One of the fundamental problems of modern ecology is assessment of the response of woody plants to environmental effects under changing climate conditions on Earth. Various simulation models of tree ring growth can serve as an effective tool for solving this problem. We have proposed a new simulation model for the functioning of cambium, which reproduces the process of cambial activity of coniferous species of woody plants, depending on the action of the key climatic factors. It is based on the hypothesis of the presence of a cytoplasmic inhibitor of cell differentiation, the functioning of which is limited by temperature, moisture, and illumination. The new algorithm was developed based on the existing cambial block of the Vaganov–Shashkin simulation model of tree ring growth (VS-model). The model has been tested based on indirect observations of the functioning of the cambium of coniferous woody plants in southern Siberia (Republic of Khakassia), namely, on the measured seasonal cell production from 1964 to 2012. A software implementation of the new cambial model based on the R. Shiny technology, which can be easily adapted to the on-line platform of the VS-model, is proposed. The developed widgets (process visualization tools) make it possible to track the growth dynamics of the cambial zone to an accuracy of one-hundredth of a day.

Climate changes influence seasonal tree-ring formation. The result is a specific cell structure dependent on internal processes and external environmental factors. One way to investigate and analyze these relationships is to apply diverse simulation models of tree-ring growth. Here, we have proposed a new version of the VS-Cambium-Developer model (VS-CD model), which simulates the cambial activity process in conifers. The VS-CD model does not require the manual year-to-year calibration of parameters over a long-term cell production reconstruction or forecast. Instead, it estimates cell production and simulates the dynamics of radial cell development within the growing seasons. Thus, a new software based on R programming technology, able to efficiently adapt to the VS model online platform, has been developed. The model was tested on indirect observations of the cambium functioning in Larix sibirica trees from southern Siberia, namely on the measured annual cell production from 1963 to 2011. The VS-CD model proves to simulate cell production accurately. The results highlighted the efficiency of the presented model and contributed to filling the gap in the simulations of cambial activity, which is critical to predicting the potential impacts of changing environmental conditions on tree growth.

One of the fundamental problems of modern ecology is assessment of the response of woody plants to environmental effects under changing climate. Various simulation models of tree ring growth can serve as an effective tool for solving this problem.We developed a new cambium model which reproduces a seasonal cambial activity of conifer species and can be applied to different habitats, depending on the action of the principal climatic factors. It is based on the hypothesis of the presence of a cytoplasmic inhibitor of cell differentiation. The inhibitor functioning is connected with temperature, soil moisture, and light. The new algorithm was developed based on the existing cambial block of the Vaganov–Shashkin simulation model of tree ring growth (VS-model).The model is calibrated and verified by the direct and proxy observations of xylogenesis for conifer trees in cold semi-arid environment of Southern Siberia (the Republic of Khakassia) over 1964-2012. Accuracy of seasonal cell production simulation for the average tree of studied site was ± 1 cell .A software implementation of the new cambial model based on the R Shiny technology can be easily adapted to the on-line platform of the VS-model (VS-GENN http://www.vs-genn.ru/). The developed widgets (process visualization tools) make it possible to track the growth dynamics of the cambial zone in high resolution time scale (up to one hour).The work was supported by the Russian Ministry of Science and Higher Education (# FSRZ 2020-0010) and Russian Science Foundation (RSF#18-14-00072)