Stem production of Scots pine and black locust stands in Ukraine's Northern Steppe

The research paper presents the results of the assessment of the annual stem production of Scots pine (Pinus sylvestris L.) and black locust (Robinia pseudoacacia L.) stands within the Northern Steppe of Ukraine. The research team has developed two- and three-factor regression models for assessing the live biomass stocks for the fractions of the wood and bark of the stems of the Scots pine and black locust stands. The paper also presents the dependences of the live biomass of the components of the stems of the stands on their selected biometric parameters. The direct positive correlation between the fractions of the wood, bark, and stem in total with the factors of age, mean diameter, mean height and stand density for both the studied species has been identified. The results include the distribution of the total stem production of the Scots pine and black locust stands by the state forestry enterprises of the Dnipro region. The mean annual stem production of Scots pine is characterised by lower values (stem wood - 2.91 t.ha(-1).yr(-1), stem bark - 0.38 t.ha(-1).yr(-1) compared with the investigated species - black locust with the stem wood 4.94 t.ha(-1).yr(-1) and stem bark 1.70 t.ha(-1).yr(-1).