СРАВНТЕЛЬНАЯ ХАРАКТЕРСТКА ДУБРАВ БЕЛОРУССКОГО УКРАНСКОГО ПОЛЕСЬЯ В УСЛОВЯХ ЗМЕНЯЮЩЕГОСЯ КЛМАТА

Анотація

COMPARATIVE CHARACTERISTICS OF OAK STANDS IN BELARUSIAN AND UKRAINIAN POLISSYA IN CONDITIONS OF CLIMATE CHANGE

A. Potapenko¹, V. Usenya¹, P. Lakyda², О. Bala², L. Matushevich²

As a part of the forests of the Republic of Belarus, the oak tree is the main forest formter, forming the phytocenoses of the oak forests formation. Over the last 100 years, the share of oak forests in the forest structure has declined from 8.7% in 1901 to 3.4% in 2016. The same trend is typical for the southern part of Belarus, in the territory which grows 63% of the total area of the oak forests of the country. It is established that for the last decades the area of oak forests has decreased in the forest fund of the Gomel GPLF. At the same time, their share in the forest composition has also decreased, and in the forest fund of the Brest GPLFD - remained unchanged.

The favorable soil and climatic conditions of Polissya of Ukraine determined the formation of a diverse species composition of forests. Today, in the forests of Polissya, plantations are formed by 39 species of trees in which they act as the main breed, of which only six are the main forest-forming species of this region: pine, oak, birch, alder, poplar tremulous, spruce. Currently, there is a decline in productivity, biological stability and reproductive capacity of the oak forests of Polesye.

The purpose of the research: assessment of the current state, structure and dynamics of the oak forests of the Belarusian and Ukrainian Polesye.

According to the data of the Gomel, Brest GPLFD in the Republic of Belarus and Ukrgoslesproekt for the stands of the Volyn, Kiev, Zhytomyr, Rivne, Sumy, Chernigov regions, as well as Lviv and Khmelnytsky, which belong to the territory of Lesser Polesie of Ukraine in the forest fund of the Belarusian and Ukrainian Polessie is dominated by medium productive and highly productive oak forests with an average stand density of 0.64-0.67. The age structure of oak forests is dominated by middle-aged stands.

Also, data from the processing of the results of studies on the study of natural regeneration of forests on 48 trial plots in oak plantations were used: Oak groves 6 TP, blueberry 14 TP, sour - 19 TP and syringe 9 TP. Trial areas were laid in the oak stands of Rechitsky, Mozyr, Buda-Koshelevsky experimental forestry, Vasilevichy and Yelsky forestries of the Gomel GPLHO and GLHU "Korenevskaya experimental forest base of the Forest Institute of the National Academy of Sciences of Belarus".

For the study of  Polesie zone of Ukraine, the data of trial plots laid in oak stands of the Kiev region - 9, Zhytomyr - 25, Volyn - 27, Rovenskaya - 23 and Chernihiv - 7 temporary trial plots were used.

An analysis of the dynamics of oak forests in the forest fund of the Brest GPLFD compared to the Gomel GPLF showed that in the forest fund there is a reduction in young growth and mating plantings of oak tree stalks.

On the territory of Polissya of Ukraine, the total area of oak forests is 334.4 thousand hectares (in the territory of the Belarusian Polesie - 179.9 thousand hectares). The most common are in Zhytomyr (35.3%), Chernigov (16.4%) and Volyn (14.7%) areas. On the territory of other areas, which belongs to the Polesie, Kiev, Lviv, Rivne, Sumy and Khmelnitsky zones, the area of oak stands is less than 10%, and ranges from 1.9% to 9.4%.

The largest share in the Belarusian and Ukrainian Polesie is occupied by stands of natural origin. The second place in the area is occupied by oak plantings of artificial origin, created mainly by planting seedlings and sowing seeds. A significant percentage in Ukraine is occupied by oak stands of vegetative origin.

In the forest fund of the Belorussian and Ukrainian Polissya, mixed oak stands (3-4 units of oak) are the most common, and pure oak (8-9 oak) stands occupy small areas. Other stands, in which the oak leaves appear as the main breed, regardless of the coefficient of content in the stands composition (from 5 to 8 units), are also slightly distributed. This pattern indicates that the oak tree in the natural climatic and forest conditions of the Belorussian and Ukrainian Polesye forms predominantly mixed plantations of diverse origin, which are complex in composition.