Structure of post-fire ectomycorrhizal communities of Scots pine stand in a dry coniferous forest habitat

Ectomycorrhizal communities associated with Pinus sylvestris growing on dry coniferous forest habitat after the fire were studied. In order to investigate the fire effect on ectomycorrhizal fungi and changes of soil parameters in the upper (0-15 cm) soil layer three study plots were established: 1 - the control, 2 - fire zone left for artificial renewal (with the economic method of renewal) and 3 - fire zone left for natural renewal. The analysis of mycorrhizae revealed presence of eight mycorrhizal fungi on Scots pine roots and the value of Shannon-Wiener species diversity index H' equaled to 1.76. The most abundant were mycorrhizae formed by Tomentella feruginea (31.7%) and Hebeloma crustuliniforme (23.3%). The fraction of Paxillus involutus and Rhizopogon sp. mycorrhizae was 16.7% and 13.0%, respectively. The lowest was the number of Thelephora terrestris mycorrhizae (only 1.7%). At the site 2, number of mycorrhizal fungi diminished to five and Shannon-Wiener species diversity index was also lower (1.37). The predominant were mycorrhizae of Cenococcum geophilum (26.7%) and P involutus (21.7%), whilst the lowest were mycorrhizae of Suillus luteus (1.7%). Although at the third site the number of ectomycorrhizal fungi was the same as on the site 2, the dominance of Thelephora terrestris (66.7%) caused that Shannon-Wiener's species diversity index was the lowest (1.05). Mycorrhizae of Paxillus involutus and Wilcoxina mikolae were characterised by similar abundance (13.3% and 11.7%, respectively). The lowest number of mycorrhizae was observed for Tomentella sp. (3.3%). Analysis of soil parameters showed an increase of pH on burnt sites in comparison to the control. The soil of burnt sites were also characterised by lower value of C and C/N ratio than the soil on the control treatment. The result showed that ubiquitous mycorrhizal fungi, such as T terrestis, are able to persist on roots in changed soil environment with low content of nutritions.