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

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe

Tree ring-based reconstruction of the long-terminfluence of wildfires on permafrost active layer dynamics in Central Siberia

Although it has been recognized that rising temperatures and shifts in the hydrological cycle affect the depth of the seasonally thawing upper permafrost stratum, it remains unclear towhat extent thefrequency and intensity ofwildfires, and subsequent changes in vegetation cover, influence the soil active layer on different spatiotemporal scales. Here, we use ring widthmeasurements of the subterranean stem part of 15 larch trees from a Sphagnum bog site in Central Siberia to reconstruct long-term changes in the thickness of the active layer since the lastwildfire occurred in 1899. Our approach reveals a three-step feedback loop between above- and belowground ecosystem components. After all vegetation is burned, direct atmospheric heat penetration over the first ~20 years caused thawing of the upper permafrost stratum. The slow recovery of the insulating ground vegetation reverses the process and initiates a gradual decrease of the active layer thickness. Due to the continuous spreading and thickening of the peat layer during the last decades, the upper permafrost horizon has increased by 0.52 cm/year. This study demonstrates the strength of annually resolved and absolutely dated tree-ring series to reconstruct the effects of historical wildfires on the functioning and productivity of boreal forest ecosystems at multi-decadal to centennial time-scale. In so doing, we show how complex interactions of above- and belowground components translate into successive changes in the active permafrost stratum. Our results are particularly relevant for improving long-term estimates of the global carbon cycle that strongly depends on the source and sink behavior of the boreal forest zone

Climaticaly Induced Dynamic of Radial Growth of Siberian Stone Pine and Siberian Fir in the Mountain-Taiga Belt in Ergaki National Park

В работе приводятся результаты дендроклиматических исследований, проведенных на верхней границе горно-таежного растительного пояса (1500-1600 м над уровнем моря) природного парка «Ергаки». Построено шесть древесно-кольцевых хронологий по кедру и пихте, перекрывающих временной интервал от 100 до 400 лет. Сравнительный анализ радиального прироста деревьев и основных климатических параметров среды (среднемесячной температуры воздуха и количества осадков) показал разный климатический отклик деревьев в зависимости от положения в рельефе. Для хронологий по кедру с участков I и II (Каменный город и Радужное) наиболее значимым фактором, определяющим прирост, являются температуры начала вегетационного периода (R=0,27, при p<0,05). Для кедра и пихты, произрастающих на склонах хребтов (Пик спасателей), наиболее значимо влияние температур июля (R=0,22-0,25, при p<0,05, соответственно). Использование хронологии по кедру для проведения адекватной реконструкции климата прошлого для исследуемого региона невозможно из-за низких значений регрессионного коэффициента (r2 = 0,07, при p<0,005)The results of dendroclimatic study were carrying out on the timber-line of mountain-taiga vegetation belt (1500-1600 m a.s.l.) in the Ergaki Natural Park. Six tree-ring chronologies for Siberian stone pine and Siberian fir were established. They covered the time period from 100 to 400 years. The comparison analysis between tree radial growth and the main climatic parameters of environment (monthly air temperature and amount of precipitation) showed the different climatic responses of trees depending on position in relief. The most significant factor determining the tree-ring growth for Siberian stone pine chronologies from site I and site II (Kamenniy gorod and Raduzhnoe) were the temperatures of the beginning of vegetation period (R=0,27, p<0,05). The temperatures of July were significantly correlated with tree-ring width of stone pine and fir (R=0,22 - 0,25, p<0,05, respectively) from the slopes (Peak Spasateley). Stone pine tree-ring chronology can not be used for the procedure of climatic reconstruction in the studied region because of low value of the regression coefficient (r2 = 0,07, p<0,005)