THE STRUCTURE AND DYNAMICS OF MAJOR PARC FORMING TREE SPECIES SHEDDING IN THE DENDROLOGICAL PARK "ОLEXANDRIA" OF NAS OF UKRAINE

Abstract

Drying of major tree forming species has become of mass scale on the territory of Dendrological Park Olexandria. It justifies the aim of the research that is to define the structure and dynamics of woody plants shedding in the arboretum for the last 10 years to identify the main pathologies of trees of different species. The dynamics of tree shedding was determined on the basis of annual Acts on the Results of the Forest Pathology Survey of Plantations in the Territory of the Park Olexandria. The authors have visually defined the infestation of tree by diseases and pests by the presence of fruiting bodies, cancerous wounds, snipe, necrosis etc. Drying of Carpinus betulus L, Pyrus communis Mill., Populus L., Robinia pseudoacacia L. was small (25-40 exemplars) and relatively flat levels for 10 years. Most trees shedding are Acer platanoides L., Pinus sylvestris L., Betula pendula Roth., Piceа abies (L.) Karst., Tilia cordata Mill. (102-389 exemplars). T. сordata shedding was with some ups and downs, in other species it grew, reached its peak and went on the decline or continued to grow (in A. platanoides and F. excelsior). Peaks of shedding of different species did not match. Shedding centers were allocated in F. excelsior and P. abies. The cause of tree death was found only in P. abies. Drying of 180 trees was caused by bark beetle-typographer. Morphological features of F. еxcelsior drying are characteristic for a dangerous disease Chalara fraxinea, caused by invasive type of Hymenoscyphus fraxineus. On the A. platanoides massively observed necrosis-cancerous disease. Most often A. platanoides trees, like B. pendula, dried due to invisible signs of injury. On T. сordata rot, tumor, cancerous wounds were found, many trees of various ages were affected by mistletoe. The main reason of medieval P. sylvestris drying was coenotic oppression, old age – dying of conduction system. The carried analysis of the dynamics and structure of woody plants shedding in the Park Alexandria has shown that for some tree species shedding is typical high. To respond to the threats emerging recently, the organization of comprehensive research status of woody plants, studies of defeat of tree by pests and diseases, the study of the role of invasive organisms in the weakening and destruction of trees are needed.