LICHENICOLOUS MYCOBIOTA OF THE RUSSIAN ARCTIC. III. PARASITE-HOST ANALYSIS
Lichenicolous fungi (LF) have been found on 21 % of species and 43 % of genera of lichens from the Russian Arctic. The ratio of the number of taxa of LF to hosts is approximately 1 : 1. 78 % of LF species are confined to one specific host genus. Foliose lichens are distinguished by a high concentration of LF. Positive correlation between specialization of LF species and degree of immersion of their fruit bodies into host tissues was not observed. On rare lichen species there occurred an average of two species of LF; on sporadic taxa — three species; and on frequently found lichens — five species. Lichenicolous fungi occurred more frequently on lichens loosely attached to the substrate, than on firmly attached ones. Only 8 % of the LF species are strong pathogens, and 7 % of species induce galls. 48 % of LF species have been recorded on arctic-boreal lichens. The concentration of LF on the genuine arctic element of the host lichen biota is comparatively low. All lichen genera of the Russian Arctic with the highest numbers of associated LF also belong to the most «hospitable» world lichen genera; in both groups, Peltigera, Lecanora and Cladonia are amongst the four top genera. The most specious Russian Arctic lichen genera partly coincide with the highest richness of associated LF species.