STUDIES ON THE MYCORRHIZAL COMMUNITY INFECTING TREES IN THE LIPHOOK FOREST FUMIGATION EXPERIMENT

The mycorrhizal community in a long-term outdoor fumigation experiment was studied by counting both fruitbodies and below-ground mycorrhizas . The fruitbody populations under Scots pine showed annual successiona l changes which were not paralleled below ground. The trend below grou nd was for a continuing increase in species number with stand age. No clear effects above or below ground were attributable to fumigation tr eatments, but the fruitbodies of Paxillus involutus tended to occur in greater numbers in SO2 treated plots. By contrast, below ground the m ycorrhizas of this species were slightly adversely affected by SO2 fum igation.