Динаміка товарної структури високостовбурних дубових деревостанів порослевого походження експлуатаційних лісів України

Анотація

Abstract. The norms of the dynamics of the commodity structure make it possible to estimate the assortment structure of the stock of trees of different ages, which is impossible to calculate their technical ripeness age without. At the same time, the age of the main felling of the relevant economic sections in the operational forests of Ukraine is calculated according to technical ripeness. Mistakes in the calculation of the age of the main felling lead to non-optimal forests use and significant material and financial losses. Therefore, the subject of this research is relevant.

Besides that, the development of the norms of the dynamics of the commodity structure of high-productive oak-forest porcine origin and their comparison to similar norms for oak seedlings of seed origin will allow to prove the necessity of dividing the current high-trunk oak economic section in two ones based on their origin.

The research was carried out on the basis of taxation materials of 43 temporary trial areas, which were marked on the areas allocated for the main use felling in the Left-Bank Forest Steppe.

To construct theoretical distribution series by diameter a database of 43 lists was formed. And  the following parameters of their structure were obtained with the STRUK program:

Variance variables (V), minimum (R_dmin) and maximum (R_dmax) reduction numbers were modeled as a function of the average diameter of the tree stand (D), and the variance of the business and wood parts from the business trunks share. In addition, in the process of this study the percentage of business trunks (R_dil) was determined  depending on the average diameter of the tree.

The change in the percentage of business trunks base on age of plantations was determined from the tables of the growth of the porcine oak tree species of the corresponding Site index.

Further the distribution rows for the total number and the business part of the stands at the age of 40-150 years were calculated based on the above parameters and with the BUDOVA program (β-distribution).

To model the dynamics of the commodity structure of the porous oak trees, the existing tables of the growth of the given tree species, regional assortment tables developed for the conditions of the Left Bank Forest-steppe and the pre-developed models of the parameters of the structure on the diameter of the porous oak tree stands were used.

Consequently, based on the rows of distribution of trees and assortment tables we have received the volumes of dimensional and qualitative wood categories, which were converted into relative quantities, and then into their actual stocks in relation to the total wood stocks from the growth tables.

In the article there is presented the dynamics of the commodity structure of high-yielding porcine oak stands of the II Site index in the table form. The analysis showed that the quantitative ripeness happens at 45 years old, and the technical on the saw logs one - at 95years old . It is also clear from the table that after reaching the age of 120-130 years, there is no good reason  to keep the oak varieties on the roots due to their considerable and intense damage by rotting.

The technical ripeness of rough and medium-sized business wood for oak seedlings of different productivity occurs: in the stands of the 1st Site index - at 92 years old, in the second Site index - at 109 years old and in the third one- at 120 years old.

For oak forests of seed origin of III and above Site index included in the use, the approved felling age is the same as for the II Site Index oak groves (101-110 years), although their age of technical maturation (120 and 95 years old) and biological characteristics are significantly different.

Consequently, for the higher-productivity porcine oak trees, the current age of the felling, on the contrary, is overestimated, and for seed ones it is underestimated. The unification of different origins of oak plantations into one economic section is completely unreasonable.

Conclusions. The maturity age and its associated age of the main felling in oak high-skid working forests of porcine origin (II and above Site index) of the Polissya and Forest-Steppe zones, focused on the production of cutting logs, should be established at 91-100 years old (X age class) .

In the high-skid economic section, it is not necessary to combine the porcine and seed oak-forests, as the age of maturity of the exploitation of high-skinned oak-trees of seed origin should be raised, at least, to the XII age class (111-120 years old).