The current state of pine plantations and climatic changes (temperature, humidity, precipitation) in the region of research were estimated.
The actual and optimal forest cover of the Ukrainian Polissya was analyzed. The results of the analysis indicate that in the researched area the actual forest cover is less than optimal. In the context of an ever-increasing anthropogenic influence, the negative impact on the environment increases, as well as the overall sanitary condition of forests needs to be substantially improved. Reduction of the forestland covered with forest
vegetation at the Ukrainian Polissya decreases their climate stabilizing functions. The lack of forest protection measures also contributes to the growth and spread of pests and diseases. The deterioration of the forest-pathological condition of plantations causes the drying of pine plantations in Polissya.
The analysis of the total amount of CO2 emissions into the air has demonstrated its growth in 2008 – 18.3 million tons, 2010-2012 – within the limits of 17.7 million tons. In 2015, carbon dioxide emissions from stationary and non- stationary sources of pollution in the Ukrainian Polissya decreased by 31.7%, and in 2016 – increased by 9.4% in comparison with the previous year.
The climatic indices of the researched region throughout 1966–2016 were analyzed, and the tendency was find out of reduction of the annual amount of precipitation by 18 mm, the increase of the average annual temperature by 2.0 ° C, as well as the decrease of the relative humidity of air by 2%. It was identified that the climatop in the researched region remained unchanged – fresh groves (D2).
It was determined that forest conditions affect ecological functions (carbon absorption and oxygen production) of pine plantations.
In line with biometric parameters, the empirical equations were developed for the determination of the above-ground phytomass of Pinus sylvestris in different types of forest site and stand conditions, their carbon-absorbing and oxygen-producing capacity per area.
Based on these empirical equations, the reference tables were compiled to evaluate the components of the above-ground phytomass in terms of the diameter and height of trees, taking into account the types of forest site and stand conditions of Pinus sylvestris growth.
Comparison of the actual data with the normative tables indicated that on the area of 1 hectare in the А1 forest site and stand conditions, the number of trees is lower than the normative indicators by 35.8%, while in the conditions of А2 – by 42.1%, В2 – by 12.0%, В3 – by 31.6%, which has a negative impact on the Pinus sylvestris’ phytomass accumulation. Taking into account the actual areas of the forest areas covered by pine
forest vegetation of the natural origin at the Ukrainian Polissya by forest types, the total biomass of pine forests was determined. The total volume of phytomass of Pinus sylvestris in forest site and stand conditions of В3 is 55.9%, in В2 conditions – 34.8%, А2 – 8.2%, А1 – 1.1%.
It was found out that the highest density of phytomass per m2 of forestland covered with forest vegetation in the Ukrainian Polissya was represented by pine plantations in forest site and stand conditions of В2 - 29.8% and В3 – 27.4%.
The proposed reference tables for the evaluation of the above-ground phytomass of Pinus sylvestris allowed to determine the amount and stock of carbon that is absorbed in the aboveground components of a tree during the photosynthesis process. According to the results of the analysis, it was found that in А2 and В2 conditions, pine has the largest phytomass and, accordingly, has a higher carbon-absorption capability compared to other types of forest site and stand conditions.
According to the estimation of actual carbon accumulation capacity, deposit of carbon by pine plantations of Ukrainian Polissya for the period of 2007–2016 was analyzed.
The reference tables for the determination of the diffraction oxygen-producing capacity in different types of forest site and stand conditions are proposed.
For the Ukrainian Polissya, a percentage of distribution of oxygen-producing capacity was established according to the distribution of forest areas covered with forest vegetation.
It was found out that the Pinus sylvestris accumulates most phytomass in В2 forest site and stand conditions. The Pinus sylvestris demonstrated the largest carbon-absorption capacity in the А2 and В2 forest site and stand conditions. Lesser ability to accumulate carbon in phytomass the Pinus sylvestris showed in А1 and В3 forest site and stand conditions. The major oxygen-producing capacity of the Pinus sylvestris was recorded in В2 forest site and stand conditions – 10.3 million tons per year.
It was found that for the Ukrainian Polissya zone, the best conditions for growth and implementation of ecological functions by Pinus sylvestris are В2 conditions.
