Tree canopy impacts on moss growth, microbiome and nitrogen fixation rates in the boreal forest

Nitrogen (N) is a limiting nutrient for plant growth in boreal and temperate forests. N-fixation by moss-dwelling bacteria is an important process in boreal ecosystems. Field-based experiments (Alaska), a chronosequence (Quebec), and coastal forests (New Brunswick) were used to investigate how canopy composition and age control moss community assembly, growth, N-fixation, and microbiome. Interactions among canopy composition and local climate can alter moss contributions to biodiversity, and carbon and N cycling. Consequently, climate-induced shifts in canopy dominance, as have been recorded in northwestern North America, are likely to have profound impacts on moss communities, their microbiome, and ecosystem functions.