Authors:
V. A. USOLTSEV, doctor of agricultural sciences, professor,
K. V. KOLCHIN, postgraduate student,
V. A. AZARENOK, doctor of agricultural sciences, professor,
Ural State Forest Engineering University (37 Sibirskiy tract Str., 620100, Ekaterinburg)
Abstract. Forests play an important role in reducing the amount of greenhouse gases in the atmosphere and preventing climate change. One way to quantify сarbon exchange in forest cover is estimating changes in its biomass and carbon pools over time. Biomass estimating on the unit of area starts with harvesting sample trees and weighing their biomass. It is known the strong and sustainable relationship between tree biomass and its diameter (simple allometry), or between tree biomass and a number of mass-forming (morphometric) indices (multi-factor allometry). At present, in different countries and continents, the studies of the applicability of the so-called generic (generalized, common) allometric models are intensified that would give acceptable accuracy in estimating forest biomass. In the article on the basis of the compiled database of tree biomass of Picea at a number of 1065 trees, allometric models of the four modifications are designed, which include the block of independent dummy variables. These models provide an opportunity to give regional estimates of tree biomass when using some known mass-forming indices (stem and crown diameter and tree height). Allometric models proposed are indicative of their adequacy for the actual data (coefficients of determination are 0.814 to 0.984) and can be applied in regional estimating of spruce tree biomass. However, generic allometric models built using the total quantity of actual data give in different ecoregions too large standard errors (up to 221 %) and unacceptable both positive and negative biases (from +311 to ‒99 %), that excludes any possibility of their application at regional levels.
Keywords: Picea L., allometric models, tree biomass, sample plots, regional differences, standard errors, biases.
