Effects of Lime and Ash Treatments on Ectomycorrhizal Infection of Pinus sylvestris L. Seedlings Planted in a Pine Forest

A pine forest in the south of Sweden was treated with lime and wood ash. In early June, 12 months after the ash treatment and 18 months after the lime treatment, one year old Pinus sylvestris L. seedlings were planted. Four months later six different ectomycorrhizal types had infected the seedlings in all the treatments. A mycorrhizal type designated "pink" was more than twice as common in the lime treatments as in the control and ash treatments. Piloderma croceum Erikss. & Hjorts. was significantly more abundant in limed soil than in ash treated soil. The results were compared to those from a bioassy performed in the laboratory, where P. sylvestris seedlings had been grown in soil from the same forest. Similar soil pH values in the two studies resulted in different relative infection rates of the mycorrhizal types found. One additional mycorrhizal type, designated "white" was found in the field experiment. This suggests that mycelial connections to the mature host plants may significantly alter the ability of different fungi to colonize host plant roots in competition with each other compared to when the fungi infect from propagules in the soil.