Scots pine bait seedling performance and root colonizing ectomycorrhizal fungal community dynamics before and during the 4 years after forest clear-cut logging

The aim of the study was an integrated monitoring of Scots pine (Pinus sylvestris L.) bait seedling performance and ectomycorrhizal fungal community dynamics in a Scots pine dominated stand one growing season before and over four seasons after forest clear-cut logging. The effects of planting location and time were assessed in relation to subsequent seedling performance and ectomycorrhizal diversity. Application of advanced regeneration, where seedlings were planted one growing season before the clear-cut event, resulted in increased seedling growth in the clear-cut area over the subsequent 4 years. However, counterparts planted in the interface zone in 1997, between the future uncut stand and the clear-cut area, exhibited poorer growth compared with those planted after clear-cut harvesting. The interface zone was generally richest in ectomycorrhizal diversity, and this was confirmed using complementary morphotyping and rDNA-based identification methods. Large numbers of ectomycorrhizal types were present on Scots pine seedling roots and instead of detecting dramatic changes in total number of types, species composition changes could be better related to changes in exploratory types of ectomycorrhizas with a trend towards less rhizomorphic types in the clear-cut treatment compared with the control forest. Changes in the community structure are presumably influenced by changing environmental conditions in the site.