Plant material
Peat mesocosms from hummocks dominated by Sphagnum fuscum(Schimp.) Klinggr. and lawns dominated by Sphagnum majus (Russ.) Jens. were collected in May and August of 2016, and July 2017, from the same site located at the northern end of the Degerö-Stormyr peatland. Degerö-Stormyr is a nutrient-poor minerogenic mire in northern Sweden (64˚11’N, 19˚33’E, 270 m asl) near Vindeln municipality that is included in the ICOS (Integrated Carbon Observation System; Franz et al ., 2018) Swedish national and European research infrastructure. Mesocosms of 20 x 20 x 25 cm were collected using a sharp knife and transferred to 11 L square plastic containers for subsequent incubation in climate-controlled growth chambers. Vascular plants (Andromeda polifolia , Rubus chamaemorus , Vaccinium oxycoccus ,Drosera rotundifolia , Empetrum nigrum , Scheuchzeria palustris, Eriophorum vaginatum and Carex spp. ) andPolytrichum spp. mosses were removed before incubation.