Comprehensive Hydrological Survey of Glukhoye Lake, a Typical Forest Lake on Kunashir Island (Kuril Islands)

In order to study a typical forest lake on Kunashir Island, which is Glukhoye Lake, a bathymetric mapping was conducted using a Lowrance echo sounder, during which 25 transects and 3 longitudinal tacks were measured. According to the results of bathymetric mapping, 5 points of hydrological and hydrochemical synchronous survey were carried out, within the framework of which hydrochemical indicators were measured and 9 water samples were taken for further analysis. At the same locations, 5 sediment samples were collected and described during the ground survey. Based on these studies, a comprehensive hydrological characterization of Glukhoye Lake, a typical forest lake on Kunshir Island, has been formulated. It is located in a forested area between the hills, has a shallow basin, few tributaries and slow water exchange. The lake is characterized by very little variability in hydrochemical parameters in depth and in plan. The predominance of hydrocarbonate and sodium ions is quite typical for surface water bodies of volcanic massifs. The hypothesis of a continuing close link between the lake and the ocean has not been confirmed

A Modified Algorithm for Estimating the Radial Cell Size in the Vaganov-Shashkin Simulation Model

Понимание механизма формирования и роста годичных колец древесных растений под влиянием ведущих факторов внешней среды является одной из самых актуальных проблем современной дендроэкологии. Ускорение или замедление скорости роста дерева в отдельные интервалы сезона определяется совместным влиянием таких климатических факторов, как температура и влажность почвы. С использованием модифицированного алгоритма имитационной модели роста древесных растений Ваганова-Шашкина – VS-осциллографа – в работе моделируется сезонный рост клеток в годичном кольце. Предложен новый математический подход к оценке камбиальной активности хвойных и сезонной клеточной продукции, который был протестирован на образце сосны обыкновенной (Pinus sylvestris L.), отобранном в Хакасии, за период с 1969 по 2008 гг. Благодаря данному подходу удалось разделить влияние климатических и неклиматических внешних факторов на формирование клеток в годичном кольце древесных растенийTo describe the mechanism of tree-ring formation in woody plants influencing by the leading environmental factors is one of the most urgent problems of modern dendroecology. Changing of the tree-ring growth rate at selected intervals in the growing season is determined by the complex influence of climatic factors (e.g. temperature and soil moisture). Using the modified algorithm of the simulation model of growth Vaganov-Shashkin – VS-oscilloscope seasonal growth of cells in tree ring is simulated in the work. New mathematical approach is developed to estimate a cambial activity and seasonal cell production of conifer species. The approach is tested on tree-ring sample of Pinus sylvestris for Khakassian region over 1969-2008. The obtained approach allows to separate a treering growth signal on two components caused by climatic and non-climatic factor

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

В дендрохронологии используется большое количество различных аналитических подходов для анализа данных, одним из которых является моделирование. При создании любой модели одним из главных вопросов выступает выбор главных факторов. Самые распространенные и доступные климатические данные – температура и осадки. На основании имитационной модели Ваганова-Шашкина предложен новый алгоритм визуальной параметризации роста годичных колец хвойных деревьев, названный «VS- осциллограф», и описана его программная реализация. Полученный алгоритм был апробирован на двух породах древесных растений – Larix gmelini и Picea obovata. Новый способ параметризации и анализ моделируемых результатов позволяют оценить локальные условия произрастания древесных растений на основе динамики двух климатических переменных: температуры и осадков, без привлечения дополнительной информации о местообитанииThere are many different methods and tools for data analysis in dendrochronology. Modeling is one of them. One of the main issues in modeling is a choice of the main factors. Сlimatic data (temperature and precipitation) are the most common and affordable of them. Based on Vaganov – Shaskin model the new algorithm of visual parameterization of three-ring growth – VS-oscilloscope was developed. Algorithm was tested on different species of woody plants – Larix gmelini and Picea obovata. A new parameterization and analysis of modeling results help to evaluate conditions of area of growth of woody plants, based on dynamic of two climate variables: temperature and precipitation, without adding information about area of growt

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

В дендрохронологии используется большое количество различных аналитических подходов для анализа данных, одним из которых является моделирование. При создании любой модели одним из главных вопросов выступает выбор главных факторов. Самые распространенные и доступные климатические данные – температура и осадки. На основании имитационной модели Ваганова-Шашкина предложен новый алгоритм визуальной параметризации роста годичных колец хвойных деревьев, названный «VS- осциллограф», и описана его программная реализация. Полученный алгоритм был апробирован на двух породах древесных растений – Larix gmelini и Picea obovata. Новый способ параметризации и анализ моделируемых результатов позволяют оценить локальные условия произрастания древесных растений на основе динамики двух климатических переменных: температуры и осадков, без привлечения дополнительной информации о местообитанииThere are many different methods and tools for data analysis in dendrochronology. Modeling is one of them. One of the main issues in modeling is a choice of the main factors. Сlimatic data (temperature and precipitation) are the most common and affordable of them. Based on Vaganov – Shaskin model the new algorithm of visual parameterization of three-ring growth – VS-oscilloscope was developed. Algorithm was tested on different species of woody plants – Larix gmelini and Picea obovata. A new parameterization and analysis of modeling results help to evaluate conditions of area of growth of woody plants, based on dynamic of two climate variables: temperature and precipitation, without adding information about area of growt

A Modified Algorithm for Estimating the Radial Cell Size in the Vaganov-Shashkin Simulation Model

Понимание механизма формирования и роста годичных колец древесных растений под влиянием ведущих факторов внешней среды является одной из самых актуальных проблем современной дендроэкологии. Ускорение или замедление скорости роста дерева в отдельные интервалы сезона определяется совместным влиянием таких климатических факторов, как температура и влажность почвы. С использованием модифицированного алгоритма имитационной модели роста древесных растений Ваганова-Шашкина – VS-осциллографа – в работе моделируется сезонный рост клеток в годичном кольце. Предложен новый математический подход к оценке камбиальной активности хвойных и сезонной клеточной продукции, который был протестирован на образце сосны обыкновенной (Pinus sylvestris L.), отобранном в Хакасии, за период с 1969 по 2008 гг. Благодаря данному подходу удалось разделить влияние климатических и неклиматических внешних факторов на формирование клеток в годичном кольце древесных растенийTo describe the mechanism of tree-ring formation in woody plants influencing by the leading environmental factors is one of the most urgent problems of modern dendroecology. Changing of the tree-ring growth rate at selected intervals in the growing season is determined by the complex influence of climatic factors (e.g. temperature and soil moisture). Using the modified algorithm of the simulation model of growth Vaganov-Shashkin – VS-oscilloscope seasonal growth of cells in tree ring is simulated in the work. New mathematical approach is developed to estimate a cambial activity and seasonal cell production of conifer species. The approach is tested on tree-ring sample of Pinus sylvestris for Khakassian region over 1969-2008. The obtained approach allows to separate a treering growth signal on two components caused by climatic and non-climatic factor

Forward Modeling Reveals Multidecadal Trends in Cambial Kinetics and Phenology at Treeline

Significant alterations of cambial activity might be expected due to climate warming, leading to growing season extension and higher growth rates especially in cold-limited forests. However, assessment of climate-change-driven trends in intra-annual wood formation suffers from the lack of direct observations with a timespan exceeding a few years. We used the Vaganov-Shashkin process-based model to: (i) simulate daily resolved numbers of cambial and differentiating cells; and (ii) develop chronologies of the onset and termination of specific phases of cambial phenology during 1961–2017. We also determined the dominant climatic factor limiting cambial activity for each day. To asses intra-annual model validity, we used 8 years of direct xylogenesis monitoring from the treeline region of the Krkonoše Mts. (Czechia). The model exhibits high validity in case of spring phenological phases and a seasonal dynamics of tracheid production, but its precision declines for estimates of autumn phenological phases and growing season duration. The simulations reveal an increasing trend in the number of tracheids produced by cambium each year by 0.42 cells/year. Spring phenological phases (onset of cambial cell growth and tracheid enlargement) show significant shifts toward earlier occurrence in the year (for 0.28–0.34 days/year). In addition, there is a significant increase in simulated growth rates during entire growing season associated with the intra-annual redistribution of the dominant climatic controls over cambial activity. Results suggest that higher growth rates at treeline are driven by (i) temperature-stimulated intensification of spring cambial kinetics, and (ii) decoupling of summer growth rates from the limiting effect of low summer temperature due to higher frequency of climatically optimal days. Our results highlight that the cambial kinetics stimulation by increasing spring and summer temperatures and shifting spring phenology determine the recent growth trends of treeline ecosystems. Redistribution of individual climatic factors controlling cambial activity during the growing season questions the temporal stability of climatic signal of cold forest chronologies under ongoing climate change