Modeled Tracheidograms Disclose Drought Influence on Pinus sylvestris Tree-Rings Structure From Siberian Forest-Steppe

Wood formation allows trees to adjust in a changing climate. Understanding what determine its adjustment is crucial to evaluate impacts of climatic changes on trees and forests growth. Despite efforts to characterize wood formation, little is known on its impact on the xylem cellular structure. In this study we apply the Vaganov-Shashkin model to generate synthetic tracheidograms and verify its use to investigate the formation of intra-annual density fluctuations (IADF), one of the most frequent climate tree-ring markers in drought-exposed sites. Results indicate that the model can produce realistic tracheidograms, except for narrow rings (<1 mm), when cambial activity stops due to an excess of drought or a lack of growth vigor. These observations suggest that IADFs are caused by a release of drought limitation to cells formation in the first half of the growing season, but that narrow rings are indicators of an even more extreme and persistent water stress. Taking the example of IADFs formation, this study demonstrated that the Vaganov-Shashkin model is a useful tool to study the climatic impact on tree-ring structures. The ability to produce synthetic tracheidogram represents an unavoidable step to link climate to tree growth and xylem functioning under future scenarios

Contribution of xylem anatomy to tree-ring width of two larch species in permafrost and non-permafrost zones of Siberia

Plants exhibit morphological and anatomical adaptations to cope the environmental constraints of their habitat. How can mechanisms for adapting to contrasting environmental conditions change the patterns of tree rings formation? In this study, we explored differences in climatic conditions of permafrost and non-permafrost zones and assessed their influence on radial growth and wood traits of Larix gmelinii Rupr (Rupr) and Larix sibirica L., respectively. We quantified the contribution of xylem cell anatomy to the tree-ring width variability. Comparison of the anatomical tree-ring parameters over the period 1963–2011 was tested based on non-parametric Mann-Whitney U test. The generalized linear modeling shows the common dependence between TRW and the cell structure characteristics in contrasting environments, which can be defined as non-specific to external conditions. Thus, the relationship between the tree-ring width and the cell production in early- and latewood are assessed as linear, whereas the dependence between the radial cell size in early- and latewood and the tree-ring width becomes significantly non-linear for both habitats. Moreover, contribution of earlywood (EW) and latewood (LW) cells to the variation of TRW (in average 56.8% and 24.4% respectively) was significantly higher than the effect of cell diameters (3.3% (EW) and 17.4% (LW)) for the environments. The results show that different larch species from sites with diverging climatic conditions converge towards similar xylem cell structures and relationships between xylem production and cell traits. The work makes a link between climate and tree-ring structure, and promotes a better understanding the anatomical adaptation of larch species to local environment conditions

Comparing Forest Measurements from Tree Rings and a Space-Based Index of Vegetation Activity in Siberia

Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetationindex (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much ofSiberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record

Editorial: Revisiting the limits of plant life - plant adaptations to extreme terrestrial environments relating to astrobiology and space biology

Plants were essential to the early evolution of terrestrial life and colonization of the young Earth (Kapoor et al., 2023). Plant communities continue to colonize and transform our planet including the newest ecosystems formed post-glaciation, restoring those degraded by human activities and adapting to changing ecological conditions (Huston and Smith, 1987; Chapin et al., 1994; Yuan et al., 2020; Heim et al., 2021). Plants cannot move away from a harmful stimulus, and thus, have evolved remarkable strategies to survive and eventually thrive in harsh environments. Today, humanity is on the verge of exploring our solar system and beyond, eager to discover, answer fundamental questions, and search for extraterrestrial forms of life. Undoubtedly, plants are key organisms to successful deep space missions and independence from the provision of terrestrial resources, whether for long duration interplanetary travel or establishing permanent settlements. With this thought in mind, we have collated articles focusing on terrestrial plants from extreme environments and their adaptations to harsh conditions. This collective knowledge will advance the selection of desired plant characteristics relevant to human space mission

Methodology for Development of a 600-Year Tree-Ring Multi-Element Record for Larch from the Taymir Peninsula, Russia

We developed a long (600-year) dataset for the concentrations of 26 elements in tree rings of larch from the Taymir Peninsula, the northernmost region in the world (ca. 72°N) where trees grow. Tree rings corresponding to the time period from 1300 to 1900 A.D. were studied. Eleven wood strips, each from a different larch tree, were cut into ca. 100 mg samples usually consisting of ten consecutive tree rings (but occasionally five). Between 19 and 40 consecutive samples resulted from each tree, yielding a total of 277 samples. The replication of each time interval ranged from three (for periods 1300-1400 A.D. and 1600-1700 A.D.) to six (for 1450-1600 A.D.). Wood samples were digested with concentrated HNO 3 for measurement of Li, B, Na, Mg, Al, Si, P, Cl, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, Sn, Sb, I, Ba, La, Ce, Nd, W, Au, Pb, Bi, Th, and U using solution Inductively Coupled Plasma Mass Spectrometry (ICPMS). Fourteen elements (V, Co, As, Y, Nb, Mo, Sb, La, Ce, Nd, W, Au, Th, and U) with extremely low concentrations were eliminated from consideration as unreliable. Here we report our sample preparation and measurement procedure, as well as the observed concentrations in tree rings, emphasizing considerations for developing representative and reliable denrodochemical datasets.Нами был получен длительный массив данных (600 лет) концентраций 26 элементов в годичных кольцах лиственницы с полуострова Таймыр, самого северного региона в мире (около 72° с.ш.), где возможен рост деревьев. Изучались годичные кольца, соответствующие промежутку времени с 1300 по 1900 год н.э. Одиннадцать древесных выпилов, по одному для каждой лиственницы, нарезались на образцы массой около 100 мг, которые, как правило, состояли из десяти годичных колец (но в некоторых случаях из пяти). Из каждого дерева было получено от 19 до 40 последовательных образцов, что дало в общей сложности 277 образцов. Повторность для каждого временного интервала варьировала от трех (для периодов 1300-1400 г.н.э. и 1600-1700 г.н.э.) до шести (для периода 1450-1600 г.н.э.). Древесные образцы растворяли в концентрированной HNO 3 для последующего измерения Li, B, Na, Mg, Al, Si, P, Cl, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, Sn, Sb, I, Ba, La, Ce, Nd, W, Au, Pb, Bi, Th и U при помощи масс-спектрометрии с индуктивно связанной плазмой (ICP-MS) для растворов. Четырнадцать элементов (V, Co, As, Y, Nb, Mo, Sb, La, Ce, Nd, W, Au, Th и U) с очень низкими концентрациями были исключены из рассмотрения как недостоверные. В данной статье, основной целью которой являлась отработка методики получения репрезентативных и достоверных дендрохимических данных, приводится использованная нами процедура пробоподготовки и измерений, а также полученные концентрации в годичных кольцах

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

Growth-limiting factors and climate response variability in Norway spruce (Picea abies L.) along an elevation and precipitation gradients in Slovenia

Norway spruce (Picea abies L.) is among the most sensitive coniferous species to ongoing climate change. However, previous studies on its growth response to increasing temperatures have yielded contrasting results (from stimulation to suppression), suggesting highly site-specific responses. Here, we present the first study that applies two independent approaches, i.e. the nonlinear, process-based Vaganov-Shashkin (VS) model and linear daily response functions. Data were collected at twelve sites in Slovenia differing in climate regimes and ranging elevation between 170 and 1300 m a.s.l. VS model results revealed that drier Norway spruce sites at lower elevations are mostly moisture limited, while moist high-elevation sites are generally more temperature limited. Daily response functions match well the pattern of growth-limiting factors from the VS model and further explain the effect of climate on radial growth: prevailing growth-limiting factors correspond to the climate variable with higher correlations. Radial growth correlates negatively with rising summer temperature and positively with higher spring precipitation. The opposite response was observed for the wettest site at the highest elevation, which positively reacts to increased summer temperature and will most likely benefit from a warming climate. For all other sites, the future radial growth of Norway spruce largely depends on the balance between spring precipitation and summer temperature

Modeled Tracheidograms Disclose Drought Influence on Pinus sylvestris Tree-Rings Structure From Siberian Forest-Steppe

Wood formation allows trees to adjust in a changing climate. Understanding what determine its adjustment is crucial to evaluate impacts of climatic changes on trees and forests growth. Despite efforts to characterize wood formation, little is known on its impact on the xylem cellular structure. In this study we apply the Vaganov-Shashkin model to generate synthetic tracheidograms and verify its use to investigate the formation of intra-annual density fluctuations (IADF), one of the most frequent climate tree-ring markers in drought-exposed sites. Results indicate that the model can produce realistic tracheidograms, except for narrow rings (< 1 mm), when cambial activity stops due to an excess of drought or a lack of growth vigor. These observations suggest that IADFs are caused by a release of drought limitation to cells formation in the first half of the growing season, but that narrow rings are indicators of an even more extreme and persistent water stress. Taking the example of IADFs formation, this study demonstrated that the Vaganov-Shashkin model is a useful tool to study the climatic impact on tree-ring structures. The ability to produce synthetic tracheidogram represents an unavoidable step to link climate to tree growth and xylem functioning under future scenarios