@article {848, title = {Some effects of N on ectomycorrhizal diversity of Scots pine (Pinus sylvestris L.) in northeastern Germany. }, journal = {Water, Air and Soil Pollution}, volume = {116}, year = {1999}, pages = {135-140}, author = {W{\"o}llecke, J. and Munzenberger, B. and Huttl, R.F.} }