Qualitative indicators of phytomass of the crown of pine trees of the Northern Steppe of Ukraine

Abstract

Purpose. Determine the branches wood and barkdensity of the Scots pine trees of crown in the NorthernSteppe with the prospect of further developmentof regulatory support for determining the phytomass of pinecrowns of the studied region.Methods. To determine the natural and basic densityof wood and bark of branches, 25 temporary sample plotswere laid. Within temporary sample plots 25 model treeswere cut down to establish density parameters. Woodand bark cuts were performed on three model branchesfrom different parts of the crown. Measurementsof sections of model branches were carried out at fourpoints of the perimeter in two mutually perpendiculardirections. Qualitative indicators of density of woodand bark of branches were determined using the methodof Pr. Lakyda P. I., with the involvement of the applicationsoftware package ZRIZ and PLOT. Results. Studies have shown that the calculated averagevalues of natural and basic density of wood branches arehigher than the density of bark. Comparison of the averagedensity of branches with data for other natural areasof Ukraine as Polissya and Forest-Steppe revealed a moresignificant difference between the indicators of naturaldensity compared to the basic. The main statisticsof biometric indicators of trees and data of basic densityof components of pine branches are given. The resultsalso present a correlation analysis of the closenessof the relationships of qualitative components of the crownphytomass with the main biometric indicators of trees,ie age, diameter and height of tree. It is determined thatthe density of the components of the crown has a weakinverse correlation with all the biometric indexes of trees.It is established that in contrast to the natural, the basicdensity of the bark depends primarily on the age of the tree.Findings. According to the results of research on the qualityof the crown components of Scots pine trees, the averagenatural density of wood of branches is 850 kgˑ(m3)-1, barkof branches 727 kgˑ(m3)-1; the average basic density of woodand bark is 436 kgˑ(m3)-1 and 338 kgˑ(m3)-1 respectively.With increasing age, diameter and height of trees, there isa decrease in the values of both natural and basic densityof the crown components of the phytomass. The part of barkof pine branches decreases with age.