Ibutton temperature loggers ds 1922l

The Norwegian Meteorological Institute (NMI) provided mean daily interpolated data on air temperature and precipitation at a resolution of 100 m for each site for the whole study period 2014 -2016 (Norwegian Meteorological Institute, 2016) . At each site, we measured soil temperature at 5 cm below ground with MT2-05 temperature sensors (Delta-T Devices, Cambridge, UK). Due to temperature sensor malfunction of climate stations at some sites, we do not have continuous soil temperature measurements at site level for each of the incubation periods. In 2014, iButton temperature loggers (DS1922L, Maxim Integrated, San Jose, CA, USA) were buried at five locations in each site at a depth of 8 cm. Temperature data from the different sources were compared to each other both visually and by pairwise Pearson correlation for the incubation periods of the tea bags (± 3 months in summer, see method section on litter decomposition measurements) at the different sites (Figure S1). Because the temperature data of NMI for incubation periods corresponded well with both buried iButton and climate stations at all the sites, R 2 > 0.93 and R 2 > 0.83 respectively, we decided to use air temperature data from NMI in the analyses. Mean temperature and total precipitation were calculated based on data from NMI for the incubation periods of tea bags for each site and year (Table S2).