Bioproductivity of common oak stands in Ukrainian Polissya

Abstract

For oak stands growing in Ukrainian Polissya, an algorithm for computing their bioproductivity was worked out. It which allows reconciling the calculations with the developed models of growth and productivity of the studied forest stands. Biometric characteristics of oak stands in Ukrainian Polissya and temporary sample plots, methodology for determination of structural elements and algorithm for calculation of oak forests bioproductivity by components of aboveground live biomass and sequestered carbon are provided. Regression equations for biomass expansion factors for bark of trunks, bark of branches and foliage of oak stands, which statistically connect fractions of live biomass of stands with their mensuration parameters, are proposed. Bioproductivity of oak stands by live biomass components and site index classes is calculated. It includes total productivity of live biomass, takes into account withdrawn part of a stand, production of live biomass and carbon, and oxygen production. The industrial database "Stand-wise Mensurational Characteristics of Forests", provided by PA "Ukrderzhlisproekt", and 14 temporary sample plots (TSP), laid out in oak stands of Ukrainian Polissya, were used as an experimental material. TSP data includes accounting, cutting and evaluating components of live biomass on 82 model trees. They are an integral part of primary production research for forests of the main forest-forming tree species of Eastern Polissya of Ukraine. The age of common oak trees on TSP ranges from 10 to 103 years. The researched oak stands are characterized mainly by Ia, I, II and III site index classes, and from a wide range of relative stocking – from 0.23 to 1.28. TSPs were established on fresh (C2) and moist (C3) fairly infertile site types (9 TSP); on fresh (B2) and moist (В3) fairly fertile site types (4 TSP); moist (D3) fertile site types (1 TSP). TSPs were established in stands of artificial (9 TSP) and natural (5 TSP) origin. The basis of the research is formed by the methodology for collecting experimental data developed by P.I. Lakyda, which is based on a combination of mensurational and biometric techniques and takes into account carrying-out preparatory, field mensuration, and laboratory research stages. Reference materials for assessing bioproductivity of oak stands in Ukrainian Polissya by components of above-ground live biomass and amounts of sequestered carbon have been developed. It has been determined that oxygen productivity of common oak stands in Ukrainian Polissya depends significantly on their productivity and increases in higher site index classes, while its maximum is reached at a younger age for less productive stands.

Keywords

• common oak
• tree stand
• database
• temporary sample plot
• research scheme
• calculation algorithm
• biomass expansion factor model
• live biomass
• production
• carbon