Additional nitrogen in arctic-alpine soils and plants—a pilot study with 15…

Nitrogen (N) deposition has been increasing in alpine ecosystems, but its fate in soils and plants remains unclear. We assumed that the increased N load will be efficiently retained in alpine ecosystems but that the degree of N use efficiency changes with elevation. Thus, we performed a 3-year 15N tracer experiment, in which we added 1 g m–2 of either NH415NO3 or 15NH4NO3 fertilizer to a pl…