孢子分布与丰度数据，以2000年为时间间隔，估算了各时期泥炭地的总面积与总碳储量，并分别针对北美、欧洲及亚洲三个区域单独开展了面积测算。 当前泥炭藓孢子丰度较高的区域，与现存泥炭地的发育分布高度吻合；泥炭藓丰度峰值出现在年降水量630~1300毫米、年平均气温-2℃~6℃的区域。威斯康星冰期阶段，北美地区除阿拉斯加外，几乎不存在大规模泥炭地。冰消期期间，北美东部区域观测到较高占比的泥炭藓孢子。距今9 ka后，北美寒带北部区域开始大规模发育泥炭地；距今5 ka后，大湖西部地区的高丰度泥炭藓孢子分布区出现南移现象。欧洲与亚洲的大规模泥炭地发育则始于距今9 ka之后。基于泥炭地分布区域的制图结果，研究估算得到泥炭地碳积累量在距今11 ka前处于较低水平，11~5 ka间略有提升，而在过去5 ka间则大幅增长。 注：本数据集的时间起点为距今21000年（years before present，ypb），而非时间覆盖范围字段中所标注的数值。