Altogether 75 species of clavarioid fungi were collected from the "Kivach" strict nature reserve (middle boreal subzone of the Republic of Karelia). Among them, there are 60 species indicated for the reserve for the first time, and 44 are new to Karelia. The observed number of clavarioid species in the reserve is similar to that in other localities (~100 km2) in the European part of Russia (65-75 species), whereas further eastwards, in Siberia, this number drops by a factor of four, reaching a minimum in the ultacontinental conditions of Yakutia. A similar trend was established for clavarioid complexes on a larger scale - for continentality sectors (~100.000 km2). Similar results were observed for some groups of fungi and lichens in flatland areas of the Euro-Siberian region. The Kivach nature reserve harbors some fungal species typical of maritime climate. They are extremely rare, or absent to the east, in the continental climate. Records from Kivach were missing many typical tundra or arctic-alpine species, whereas in an ultracontinental climate they accounted for 20 % of the species number. About 40 % of species in the reserve are common in the middle boreal subzone of Eurasia, and in Yakutia this parameter rises to 70 %.