Pine Chronology Research Articles

Hydrological variability of middle European peatland during the Holocene, inferred from subfossil bog pine and bog oak dendrochronology and high-resolution peat multiproxy analysis of the Budwity peatland (northern Poland)

Subfossil pine and oak tree trunks were excavated during exploitation of the Budwity peatland in Northern Poland. Based on dendrochronological analysis, the woodland successions in peatland were reconstructed and correlated with moisture dynamics of the peatland ecosystem inferred from the high-resolution multi-proxy analysis of the peatland deposits. From the results of dendrochronological analysis and the 14C wiggle matching methods, four floating pine chronologies (5882–5595; 5250–5089; 3702–3546; and 2222–1979 mod. cal BP) and two oak chronologies (4932–4599 and 4042–3726 mod. cal BP) were developed. The organic sediments of the peatland (6 m thick) were deposited over approximately nine thousand years. The lower complex (525–315 cm) comprises minerogenic peat, while the upper complex (315.0–0.0 cm) is composed of ombrogenic peat. Subfossil tree trunks are distributed across various peat horizons, which suggests multiple stages of tree colonisation followed by subsequent dying-off phases. Multiproxy sediment analyses (lithological, geochemical and δ13C stable isotope, pollen, plant macrofossils, Cladocera, diatom, and Diptera analyses) indicate that the two earliest phases of pine colonisation (5882–5595 and 5250–5089 mod. cal BP) and the two stages of oak colonisation (4932–4599 and 4042–3726 mod. cal BP) were associated with periodic drying of the peatland. Conversely, tree dying-off phases occurred during periods of increased water levels in the peatland, coinciding with stages of increasing climate humidity during the Holocene. The two most recent phases of pine colonisation occurred during the ombrogenic stage of mire development. Remnants of the dead forest from these phases, marked by subfossil trunks still rooted in the ground, were preserved and exposed presently during peat exploitation, approximately 2.5 m below ground level. The identified phases of tree colonisation and subsequent dying-off phases show correlation with analogical phenomena observed in the other investigated European peatlands.

Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan (Siberia)

Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan (Siberia)

ДЕНДРОКЛИМАТИЧЕСКИЙ АНАЛИЗ РАДИАЛЬНОГО ПРИРОСТА СОСНЫ ОБЫКНОВЕННОЙ В ЮЖНОЙ ТАЙГЕ НА ВОСТОЧНОЙ ОКРАИНЕ РУССКОЙ РАВНИНЫ

Regional dendroclimatological studies demonstrate the most accurate results when climatic responses of woody plantsto changes in climatic factors are identified in one particular region. Coniferous trees are the most frequent object of observation in suchstudies as they are more longevous and sensitive to changes in external factors. The paper presents the results of dendroclimatic investigation of growth variability of Scotch pine (Pinus sylvestris) growing in the southern taiga on the eastern edge of the Russian Plain. Chronology construction and data analysis were performed using CooRecorder, CDendro, COFECHA, ARSTAN and R programs. The obtainedtree-ring chronology of Scotch pine covers the time interval from 1822 to 2022, with a series duration of 201 years. The maximum growthwas observed in 1950 (1.21 mm), 1984 (1.25 mm), 2010 (1.37 mm). The minimum increment was in 1914 (0.75 mm), 1942 (0.77 mm),1977 (0.78 mm), and from 2015 to 2017. The analysis of correlation dependence of Scotch pine growth and climatic conditions showedthat the growth and development of the studied trees have been most influenced by changes in air temperature in June of the of the previousyear and current years, the correlation coefficient (R) is 0.068 and 0.156, respectively, as well as in October of the previous and currentyears - 0.352 and 0.221, respectively. The amount of precipitation has a smaller impact on growth. Thus, the factor of growth and development of Scotch pine on the eastern edge of the Russian Plain in the southern taiga subzone is mainly the air temperature in the fall monthsof the previous year and current year as well as the June temperature of the current year.

PHYTOPATHOLOGICAL MONITORING OF DANGEROUS OUTBREAKS DISEASE OF FOREST TREES WITH USE METHOD OF CHANGING RADIAL INCREMENTS IN THE CONDITIONS OF THE POLISKY NATURE RESERVE

PHYTOPATHOLOGICAL MONITORING OF DANGEROUS OUTBREAKS DISEASE OF FOREST TREES WITH USE METHOD OF CHANGING RADIAL INCREMENTS IN THE CONDITIONS OF THE POLISKY NATURE RESERVE

High resolution radiocarbon spike confirms tree ring dating with low sample depth

Radiocarbon (14C) has been used to date carbon-rich objects in Earth science, archeology, and history since the 1940s. New methods, using spikes in 14C caused by solar proton events, can be used to annually date wood when crossdating is not possible, such as when sample size is low, samples are floating in time, or external disturbances lead to insecure dates. Here, we use a spike in radiocarbon during a solar energetic particle (SEP) event in 774/775 CE to confirm crossdating of a poorly-replicated King Billy pine (Athrotaxis selaginoides) chronology. Low sample depth between 1498 and 1523 CE (two trees) prevented confident dating of the early period of the chronology. Three core samples with strong correlation with the master chronology that likely included the 774/775 CE Miyake SEP event were identified for radiocarbon isotope analysis. We sectioned segments centered on the estimated 774/775 CE date and then isolated the holocellulose in each sample. Samples were sent to an accelerator mass spectrometry (AMS) for radiocarbon measurements. The AMS data confirmed the crossdating accuracy of the tree ring series and reinforces the applicability of this technique to anchor poorly dated tree ring series in time. In addition, we found sample processing with a microtome proved superior for holocellulose extractions and yielded more accurate 14C measurements. We recommend sampling with a microtome, processing at least three samples per year, and including sample masses greater than 100 ug C to confirm dating using radiocarbon spikes.

Retracted: Two main temperature periodicities related to planetary and solar activity oscillations

AbstractThe mechanism and even the existence of the Atlantic Multidecadal Oscillation (AMO) have remained under debate among climate researchers, and the same applies to general temperature oscillations of a 60–90‐year period. The objective of this study is to show that these temperature oscillations are real and not artifacts and that these oscillations have different external cosmic origins. The authors have studied how well the variations of astronomical harmonic resonances (AHR) could explain the 60‐year temperature variations, which are based on instrumental records and on the tree‐ring data of the supra‐long Scots pine tree‐ring record for northern Finnish Lapland (subsequently called the Finnish timberline pine chronology [FTPC]), stretching to the year 5634 BC. Powerful volcanic eruptions have significant temperature‐decreasing impacts, and they are the major disturbances to eliminate in analysis. The similarities between the temperatures of the tree‐ring trend and the AHR trend are easy to observe even by the naked eye. The statistical analysis shows that these two signals are statistically related. The analyses also show that the well‐known Gleissberg cycle of 88 years is the dominating cycle caused by the Suns' activity changes but the observed 60‐year cycle can be connected to the AHR cyclicity.

Dendroclimatic signals in the pine and spruce chronologies in the Solovetsky Archipelago

Searching for a robust tree-ring parameter useful for paleoclimatic purposes is one of the most demanding topics in the modern paleoscience. Since Blue Intensity has already expressed itself in different geographical locations all over the world as a possible replacement for maximum density, close attention is paid to investigate features of the inferred signal. The Solovki Islands is a unique location in Northern Russia where two important factors that make this territory attractive for developing a long tree-ring chronology have been met: modern long-living trees and building activities using old trees that were started by monks in the middle of the 16th century. The main goal of the research is to develop pine and spruce chronologies based on tree-ring width (TRW) and delta Blue Intensity (dBI) and to assess the ability of these parameters to be used as climate predictors. As a result, 14 conifer chronologies from 7 sites (4 for pine and 3 for spruce) were developed. The composite pine and spruce chronologies span a period of 474 and 378 years each. Cross-correlation of dBI-based chronologies of both conifers is high (r = up to 0.71 while for TRW-based chronologies it is lower on average (−0.18 to 0.63). Intra-species correlation of TRW chronologies in some cases achieved even negative values (r = −0.18. Discrepancies found between TRW chronologies of pine and spruce could be explained by differences in climatic signals. Response function analysis with monthly temperatures revealed that growth of pine depends on the previous August, while spruce has a temporally stable and strong relation to June temperatures. Compared to TRW, dBI-based chronologies have a high correlation with summer temperatures (r = 0.64 and 0.66 for spruce and pine, respectively). Presented research points out the importance of the response function analysis suggesting that depending on goals of the study several tree-ring parameters could be used, e.g., tree-ring width of spruce responses to June temperatures, while dBI to the whole summer.

Pre-monsoon drought variability in the southeastern Loess Plateau over the past 246 years

In recent decades, the Loess Plateau has experienced drying that has had a massive influence on society, ecosystems, and agriculture. However, the limited availability of observed climate data hampers the assessment of continuous drying. In this study, we present a robust tree-ring-width chronology of Chinese Pine with which we reconstructed the pre-monsoon self-calibration Palmer Drought Severity Index (scPDSI) for the last 246 years. The reconstruction is derived from cores sampled from two sites over the southeastern Loess Plateau, is reliable and stable, and explains 54.9% of the variance of observed scPDSI over the period 1957–2017. Our reconstruction reveals obvious annual and decadal variations, with an uneven temporal distribution of dry and wet years. Our reconstruction documents the ongoing drying in recent decades. The period from 2000 to 2018 was the driest over the last 246 years, as according to the 11-year moving average series, five of the top ten most severe droughts occurred during this period. Results of spatial correlation analysis and composite analysis suggest that the North Atlantic sea surface temperature may influence pre-monsoon drought variation over the southeastern Loess Plateau by influencing the westerly jet, the height field, and atmospheric vertical motion.

Usporedna analiza utjecaja klimatskih čimbenika na radijalni rast autohtonih vrsta borova (Pinus spp.) u središnjoj Bosni i Hercegovini

In central Bosnia and Herzegovina, in the Zavidovići-Teslić area, the study of the radial growth of Austrian and Scots pine (autochthonous pine species) trees was conducted using the dendrochronological method in order to identify the differences between the species in terms of the influence of climatic variables on the tree ring formation. Trees were sampled in five experimental areas or five sites. The first site had a Scots pine stand, while the second had an Austrian pine stand, and the other three sites had mixed stands of Scots and Austrian pine. Cross-dating was conducted using visual on-screen techniques of CDendro software and statistical methods using Cofecha software. The tree ring series were standardized using the Arstan program and cubic smoothing spline. It produced Scots pine regional chronology, 145 years long (1870-2014), and Austrian pine regional chronology, 180 years long (1835-2014). Correlation analysis of the relationship between the index of tree-ring width and precipitation and temperature in the characteristic periods of the year showed a negative effect of temperature (except in winter months) and a positive effect of precipitation on the tree ring formation. The statistically significant dependence of the tree-ring width index on the SPEI indices indicates a significant impact of moisture deficiency on the tree ring formation in the period from June to August (r = 0.33 in June, r = 0.45 in July and r = 0.47 in August) for Scots pine and in the period from June to September (r = 0.36 in June, r = 0.43 in July, r = 0.47 in August and r = 0.30 in September) for Austrian pine. The analysis of the relationship between climatic parameters and the chronologies of Scots and Austrian pine shows similar relationships between radial growth and climate but the influence of climate is somewhat more pronounced in Austrian pine. In the study area, the radial growth of both tree species is significantly determined by climate conditions. In other words, the chronology of these species has a good climatic signal, especially the drought signal in the summer months.

Climate drove the fire cycle and humans influenced fire occurrence in the East European boreal forest

AbstractUnderstanding long‐term forest fire histories of boreal landscapes is instrumental for parameterizing climate–fire interactions and the role of humans affecting natural fire regimes. The eastern sections of the European boreal zone currently lack a network of annually resolved and centuries‐long forest fire histories. To fill in this knowledge gap, we dendrochronologically reconstructed the 600‐year fire history of a middle boreal pine‐dominated landscape of the southern part of the Republic of Komi, Russia. We combined the reconstruction of fire cycle (FC) and fire occurrence with the data on the village establishment and climate proxies and discussed the relative contribution of climate versus human land use in shaping historic fire regimes. Over the 1340–1610 ce period, the territory had a FC of 66 years (with the 90% confidence envelope of 56.8 and 78.6 years). Fire activity increased during the 1620–1730 ce period, with the FC reaching 32 years (31.0–34.7 years). Between 1740–1950, the FC increased to 47 years (41.9–52.0). The most recent period, 1960–2010, marks FC's historic maximum, with the mean of 153 years (102.5–270.3). Establishment of the villages, often as small harbors on the Pechora River, was associated with a non‐significant increase in fire occurrence in the sites nearest the villages (p = 0.07–0.20). We, however, observed a temporal association between village establishment and fire occurrence at the scale of the whole studied landscape. There was no positive association between the former and the FC. In fact, we documented a decline in the area burned, following the wave of village establishment during the second half of the 1600s and the first half of the 1700s. The lack of association between the dynamics of FC and the dates of village establishments, and the significant association between large fire years and the early and latewood pine chronologies, used as historic drought proxy, indirectly suggests that the climate was the primary control of the landscape‐level FCs in the studied forests. Pine‐dominated forests of the Komi Republic may hold a unique position as the ecosystem with the shortest history of human‐related shifts in fire cycles across the European boreal region.

BOG PINE AND DECIDUOUS TREES CHRONOLOGIES RELATED TO PEAT SEQUENCES STRATIGRAPHY OF THE PODEMSZCZYZNA PEATLAND (SANDOMIERZ BASIN, SOUTHEASTERN POLAND)

ABSTRACTThe Podemszczyzna peatland (Sandomierz Basin, SE Poland) is a place of peat exploitation for balneological purposes. The thickness of organic sediments (minerogenic peat) reaches 4.0 m, while the beginning of peat accumulation was dated using the radiocarbon method (14C) at 13,517–13,156 cal BP. During the peat exploitation numerous fragments of subfossil wood (of various species) were excavated and, based on dendrochronological analyzes and 14C dating (wiggle-matching), two short floating chronologies were elaborated: bog pine chronology (147 years long) and deciduous trees (oak, elm) chronology (139 years long). 14C dating has shown that the bog pine chronology (ca. 9980–9830 mod. cal BP) is the oldest pine chronology found in the Polish peatlands so far. It was synchronous with the Preboreal decline of fluvial activity and peat formation, whereas dying off of trees was connected with distinct rise of fluvial activity. Floating chronology of deciduous trees is much younger and encompasses time interval of ca. 680–545 cal BP. The trees’ encroachment on the peatland was related to the terrestrialization of the depositional fen, recorded in the loss on ignition curve in the form of mineral sediment delivery to the bog, as well as it is marked in the pollen record.

Centennial Scots pine chronologies for western, central and eastern Lithuania

Although two centennial Scots pine chronologies for the dating of timber in Lithuania were constructed in the 2000 s, the Baltic countries still lack a network of regional chronologies. To fill this gap, we constructed three Scots pine chronologies for western, central and eastern Lithuania. Here we present chronologies covering the fifteen to the twentieth centuries. Our analysis revealed a strong teleconnection of the compiled chronologies with Scots pine chronologies constructed in Poland, Latvia, Estonia, and Belarus. The established link with Belarus chronologies and the fact that some of the timber in Lithuanian buildings could be of Belarus origin is important in the long-distance timber trade during the last 500 years. Dendroclimatological analysis has shown that constructed tree-ring chronologies are sensitive to air temperatures in February and March. Therefore, the constructed chronologies have a potential for climate reconstructions and dendroprovenancing.

Discovering the Unknown History of the Utilization of Pinus heldreichii in Wooden Structures by Means of Dendroarchaeology: A Case Study from Metsovo (Northern Greece)

(1) Background: Pinus heldreichii is a long-living tree subalpine species commonly used for climate reconstruction. Nevertheless, its potential for dendroarchaeology and dating of historical timber remains unknown. In Metsovo and in the surrounding area of Pindus National Park (Northern Greece) it is commonly used for the construction of buildings and wooden objects and artifacts. (2) Methods: We examined timber found in historical buildings within the study area and we tried to date it using local reference chronologies of Bosnian and Black pines. (3) Results: Bosnian pine chronologies can be used to date timber from historical buildings, while they can also be used as reference chronologies against Black pines, giving very high cross-dating values. Therefore, and since the macroscopic identification of the two species’ timber is impossible, the analysis of wood anatomy is necessary to distinguish the two species in the case of historical wood. (4) Conclusions: The current paper presents the first application of dendroarchaeology for Bosnian pine and highlights the potential of the species in studying cultural heritage and the human past.

Is tree ring chronology of blue pine (Pinus wallichiana A. B. Jackson) prospective for summer drought reconstruction in the Western Himalaya?

• Tree ring chronology of blue pine is potential for long term SPEI (drought index) reconstruction. • Provides a reliable drought records (322-year’s) during monsoon season of the western Himalaya. • The spectral peaks (2–4 years) indicate drought fluctuations are linked mostly to ENSO events. • The reconstructed monsoon SPEI showed notable drying towards 1990 to 2017AD. A long record of drought beyond observable data is scarce in the Himalayan region, making it difficult to understand the region's long-term variability. Here we reconstructed the Standardized Precipitation Evapotranspiration Index (SPEI) a drought index using the tree-ring chronology of blue pine ( Pinus wallichiana ), to retrieve the past drought variations. The chronology is prepared from tree ring width series of well replicated samples of blue pine covering time span of 1660–2017 CE, from Darma Valley, Indian Western Himalaya. We observed that the combined expression of precipitation and temperature, conveyed as SPEI, is more effective in limiting tree growth during the monsoon season than either precipitation or temperature alone. The SPEI of June-September (monsoon season) exhibited a significant strong positive correlation (r = + 0.69, p < 0.001) with the tree ring chronology. Based on this relationship, we reconstructed monsoon SPEI covering 1696–2017 CE. The variance explained for the calibration period 47% of the actual SPEI variance of 1903–2017 CE. The extended SPEI time series indicates several high and low intensity droughts, which are consistent with the historical drought records of the Himalayan region. Furthermore, analyses of the spatial correlations reveal that the variation in the reconstructed monsoon SPEI is strongly associated with the regional summer drought variability in the Himalayan region. We recorded a strong teleconnection of SPEI data and sea surface temperature changes in the Indian and Pacific Oceans, indicating that Indian summer monsoon variability is prevalent for this region's summer monsoon SPEI. Furthermore, in the spectral analysis peaks between 2.0 and 4.0 years indicates that the summer drought fluctuation is linked to El Niño-Southern Oscillation (ENSO).

Intra-annual ring width and climate response of red pine in Itasca State Park in north-central Minnesota

Red pine (Pinus resinosa Ait.) of northern Minnesota are part of a growing network of tree-ring chronologies aimed at understanding climate dynamics in the Upper Great Lakes Region. Red pine has been widely used in tree-ring studies of fire and climate variability across its range. Earlier studies have relied primarily on total annual ring width. Here we develop annual and subannual (i.e., earlywood, latewood, and adjusted latewood) chronologies from Itasca State Park to refine our understanding of red pine climate response. Our chronologies extend to the early 18th century and display common growth and cross-dating characteristics indicative of a significant common controlling mechanism. We found that total ring width contains dampened attributes reflective of both the temperature-limited earlywood and moisture-dependent latewood chronologies. The strongest relationship between climate and radial growth is between the adjusted latewood chronology and 3-month summer precipitation, suggesting that overall summer wetness rather than any single summer month primarily limits growth. The ability to disaggregate and improve upon the mixed climate signal of red pine highlights the potential of using intra-annual chronologies to strengthen future climate reconstructions. We hope the methodologies demonstrated here serve as a potential guide for future red pine chronology development in the region.

A half-millennium perspective on recent drying in the eastern Chinese Loess Plateau

Northern China has experienced dramatic drying since the 1960s CE. However, the scarcity of long-term observations hampers the evaluation of recent drought variations from a long-term perspective. Here, we present a tree-ring-width chronology of Chinese pine (Pinus tabuliformis Carr.) from the eastern edge of the Chinese Loess Plateau (ECLP), which is the longest tree-ring chronology on the ECLP (1535–2018 CE). This chronology was used to reconstruct the average April-June self-calibrated Palmer Drought Severity Index (scPDSI). The reconstruction explains 64.3% of the variations in the observed scPDSI during the calibration period (1954–2000 CE). The driest and wettest years over the full reconstruction were 1759 CE and 1649 CE, respectively. The two most prolonged drought intervals occurred in 1892–1943 CE and 1737–1775 CE, while the two most prolonged pluvial intervals occurred in 1950–1992 CE and 1645–1682 CE. The reconstruction captures the recent drying since the 1960s. However, we found that the recent notable drying is not unprecedented over the last half-millennium, as more dramatic drought fluctuations occurred around the 1650s-1690s. The spatial correlation with sea surface temperature (SST) indicates that the drought variations on the ECLP might be modulated by the North Atlantic SST tripolar pattern. This study provides a reference for long-term drought evaluation, which may have implications for drought prediction and adaptation on the ECLP.

The Influence of the Forest Factors on the Variability of the Tree-ring Chronologies of the common Pine in the conditions of the Muromtsevo District Forestry of the Vladimir Region

Comparative analysis of tree-ring chronologies on the variability of the short-term component is based on the calculation of synchronicity coefficients. The study of the regularities of the variability of tree-ring chronologies on this basis in natural cenopopulations is important for establishing the reaction rate of this indicator. This is significant for the further progress of dendrochronological and dendroclimatic studies, improving the methods of forensic botanical examination using dendrochronology methods. In the study, this issue was studied on the basis of chronologies from different phytocenoses with the predominance of scots pine in the stand. The trial areas were located on the territory of the Muromtsevo forestry of the Vladimir region. The study was carried out as part of the implementation of R&amp;D Rosleskhoz (2008-2011). The main parameters of the frequency of occurrence of different variants of the values of the synchronicity coefficient were established. The regularities of the frequency of occurrence of different values of the synchronicity coefficient depending on the type of forest are also established: The range of variation of values between groups from different types of forest is small and amounts to several percent. The data obtained are important for solving the following practical tasks: monitoring the accuracy of measurements of annual rings on individual wood samples; establishing the date of termination of cambial activity in the trunk of a tree; establishing the date of construction of wooden buildings; dating of archaeological wood; dating the time of creation of art objects; diagnostics of the condition of the tree at the time of cutting; establishing the time of cutting the tree; establishing the drying time a tree.

Past millennium hydroclimate variability from Corsican pine tree‐ring chronologies

Palaeoclimatic evidence is necessary to place the current warming and drying trends of the Mediterranean region in a long‐term perspective of pre‐industrial variability. Annually resolved and absolutely dated climate proxies that extend back into medieval times are, however, limited to a few sites only. Here we present a network of long ring width chronologies from Pinus nigra tree‐line sites in northern Corsica (France) that cohere exceptionally well over centuries and support the development of a single high‐elevation pine chronology extending back to 974 CE. We apply various detrending methods to these data to retain high‐to‐low frequency ring width variability and scale the resulting chronologies against instrumental precipitation and drought observations to produce hydroclimate reconstructions for the last millennium. Proxy calibration and transfer are challenged by a lack of high‐elevation meteorological data, however, limiting our understanding of precipitation changes in sub‐alpine tree‐line environments. Our new reconstructions extend beyond existing records and provide evidence for low‐frequency precipitation variability in the central‐western Mediterranean from 974–2016 CE. Comparison with a European scale drought reconstruction network shows that regional predictor chronologies are needed to accurately estimate long‐term hydroclimate variability on Corsica.

THE EFFECT OF CLIMATE ON RADIAL GROWTH OF SCOTS PINE (Pinus sylvestris L.) IN A COASTAL MIXED STAND IN KAPISUYU, BARTIN, TURKEY

Scots pine is geographically the most widespread pine species in the world, and it shows different growth responses to climate and environmental factors in diverse ecological sites. We studied both the stand dynamics and climate-growth relationships of scots pine in isolated coastal stand (recently found) in the Western Black Sea Region of Turkey. The homogeneity index of this stand has varied between 1.92–3.56. In growth-ring analyses, after cross-dating of individual chronologies, COFECHA and ARSTAN software were used respectively for chronology quality control and standardization (detrend). In this way, a 58-year-long chronology (1959-2016) of scots pine was constructed. In addition, DENDROCLIM software was used for investigating scots pine’s radial growth-climate relationships. Mean sensitivity changed from 0.163 to 0.331, with a mean of 0.183. Mean correlation among trees and signal to noise ratio were 0.389 and 7.012 respectively. In terms of the effect of precipitation on the radial growth of scots pine in this site, the correlation coefficients were 0.43 (p&lt;0.05) for December of the previous year and 0.41 (p&lt;0.05) for July of the current year. For all the other months, precipitation had a non-significant effect. As for the maximum and mean air temperature, the correlation coefficients were 0.36 (p&lt;0.05) and 0.40 (p&lt;0.05) for February, and 0.40 (p&lt;0.05) and 0.42 (p&lt;0.05) for March, respectively. However, on the radial growth, while the maximum temperature in August had a negative effect (r= -0.26; p&lt;0.05), minimum temperatures in February, March and July had a positive effect (r= 0.39, 0.40 and 0.34 respectively; p&lt;0.05).

THE EFFECT OF CLIMATE ON THE RADIAL GROWTH OF SCOTS PINE (PINUS SYLVESTRIS L.) IN A COASTAL MIXED STAND IN KAPISUYU, BARTIN, TURKEY

Scots pine is geographically the most widespread pine species in the world, and it shows different growth responses to climate and environmental factors in diverse ecological sites. We studied both the stand dynamics and climate-growth relationships of Scots pine in isolated coastal stand (recently found) in the Western Black Sea Region of Turkey. The homogeneity index of this stand has varied between 1.92-3.56. In growth-ring analyses, after cross-dating of individual chronologies, COFECHA and ARSTAN software were used respectively for chronology quality control and standardization (detrend). In this way, a 58-year-long chronology (1959-2016) of Scots pine was constructed. In addition, DENDROCLIM software was used for investigating Scots pine’s radial growth-climate relationships. Mean sensitivity changed from 0.163 to 0.331, with a mean of 0.183. Mean correlation among trees and signal to noise ratio were 0.389 and 7.012 respectively. In terms of the effect of precipitation on the radial growth of Scots pine in this site, the correlation coefficients were 0.43 (p&lt;0.05) for December of the previous year and 0.41 (p&lt;0.05) for July of the current year. For all the other months, precipitation had a non-significant effect. As for the maximum and mean air temperature, the correlation coefficients were 0.36 (p&lt;0.05) and 0.40 (p&lt;0.05) for February, and 0.40 (p&lt;0.05) and 0.42 (p&lt;0.05) for March, respectively. However, on the radial growth, while the maximum temperature in August had a negative effect (r= -0.26; p&lt;0.05), minimum temperatures in February, March and July had a positive effect (r= 0.39, 0.40 and 0.34 respectively; p&lt;0.05). It means while higher rains in July and higher temperatures in the late winter-early spring have caused the wider growth rings, the narrower growth rings have been formed in the years with higher maximum temperatures in August in the isolated coastal site of Scots pine.