Active layer thaw and vegetation data for a study of soil thaw and vegetation relationship in Svalbard

Svalbards permafrost is thawing as a direct consequence of climate change. In the Low Arctic, vegetation has been shown to slow down and reduce the active layer thaw, yet it is unknown whether this also applies to High Arctic regions like Svalbard where vegetation is smaller, sparser, and thus likely less able to insulate the soil. In this dataset, we used 79 frost tubes distributed over 4 study grids located in Svalbard and with known vegetation composition to monitor the progression of active layer thaw and analyse the relationship between vegetation composition, vegetation structure and snow conditions, and soil thaw early in summer. In order to account for a large variation in timing of snowmelt and onset of soil thaw, the timing of thaw depth measurements was standardised to days since complete plot snow melt, and grouped into weekly intervals (Week of thaw: WOT). I.e. WOT1 corresponds to the week in which a plot became snow-free.