Parasitic fungus mediates change in nitrogen-exposed boreal forest vegetation

摘要: 1 Experimental additions of N to an old-growth boreal forest resulted in elevated levels of free amino acids in leaves of the dominant dwarf-shrub Vaccinium myrtillus and increased attack from a parasitic fungus, Valdensia heterodoxa. 2 Glutamine additions to the leaf surface of V. myrtillus increased disease incidence by an average of almost three times compared to controls and suggested a causal connection between amino acid availability and fungal infection. 3 Increased abundance of the grass Deschampsia flexuosa followed N …