Tree Rings Of Scots Pine Research Articles

Properties of ions may explain elemental stoichiometry in late- and early-wood: a case study in Scots pine tree rings

Properties of ions may explain elemental stoichiometry in late- and early-wood: a case study in Scots pine tree rings

Effects of High and Low Aerotechnogenic Emissions of Heavy Metals on Wild Plants

This article presents the results of research on the influence of polymetallic-dust aerial emissions on the pollution levels in the soil and plants by heavy metals, which have been under the impact of the “Severonickel” smelter complex on the Kola peninsula (Russia) for more than 40 years. Research using soil and plant indicators was carried out at monitoring plots in the years 1980–1999 (with high aerotechnogenic emissions) and 2000–2019 (with low aerotechnogenic emissions). The organic horizon (forest litter) of the Al-Fe-humus podzol, assimilation organs of Vaccinium myrtillus L., V. vitis-idaea L., V. uliginosum L., Empetrum hermaphroditum Hagerup, and Pinus sylvestris L. as well as tree rings of Scots pine were used for bioindication research. The content of heavy metals was determined using the AAS method. During these time periods, the emissions of polymetallic dust decreased 3.5 fold, while the level of forest litter contamination with heavy metals in the buffer and impact zones increased by 2–5 times, resulting in increased phytotoxicity of the soil and reduced habitat quality for forest plants. At present, the content of Ni and Cu in the leaves (needles) of the plant indicators in the impact zone has decreased by 3–8 times compared with 1980–1999 but their elevated levels pose a potential health risk. The decrease in atmospheric emissions of pollutants led to a 1.5-fold increase in the width of the annual rings of pine trunks in the impact zone, which may indicate the beginning of the recovery of pine-trunk-wood productivity.

Analysis of climate changes in the forest fund lands of Boyarka Forest Research Station

The relevance of the study is conditioned upon the predicted changes in the area, as well as the significant narrowing of the zone of optimal growth of Scots pine. These forecasts are based on obtaining data on the ongoing climate changes. A constant decrease in precipitation, along with a gradual increase in temperature levels, will lead to consequences such as uncontrolled changes in ecosystems. Such a substantial change in abiotic factors caused by human activity plays a key role in the formation of forest coenoses. The main purpose of this study was to analyse the change in the average annual temperature, as well as the monthly amount of precipitation observed in the forest communities in the Separated Subdivision of the National University of Life and Environmental Sciences of Ukraine “Boyarka Forest Research Station”. The analysis is performed over decades to obtain data on the level of temperature change in relation to the previous period. This also includes a comparison of monthly precipitation for 2021 relative to 1991-2020, which is set as normal. To obtain indicators of the average annual temperature, the average value method is used, followed by calculating the value of the average annual temperature for each decade. To find the deviation in total precipitation, the method of estimating the moisture conditions according to total precipitation is used. Therewith, the value of a substantial deviation is taken at 20% relative to the precipitation rate. According to the study results, it was established that in 2001-2010 the average annual temperature changed by 0.83°C relative to the previous decade, and in 2011-2020 by 0.74°C relative to the previous period. Such dynamics indicate a gradual increase in the average annual temperature, which is reflected in the forecasts of the world community. During the estimation of moisture conditions, separate months of 2021 with a critical level of precipitation in relation to the normal period were selected. In March, the amount of precipitation was 43% of normal, in June – 32%, in September – 40%, and in October – only 4.3% of normal. The value in November was observed at 63% of the norm. Such a decrease in the amount of precipitation in relation to a gradual increase in the average annual temperature poses a threat of a decrease in the hydrological level of moisture. This leads to a decrease in the radial increment of tree stands, and a gradual shift in the growing area of Scots pine. The obtained analysis results will further be used to conduct dendrochronological studies of tree rings of Scots pine (Pinus sylvestris L.) in the tree stands of the Separated Subdivision of the National University of Life and Environmental Sciences of Ukraine “Boyarka Forest Research Station”

Records of Anthropogenic Pollution in Silesia Captured in Scots Pine Tree Rings: Analysis by Radiocarbon, Stable Isotopes, and Basal Area Increment Analysis

Records of Anthropogenic Pollution in Silesia Captured in Scots Pine Tree Rings: Analysis by Radiocarbon, Stable Isotopes, and Basal Area Increment Analysis

How does varying water supply affect oxygen isotope variations in needles and tree rings of Scots pine?

In many regions, drought is suspected to be a cause of Scots pine decline and mortality, but the underlying physiological mechanisms remain unclear. Because of their relationship to ecohydrological processes, δ18O values in tree rings are potentially useful for deciphering long-term physiological responses and tree adaptation to increasing drought. We therefore analyzed both needle- and stem-level isotope fractionations in mature trees exposed to varying water supply. In a first experiment, we investigated seasonal δ18O variations in soil and needle water of Scots pine in a dry inner Alpine valley in Switzerland, comparing drought-stressed trees with trees that were irrigated for more than 10years. In a second experiment, we analyzed twentieth-century δ18O variations in tree rings of the same forest, including a group of trees that had recently died. We observed less 18O enrichment in needle water of drought-stressed compared with irrigated trees. We applied different isotope fractionation models to explain these results, including the Péclet and the two-pool correction, which considers the ratio of unenriched xylem water in the needles to total needle water. Based on anatomical measurements, we found this ratio to be unchanged in drought-stressed needles, although they were shorter. The observed lower 18O enrichment in needles of stressed trees was therefore likely caused by increased effective path length for water movement within the leaf lamina. In the tree-ring study, we observed lower δ18O values in tree rings of dead trees compared with survivors during several decades prior to their death. These lower values in declining trees are consistent with the lower needle water 18O enrichment observed for drought-stressed compared with irrigated trees, suggesting that this needle-level signal is reflected in the tree rings, although changes in rooting depth could also play a role. Our study demonstrates that long-term effects of drought are reflected in the tree-ring δ18O values, which helps to provide a better understanding of past tree physiological changes of Scots pine.

Climate Regimes Override Micro-Site Effects on the Summer Temperature Signal of Scots Pine at Its Northern Distribution Limits.

Tree growth at northern boreal treelines is generally limited by summer temperature, hence tree rings serve as natural archives of past climatic conditions. However, there is increasing evidence that a changing summer climate as well as certain micro-site conditions can lead to a weakening or loss of the summer temperature signal in trees growing in treeline environments. This phenomenon poses a challenge to all applications relying on stable temperature-growth relationships such as temperature reconstructions and dynamic vegetation models. We tested the effect of differing ecological and climatological conditions on the summer temperature signal of Scots pine at its northern distribution limits by analyzing twelve sites distributed along a 2200 km gradient from Finland to Western Siberia (Russia). Two frequently used proxies in dendroclimatology, ring width and maximum latewood density, were correlated with summer temperature for the period 1901–2013 separately for (i) dry vs. wet micro-sites and (ii) years with dry/warm vs. wet/cold climate regimes prevailing during the growing season. Differing climate regimes significantly affected the temperature signal of Scots pine at about half of our sites: While correlations were stronger in wet/cold than in dry/warm years at most sites located in Russia, differing climate regimes had only little effect at Finnish sites. Both tree-ring proxies were affected in a similar way. Interestingly, micro-site differences significantly affected absolute tree growth, but had only minor effects on the climatic signal at our sites. We conclude that, despite the treeline-proximal location, growth-limiting conditions seem to be exceeded in dry/warm years at most Russian sites, leading to a weakening or loss of the summer temperature signal in Scots pine here. With projected temperature increase, unstable summer temperature signals in Scots pine tree rings might become more frequent, possibly affecting dendroclimatological applications and related fields.

Age-Effect on Intra-Annual δ13C-Variability within Scots Pine Tree-Rings from Central Siberia

Intra-annual tree-ring parameters are increasingly used in dendroecology thanks to their high temporal resolution. To better understand the nature of intra-ring proxy signals, we compared old and young trees according to the different ways in which they respond to climate. The study was carried out in central Siberia (Russia, 60°75′ N, 89°38′ E) in two even-aged Pinus sylvestris L. stands of different ages (20 and 220 years). Ring width, cell size, and intra-annual δ¹³С were measured for 4 to 27 tree rings, depending on age group (young vs. old) and tree-ring parameter. Wood formation was monitored to link tree-ring position to its time of formation. Results indicated more distinct intra-annual δ¹³С patterns at both the beginning and end of the ring of young trees compared to old ones. Older trees showed a stronger significant correlation between δ¹³С across the ring border, indicating a stronger carry-over effect of the previous year’s growing conditions on current year wood production. This suggests that tree age/size influences the magnitude of the transfer of mobile carbon reserves across the years.

Tree ring wood density of Scots pine and European beech lower in mixed-species stands compared with monocultures

Mixed species stands are on the advance in Central Europe and many recently published studies have reported that they can overyield monocultures in terms of volume growth. However, as forest research has in the past been focused on monocultures, knowledge of how mixed-species stands and monocultures compare in terms of wood quality remains limited. Based on five triplets of fully stocked monocultures and mixed stands of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.), we analysed whether tree species mixing modifies wood quality and, more precisely, tree ring wood density.From a total of 322 trees we sampled increment cores for the analyses of tree ring width and tree ring wood density using a LIGNOSTATION™. We found that tree ring width of Scots pine was, on average, 14% wider in mixed compared with pure stands. Tree ring width of European beech did not differ between pure and mixed stands. Tree ring wood density was lower in mixed stands compared to pure stands for both Scots pine (−12%) and European beech (−8%). Tree ring wood density and tree ring width were negatively correlated in the case of Scots pine and positively correlated for European beech.When considering tree size and Stand density index, it was found that only tree ring width and mean tree ring wood density of European beech were influenced by stand density. Tree size had a significant effect only on tree ring wood density of European beech. The overall result of larger tree rings of Scots pine in mixed stands and a lower tree ring wood density of both species in mixed stands compared to pure stands was not influenced by stand density or tree size.Based on the measured values of tree ring wood density we conducted estimates of how mixed stands performed in terms of biomass. We found stem biomass to be 8% lower in mixed stands compared to pure stands. Reasons for the revealed differences in tree ring wood density and consequences for, among others, overyielding, carbon storage, and wood quality are discussed.

The history of mercury pollution near the Spolana chlor-alkali plant (Neratovice, Czech Republic) as recorded by Scots pine tree rings and other bioindicators

We assessed >100years of mercury (Hg) pollution recorded in the tree rings of Scots Pine near a Czech chlor-alkali plant operating since 1941. Hg concentrations in tree rings increased with the launching of plant operations and decreased when Hg emissions decreased in 1975 due to an upgrade in production technology. Similar to traditional bioindicators of pollution such as pine needles, bark and forest floor humus, Hg concentrations in Scots Pine boles decreased with distance from the plant. Mean Hg in pine bole in the 1940s ranged from 32.5μg/kg Hg at a distance of 0.5km from the plant to 5.4μg/kg at a distance of >4.7km, where tree ring Hg was the same as at a reference site, and other bioindicators also suggest that the effect of the plant was no longer discernible. Tree ring Hg concentrations decreased by 8–29μg/kg since the 1940s at all study sites including the reference site. The lack of exact correspondence between changes at the plant and tree ring Hg indicated some smearing of the signal due to lateral translocation of Hg from sapwood to heartwood. Bole Hg concentrations reflected local and regional atmospheric Hg concentrations, and not Hg wet deposition.

Scots pine tree ring structure modifications and relation with climate

In this study we assessed the tree ring structure modifications and the relation with climate in Scots pine from Aleșd region (Romania). Tree rings structures were analysed based on microscopic sections obtained from the core sample. The analysis on the area of the incomplete lignified cells (IC) and the lignified cells (CL) was made. The results show a high frequency of false rings, and unlignified cells. The tree ring with the highest unlignified cells part could be observed in the years 2007 and 1989. A reduced number of the unlignified cells were formed in the year 1998. An anomaly was analyzed in the tree ring structure of the year 1986. The temperature below 10 °C in the second period of the growing season has stopped the process of lignification of the wood cell walls. This study confirms the influence of temperature on the formation of the Scots pine tree rings. Key words: Scots pine, anatomical structure, radial growth, tree rings, temperature.

The application of potato starch effluent causes a reduction in the photosynthetic efficiency and growth of Scots pine (Pinus sylvestris L.)

The high concentration of N and K caused a weakening of physiological conditions of the trees. Application of N, P and K from starch effluent is not a suitable method of waste management. Since 1984, potato starch effluent has been applied to trees in the Ilawa Forest Inspectorate to promote the biological utilization of this waste product containing high amounts of nitrogen (N), phosphorus (P) and potassium (K). We examined the tree rings of Scots pine (Pinus sylvestris L.) to study the effect of intensive fertilization on tree rings. A total of 120 samples were taken from three sites representing a fertilized and unfertilized area and trees growing at a control site, outside the forest waste water system. We found that February and March temperature influenced the growth of tree rings. We used multiple regression to investigate the influence of N, P and K concentration, the amount of waste water and February and March temperature upon tree growth. Akaike information criterion (AIC) model selection was applied to choose the most influential factors upon growth, and additional multiple regression analyses were performed for two subsets of variables. Trees growing on the unfertilized site responded positively to N content and negatively to P content. For the fertilized site, the high concentration of N and K together with decreasing volume of waste water caused a growth decline. Trees from fertilized area also showed a decrease in their photosynthetic efficiency.

Influence of climate on Scots pine growth on dry and wet soils near Lake Engure in Latvia

INTRODUCTION The distribution of trees is generally determined by their ecological characteristics. Both internal and external factors, e.g. climate, influence the growth of trees. Many dendroclimatological studies have shown that climate explains a relatively large part of the temporal variability in tree-ring width (Fritts, 2001). The relationship between climate and tree-ring width occurs because plant growth is affected by specific conditions in the habitat environment. In addition, the nature of soil where trees grow may affect their response to climate (Linderholm, 2001; Linderholm et al., 2002; Vitas & Erlickyte, 2007; Weber et al., 2007). Scots pine (Pinus sylvestris L.) has a very wide ecological amplitude and successfully occupies dry habitats and sandy soils as well as peatland habitats. Therefore, it has a wider geographical distribution than any other pine species (Ohlson, 1995; Richardson & Rundel, 2000). Tree rings of Scots pine have been successfully used in dendroclimatology, mainly regarding trees growing on dry soils. Dendroclimatological investigations of tree rings in Latvia (Spalte, 1975, 1985; Skudra, 1982; Elferts, 2007a, 2007b), Lithuania (Bitvinskas, 1978; Vitas, 2004; Vitas & Erlickyte, 2007), Estonia (Laanelaid, 1982; Laanelaid & Eckstein, 2003), Poland (Cedro, 2001, 2006), and Scandinavia (Linderson, 1992; Linderholm, 2001; Linderholm et al., 2002) show that Scots pine growing on dry soil is sensitive to cold winters in the area around the Baltic Sea. Several studies treat the growth of Scots pine on peatlands. These have focused mainly on bogs and little is known about Scots pine growth on fens. Most of the previous studies examine relationships of pine growth on drained fens from a wood production improvement perspective (Pyateckij, 1963; Zalitis, 1967, 1968). There are only a few studies where the age and size of Scots pine as well as some habitat factors (nutrient characteristics of the peatlands and climate) are examined in relation to the natural regeneration of this tree species on fens (Agren et al., 1983; Ohlson, 1995). In pristine peatlands, e.g. fens, the most important differences in comparison to mineral soil sites are a high water table level (Boggie, 1972; MacDonald & Yin, 1999), poor soil aeration, and low nutrient availability and uptake, which control seedling survival (Agren & Zackrisson, 1990; Ohlson & Zackrisson, 1992; Sarkkola et al., 2004), and extremely slow growth of trees (Ohlson, 1995; MacDonald & Yin, 1999; Fritts, 2001; Hokka & Ojansuu, 2004). Water table depth is regulated by several factors, of which temperature and precipitation are the most important in controlling seasonal and yearly variation. This means that both of these factors influence tree growth directly and indirectly through regulation of the water table by evapotranspiration (Fritts, 2001; Linderholm et al., 2002). Climatic amelioration has been of great importance with regard to the comparatively successful regeneration of pine and spruce on peatlands (Agren et al., 1983). Ohlson (1995) observed that on fen sites the growth rate of Scots pine is greater and much more variable than on bog sites. Therefore, we suggest that Scots pine growing on fens can be more useful in dendroclimatology compared to pine growing on bogs. The aim of this study was to determine the climatic factors influencing the radial growth of Scots pine growing on dry and wet soils near Lake Engure in Latvia. MATERIAL AND METHODS Study sites Lake Engure is situated at the western coast of the Gulf of Riga, from which it is separated by a 1.5-2-km wide dune area. It is the largest relict lake in the coastal area of Latvia and has remained there since the time of the Litorina Sea (Viksne, 1997; Pakalne & Kalnina, 2005). It is a protected nature area, founded in 1957 as a restricted ornithological area (nowadays a nature park). …

Tree rings of Scots pine (Pinus sylvestris L.) as a source of information about past climate in northern Poland

Scots pine (Pinus sylvestris) is a very common tree in Polish forests, and therefore was widely used as timber. A relatively large amount of available wood allowed a long-term chronology to be built up and used as a source of information about past climate. The analysis of reconstructed indexed values of mean temperature in 51-year moving intervals allowed the recognition of the coldest periods in the years 1207–1346, 1383–1425, 1455–1482, 1533–1574, 1627–1646, and 1694–1785. The analysis of extreme wide and narrow rings forms a complementary method of examining climatic data within tree rings. The tree ring widths, early wood and late wood widths of 16 samples were assessed during the period 1581–1676. The most apparent effect is noted in the dry summer of 1616. According to previous research and our findings, temperature from February to March seems to be one of the most stable climatic factors which influenced pine growth in Poland. Correlation coefficients in the calibration and validation procedure gave promising results for temperature reconstruction from the pine chronology.

A critical evaluation of multi‐proxy dendroclimatology in northern Finland

AbstractTwentieth‐century summer (July–August) temperatures in northern Finland are reconstructed using ring widths, maximum density and stable carbon isotope ratios (δ13C) of Scots pine tree rings, and using combinations of these proxies. Verification is based on the coefficient of determination (r2), reduction of error (RE) and coefficient of efficiency (CE) statistics. Of the individual proxies, δ13C performs best, followed by maximum density. Combining δ13C and maximum density strengthens the climate signal but adding ring widths leads to little improvement. Blue intensity, an inexpensive alternative to X‐ray densitometry, is shown to perform similarly. Multi‐proxy reconstruction of summer temperatures from a single site produces strong correlations with gridded climate data over most of northern Fennoscandia. Since relatively few trees are required (<15) the approach could be applied to long sub‐fossil chronologies where replication may be episodically low. Copyright © 2010 John Wiley & Sons, Ltd.

Distribution of thallium and accompanying metals in tree rings of Scots pine ( Pinus sylvestris L.) from a smelter-affected area

Distribution of Tl, Zn, Cd, Pb, K, Ca, Mg and Mn and Pb isotopic composition in tree rings of Scots pine ( Pinus sylvestris L.) from an area affected by primary Zn smelting (Olkusz, southern Poland) were investigated. Elevated concentrations of Tl (up to 0.8 mg kg −1) in pine trees imply that conifers tend to accumulate this metal to some extent. A generally positive relationship between soil and tree-ring Tl levels was identified. The Tl patterns in stem wood did not correspond to changes in Tl deposition; the lateral translocation of Tl in the sapwood and its accumulation at the sapwood-heartwood boundary (i.e., in the inner sapwood) is suggested. It is probable that the specific behavior of Tl in trees results from its biogeochemical analogy with K. In contrast, tree-ring patterns of Zn and Cd significantly correlated with their deposition; nevertheless, a partial shift of these metals towards the stem center cannot be excluded. The isotopic composition of Pb ( 206Pb/ 207Pb ~ 1.172–1.184) in trees and underlying soils revealed the predominant influence of smelter emissions ( 206Pb/ 207Pb ~ 1.17) on Pb contamination. Analysis of main nutrients (Ca, Mg and Mn) in wood reflected environmental changes related to acid deposition.

CLIMATE SIGNAL IN THE RING WIDTH, DENSITY AND CARBON STABLE ISOTOPES IN PINE (PINUS SILVESTRIS L.) IN CENTRAL CAUCASUS

Variability of width, maximum density and stable isotopes ( δ 13 C) in tree-rings of Scots pine (Pinus sylvestris L.) were studied in Northern Caucasus. Statistically sufficient agreements between ring width chronologies allow to construct composite chronology for the Elbrus area. Absence or low correlation between indices of the ring width and maximum density chronology point out different climatic signal. The influence of temperature and precipitation on these tree-ring parameters was also analyzed. The ring width of pine at the upper tree limit in the Baksan valley correlates positively with the June and July precipitation (r=0.3; 0.3; 0.4, p<0.05). No correlation with temperature parameters was found. The maximum density reflects the warm period temperature (April-October). The similarity in interannual variations of δ 13 C in annual rings between the individual samples means that their display a coherent common signal. This signal can be largely interpreted as the June and July precipitation.

Centennial-to-millennial fluctuations in July temperatures in North Finland as recorded by timberline tree rings of Scots pine

A tree-ring proxy of summer temperature anomalies for northern Finland for the past 7500 yr was analyzed using Fourier spectrum and wavelet approaches. Multicentennial (250–450 yr) variability is present in the proxy record during most of the time range. This variability is suggested to reflect low-frequency variability in the North Atlantic Oscillation. Century-scale (90–130 yr) variation is another important feature of the tree-ring proxy data during the Holocene and may be attributed to Glessberg solar activity variations. In addition, an approximately 2000-yr quasi-period is found in this temperature proxy data, similar to the millennial-scale variability, present in many climate records from the North Atlantic region. The results point to the importance of multiple forcings underlying significant Holocene climatic fluctuations.

Reconstruction of summer temperatures from tree-rings of Scots pine (Pinus sylvestris L.) in coastal northern Norway

At the coast of northern Norway, 69°N, tree-ring chronologies from Scots pine (Pinus sylvestris L.) were constructed at Forfjorddalen in the Vesterålen archipelago (AD 1358-1992), Stonglandseidet on Senja (AD 1548-1994) and Vikran near Tromsø (AD 1700-1992). All chronologies reflect July-August temperatures. At the most northern site, Vikran, the response was more confined to July temperatures, resulting in a strong tree-ring and climate signal. The chronology from a steep, south-facing slope at Stonglandseidet showed signs of drought sensitivity. At the most oceanic locality, Forfjorddalen, mild winters appear to suppress tree growth on a decadal scale. Growth variations were consistent between the three sites for 1700-1910 but the amount of low-frequency variability decreased towards the most oceanic site. The seventeenth century, the coldest period of the ‘Little Ice Age’, experienced three cycles of summer temperatures, with minima around 1605, 1640 and 1680. An extended warm period occurred around 1475-1540. Temperature reconstruction showed secular trends similar to those observed east of the Scandes, but differed in the magnitude and timing of the extremes. At Forfjorddalen, there was no evidence of pine regeneration around 1575-1650. The latter site is likely to have been affected by logging activity in the seventeenth century.

Stable carbon isotopes in scots pine tree rings preserve a record of flow of the river Ob

Annual values of carbon isotope ratios for the period 1898–1990 are reported for Scots pine (Pinus sylvestris) growing in the valley of the lower river Ob in western Siberia. The data show highly significant inverse correlation to river flow over the period of instrumental records (1934–1990), although the strength of the relationship shows some dependence on the distance of the tree from the edge of the river. The predictive power of a linear regression model derived from the second half of the data set is validated by comparing the river flow for the first half of the period with values predicted by the model. Agreement is highly significant (r=0.80, P&lt;0.001). The results demonstrate the potential of carbon isotope ratios to predict river flow in this region.