Effects of lime and ash treatments on ectomycorrhizal infection of Pinus sylvestris L. seedlings planted in a pine forest

Abstract

Plots in a 40-yr-old Scots pine (Pinus sylvestris) stand in S. Sweden were treated with 5 tons tonnes? lime/ha, 7.5 tons wood-ash/ha, or left untreated. One-yr-old P. sylvestris seedlings were planted in each of the plots in early June, 12 months after ash treatment and 18 months after lime treatment. The pH of the limed, ash treated and untreated plots were 5.2, 6.4 and 3.8, respectively. Four months later 6 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 was significantly more abundant in limed soil than in ash treated soil. The results were compared with those from a previously published bioassay performed in the laboratory, where P. sylvestris seedlings had been grown in soil from the same forest. Similar soil Ph values in the 2 studies resulted in different relative infection rates of the mycorrhizal types found. All but one mycorrhizal type, designated 'white', were found in the laboratory experiment. This difference 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 in comparison with situations in which the fungi infect from propagules in the soil. (Less)