VS-oscilloscope: A new tool to parameterize tree radial growth based on climate conditions

Abstract

13It is generally assumed in dendroecological studies that annual tree-ring growth is adequately 14 determined by a linear function of local or regional precipitation and temperature with a set of 15 coefficients that are temporally invariant. However, various researchers have maintained that 16 tree-ring records are the result of multivariate, often nonlinear biological and physical processes. 17To describe critical processes linking climate variables with tree-ring formation, the process-18 based tree-ring Vaganov-Shashkin model (VS-model) was successfully used. However, the VS-19 model is a complex tool requiring a considerable number of model parameters that should be re-20 estimated for each forest stand. Here we present a new visual approach of process-based tree-21 ring model parameterization (the so-called VS-oscilloscope) which allows the simulation of tree-22 ring growth and can be easily used by researchers and students. The VS-oscilloscope was tested 23 on tree-ring data for two species (Larix gmelinii and Picea obovata) growing in the permafrost 24 zone of Central Siberia. The parameterization of the VS-model provided highly significant 25 positive correlations (p<0.0001) between simulated growth curves and original tree-ring 26 2 chronologies for the period 1950-2009. The model outputs have shown differences in seasonal 27 tree-ring growth between species that were well supported by the field observations. To better 28 understand seasonal tree-ring growth and to verify the VS-model findings, a multi-year natural 29 field study is needed, including seasonal observation of the thermo-hydrological regime of the 30 soil, duration and rate of tracheid development, as well as measurements of their anatomical 31 features. 32 33

New perspective on spring vegetation phenology and global climate change based on Tibetan Plateau tree-ring data

“…The daily time resolution is one of the strengths of the process model; it is therefore superior to satellite remote sensing data, which have a resolution that can range between 10 d and half a month. The process model is thus capable of accurately simulating the response of tree-ring growth to rapidly changing climatic variations (18,49). For details and validation of the models, see SI Appendix.…”

“…We used an updated tree-ring physiological VS procedure (VS-oscilloscope, vs-genn.ru/downloads/) to model the tree-ring growth process and associated climatic drivers (18). The simulation can be improved by a priori adjustments of its parameters to reflect local tree growth conditions more accurately (18,49). The daily time resolution is one of the strengths of the process model; it is therefore superior to satellite remote sensing data, which have a resolution that can range between 10 d and half a month.…”

“…Herein, we suggest a method, based on well-validated, processbased, Vaganov−Shashkin (VS)-oscilloscope model simulations of tree-ring growth data (18), to provide a unique record of vegetation phenological variability over the period 1960-2014. In this model (SI Appendix, Materials and Methods), daily weather station records are used to estimate the daily tree-ring growth rate, which is transformed into a daily rate of xylem cell production.…”

Visual Parameterization of Vaganov-Shashkin Simulation Model and its Application in Dendroecological Research

“…• ввод климатических данных суточно-го разрешения; • расчет интегральной скорости роста годичного кольца на основе входных климатических данных (Vaganov, Shashkin, 2000; (Тычков и др., 2012;Shishov et al, 2015).…”

“…Именно к этим моделям и относится имитационная модель прироста го-дичных колец древесных растений Ваганова-Шашкина (Ваганов, Шашкин, 2000;Vaganov et al, 2006;Anchukaitis et al, 2006;Evans et al, 2006;Touchan et al, 2012 (Тычков и др., 2012;Shishov et al, 2015).…”