Frostу craсks and basidiomycetes – causal agents of chronical decayings at the Peter the Great Botanical Garden

During two years of investigation (2016-2017), frostу craсks at Arboretum of the Peter the Great Botanical Garden (Saint-Petersburg, Russia) were identified in 383 trees of 82 taxa of 32 genera of 19 families, including 16 trees of 13 taxa of 6 genera of 3 families in gymnospermous trees and 367 trees of 69 taxa of 26 genera of 16 families in angiospermous trees. More often they may be found in Acer platanoides L. – 129 and Quercus robur L. – 76 specimen (both are species of native flora), representatives of families Aceraceae and Fagaceae dominate. The conifers are much more hardy to frostу craсks and these injuries usually heal without visible cracks, decyings or holes. Pathogenic mycobiota comprises 15 key basidiomycetes species. Frostу craсks promote trees infection by pathogenic fungi, provoking stem rots, stir up hollows of trunks, shorten their life or sometimes even cause their death. There is no clear relationship between winter hardiness of trees and frosty cracks. Constant and uninterrupted monitoring of arboreal plants is required to have timely and adequate answers for challenges of time, in conditions of climate changes.