Semi-empirical estimation of log taper using stem profile equations

In January 2019 the forest industry in Ukraine adopted European standards for measuring and grading of round wood based on mid-point diameters, which caused major discrepancies from traditionally used estimates timber volume using top diameters. To compare methods merchantable estimation, we investigated stem form inside bark two dominant tree species Ukraine, i.e. Scots pine (Pinus sylvestris L.) common oak (Quercus robur L.). We measurements to fit profile equations, whereas simulation was applied derive log taper. found that Newnham's (1992) variable-exponent taper equation performed well predicting both species. Then, simulated structure harvested wood, so it replicated annual distribution logs by their length As a result, average estimated at 0.836 ÷ 0.855 cm·m–1 1.180 0.121 oak, respectively. The study also indicated varied along stems. higher rates diameter decrease were butt logs, 2.5–3.5 times than its whole stem. results our ensure stacked conversion between obtained