Väliranta M, Salonen J S, Heikkilä M, Amon L, Helmens K, Klimaschewski A, Kuhry P, Kultti S, Poska A, Shala S, Veski S, Birks H H
Department of Environmental Sciences, ECRU, University of Helsinki, P.O. Box 65, Helsinki FI-00014, Finland.
Department of Geosciences and Geography, University of Helsinki, P.O. Box 65, Helsinki FI-00014, Finland.
Nat Commun. 2015 Apr 10;6:6809. doi: 10.1038/ncomms7809.
Holocene summer temperature reconstructions from northern Europe based on sedimentary pollen records suggest an onset of peak summer warmth around 9,000 years ago. However, pollen-based temperature reconstructions are largely driven by changes in the proportions of tree taxa, and thus the early-Holocene warming signal may be delayed due to the geographical disequilibrium between climate and tree populations. Here we show that quantitative summer-temperature estimates in northern Europe based on macrofossils of aquatic plants are in many cases ca. 2 °C warmer in the early Holocene (11,700-7,500 years ago) than reconstructions based on pollen data. When the lag in potential tree establishment becomes imperceptible in the mid-Holocene (7,500 years ago), the reconstructed temperatures converge at all study sites. We demonstrate that aquatic plant macrofossil records can provide additional and informative insights into early-Holocene temperature evolution in northernmost Europe and suggest further validation of early post-glacial climate development based on multi-proxy data syntheses.
基于沉积花粉记录的北欧全新世夏季温度重建表明，夏季温暖峰值大约在9000年前开始出现。然而，基于花粉的温度重建很大程度上受树木分类群比例变化的驱动，因此全新世早期的变暖信号可能因气候与树木种群之间的地理不平衡而延迟。我们在此表明，基于水生植物宏观化石的北欧夏季温度定量估计在许多情况下，全新世早期（11700 - 7500年前）比基于花粉数据的重建温度高约2°C。当全新世中期（7500年前）潜在树木建立的滞后变得不明显时，所有研究地点重建的温度趋于一致。我们证明，水生植物宏观化石记录可以为最北欧地区全新世早期的温度演变提供额外且有价值的见解，并建议基于多指标数据综合对冰后期早期气候发展进行进一步验证。
