The species composition of xylotrophic basidiomycetes on woody plants listed in Red Book of the Crimea was studied. Xylotrophic basidiomycetes were detected on 10 species of protected woody plants of the Crimea: Arbutus andrachne - 3 species, Crataegus pojarkovae - 13, Juniperus deltoides - 2, Juniperus excelsa - 7, Malus sylvestris - 9, Pinus brutia - 3, Pistacia mutica - 15, Taxus baccata - 5, Tilia dasystyla - 2, Vitex agnus-castus - 1 species. A total of 46 species were identified. All discovered species of fungi belong to 8 orders, 20 families and 39 genera of Basidiomycota division. The order Polyporales dominates by the number of species of fungi - 18 species. There are 9 species in the orders Agaricales and Hymenochaetales. Xylotrophic basidiomycetes of the orders Hymenochaetales and Polyporales (27 species) are the most dangerous to protected species of woody plants. The greatest danger to growing trees are 12 species of fungi from the orders Hymenochaetales and Polyporales. Among the xylotrophic macromycete polyphagans, the most dangerous are Phellinus torulosus and Ganoderma applanatum , with a range of 100 and 82 host plants, respectively. Among the specialized xylotrophic basidiomycetes, Pyrophomes demidofii on Juniperus excelsa is the most common in park and forest plantations of the Southern Coast of the Crimea.

New record of Allium ursinum L. in Crimea considerably extends the current view on distribution of this species. The relict populations are well adapted to the Cri mean habitats. Therefore, the only threat to the species is not a change in the environmental conditions, but its active collection by the local population. Considering the rarity of A. ursinum in Crimea, its relict character and threats, we recommend to include this species in the new edition of the Red Data Book of Crimea.

The species composition of the indigenous woody plants of theCrimeawas studied. For the peninsula, 165 species of 58 genera and 31 families were recorded. 148 forms for 50 species of woody plants from 34 genera as well as 11 hybrids for 6 species of plants have been described. In total, there are 320 taxa of woody plants in theCrimea. Of them, 24 species are included in Red Data Book. Woody plants are distributed unevenly across the territory of the Crimea: Crimean Steppe (CS) - 1 species, Crimean Forest-Steppe (CFS) - 5, Mountanious Crimea (MC) - 37, Crimean Southern Coast (CSC) -7, CS+CFS+VC+ CSC - 26, CS+CFS+ CSC - 3, CS+ CSC - 2, CS+CFS+MC - 4, CS+CFS - 2, CS+MC+ CSC - 2, CS+MC -1, CFS+MC+ CSC - 30, CFS+ CSC - 5, CFS+MC - 14, MC+ CSC - 27 species. Dominating are the genera:Rosa- 16 species, Rubus - 21, Crataegus - 15. There are 101 species of shrubs and 64 species of trees; of them evergreen deciduous trees - 1, coniferous - 8, evergreen shrubs - 10, deciduous species - 146 species. Locally distributed are 19 species of the following genera: Arbutus, Betula, Daphne, Myricaria, Nitraria, Rubus, Ruscus, Vitex.

According to the results of phytosanitary monitoring in the Arboretum of the NBG, 26 pest species were identified on 97 tree introduced species (1039 foci). In the Arboretum of the NBG in 2020, 27 species of phytopathogenic fungi (186 foci) were identified on 65 species of woody plants. Of these, 18 species are wood-destroying fungi that cause root and trunk rot in 57 species of tree introduced species (159 foci). In the Arboretum, 5 types of powdery mildew fungi (9 foci) and 4 types of fungi that cause rust (18 foci) were identified. The results of phytosanitary monitoring for the period 2015-2020 were summed up. The number of pest species increased by 8 species and amounted to 26 species of phytophagans, the number of pest foci increased by 32%. The number of foci of phytopathogenic bracket fungi that cause root and trunk rot increased from 103 to 159 units, the increase in foci of pathogens was 56 units. Currently, the number of bracket fungi that cause root rot is 7 species (135 foci), bracket fungi that cause trunk rot - 11 species (24 foci). The number of powdery mildew and rust fungi did not change during the studies. The biology and ecology of cottony-cushion scale ( Icerya purchasi ) was studied.