2.1 | Experimental site
The study was carried out in a mature ~100 year-old Scots pine forest (Pinus sylvestris L.) at Rosinedal, near Vindeln in northern Sweden (64°10’ N, 19°45’ E) in 2012 and 2013. The site was an even-aged and mono-specific stand, located on sandy soil. Two 15-ha plots were studied; a fertilised plot (F) and a reference plot (R). In both plots, the sparse understory was dominated by Ericaceous shrubs, esp. Vaccinium myrtillus (L.) and Vaccinium vitis-idaea , (L.) mosses (Pleurozium schreberi (Bird.) Mitt.),Hylocomium splendens (Hedw.) Shimp, and lichens (Cladonia spp.) (Hasselquist, Metcalfe, & Hödgberg, 2012; Hasselquist, Metcalfe, Marshall, Lucas, & Högberg, 2016). From 2006 through 2011 fertiliser was applied annually in mid-June to the fertilised plot (F) at a rate of 10 g N m-2 yr-1, but reduced to 5 g N m-2 yr-1 in 2012 and thereafter, using Skog-Can fertiliser (Yara, Sweden), containing NH4(13.5%), NO3 (13.5%), Ca (5%), Mg (2.4%), and B (0.2%) (Lim et al. 2015).