The influence of nitrogen-fertilization on ectomycorrhizal mycelial colonization and infection

Total ectomycorrhizal infection level and the composition of individual infection types were investigated in young Pinus sylvestris seedlings planted in a mature Scots pine forest in southern Sweden, which was N-fertilized 13 years ago. Total ectomycorrhizal infection frequency, approximately 85%, did not differ between the fertilized and non-fertilized plots, but the infection types differed between the treatments. The different fertilizers, NH4NO3 and urea, influenced the composition of ectomycorrhizal types in different ways. There were also differences in ectomycorrhiza type composition between seedlings grown in the field and seedlings grown in soil brought into the lab