ABSTRACTRussia's West Siberian Lowland (WSL) contains the most extensive peatlands on Earth with many underlain by permafrost. We present a new database of 12 705 measurements of vertical water content and bulk soil properties from 98 permafrost and non‐permafrost cores collected in raised bogs and peat plateaus across the region, together with in‐situ measurements of surface moisture and thaw depth, botanical descriptions of dominant surface vegetation species assemblage, and field notes. Data analyses reveal significant contrasts (p < 0.01 to p < 0.0001) between permafrost and non‐permafrost sites. On average, permafrost WSL peatlands exhibit drier surfaces, shallower depth, lower organic matter content and higher bulk density than do non‐permafrost sites. Peat bulk density and ash‐free density increase with depth for non‐permafrost but not for permafrost sites. Gravimetric water content averages 92.0% near the surface and 89.3% at depth in non‐permafrost, but 81.6% and 85.4%, respectively, in permafrost, suggesting that the disappearance of permafrost could produce moister surfaces across the WSL. GIS extrapolation of these results suggests that WSL peatlands may contain ~1200 km3 of water and ice, a large storage equivalent to ~2‐m average liquid water depth and approximately three times the total annual flow in the Ob' River. A global estimate of ~6900‐km3 subsurface water storage for all northern peatlands suggests a volume comparable to or greater than the total water storage in northern lakes. The database is freely available as supplementary material for scientific use at http://onlinelibrary.wiley.com/doi/10.1002/ppp.735/suppinfo. Copyright © 2012 John Wiley & Sons, Ltd.
