Does the calendar shift in used climate data affect the results of modeling biomass of coniferous species

Abstract

Over the past decades, there has been a continuous global warming of the climate. In Russia, for every 10 years, the total increase in atmospheric temperature is 0.61 °C and the average monthly precipitation increase is 2.2 mm. In the available publications devoted to the modeling of forest phytomass under the influence of the simultaneous action of temperatures and precipitation, the contribution of these variables to the explanation of the variability of phytomass turns out to be either insignificant or zero, mainly due to the regional level of models. The purpose of this transcontinental study is to find out whether the patterns of forest aboveground and underground phytomass change when the calendar range of averaging temperatures and precipitation for the period 1970–2000 (WorldClim version 2.1) is replaced by the averaging period for 1997–2006 (World Weather Maps, 2007) in territorial climatic gradients using the example of five coniferous of Eurasia. As a result, it was found that the contribution of the binary variable encoding two different calendar periods of averaging climatic data to the explanation of the variation in the phytomass averaged about 1%, and its significance level according to the Student was 0.74, which is lower than the standard value t₀₅ = 1.96. Thus, the hypothesis about the influence of the calendar period of averaging temperatures and precipitation on the value of the simulated aboveground and underground phytomass of conifers has not been confirmed.