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Tree-ring chronologies based on the annual ring width of Scots pine (Pinus sylvestris L.) have been studied at eight test sites in insular pine forests in the north of the Republic of Kazakhstan from the Turgay Depression to the eastern part of the Kazakh Uplands. Analysis of the relationships between radial increment of pine and climate shows that the climatic signal in the chronologies can change depending on geomorphological conditions caused by the edaphic factor, relief, and absolute elevation marks. These features must be taken into account when using tree-ring chronologies for spatiotemporal reconstructions of climate. [ABSTRACT FROM AUTHOR]

The influence of meteorological factors and anthropogenic air pollution on the radial growth of the Scots pine Pinus sylvestris L. was studied as dependent on the distance from the Pechenganickel mining and metallurgical plant (Nikel, Murmansk region). Three (control, buffer, and impact) zones of the pollution gradient were identified based on the contents of main polluting elements (S, Ni, and Cu) in the forest litter. A significant weakening of pine stands was observed in the impact zone and attributed to the combined effect of long-term anthropogenic pollution of the 1970s and unfavorable weather events of the mid-1980s. As the emission decreased from 1988 to 2018, the radial increment of P. sylvestris was observed to increase significantly (by up to 44%) in the impact zone and to remain much the same in the control and buffer zones. More recently, the radial increment of trees in the impact zone reached and even exceeded the values observed in the control zone, although the trees examined were relatively old. The finding demonstrated again the high adaptive capacity of P. sylvestris. [ABSTRACT FROM AUTHOR]

The purpose of this study is a comparative analysis of linear and radial increments of Scots pine (Pinus sylvestris L.) as a response to the growing conditions on the coast of the Kandalaksha Bay of the White Sea, as well as an evaluation of the temperature and precipitation influences of the current and previous growing seasons. These were applied to the conventional methods of measurement and data analysis. The dynamics of growth in height and diameter were employed as indicators of the stands' response to habitant conditions. A statistical analysis of the growth rates was performed, which vary depending on habitat type, as well as an assessment of the connection between biometric indicators of the stands and the amount of precipitation and mean temperature. The significant differences in the series of linear increment increases were found as distinctions between biotopes, but they were absent for the radial increment. Therefore, it is possible to monitor the typical behavior of tree diversity independent of the biotope type using radial growth series. This provides the foundation for a long-term retrospective analysis of environmental impact on the stands by using the annual rings of the trees without taking growing conditions into account. Precipitation was determined to be a limiting factor for radial and linear growth throughout the phenophase of internodal growth and early wood formation. Temperature was identified as a limiting factor for radial development only during the stages of late wood formation and resource accumulation for the following growing season. The high sensitivity of linear increases to climatic conditions was revealed, which makes it useful as a criterion for assessing the state of forest ecosystems over short time periods (up to 30 years). However, this, in turn, dictates the impossibility of forming long-term linear increment series, as for radial growth, which is a significant limitation of this method. The choice of linear or radial growth analysis methods is concluded to be determined by the goals of the intended study, i.e., monitoring forest ecosystems under current climate change conditions or long-term paleoclimate analysis. For citation: Koukhta A.E., Maksimova O.V., Kuznetsova V.V. Influence of Climatic Factors on Scots Pine (Pinus sylvestris L.) Growth on the Coast of the Kandalaksha Bay of the White Sea. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 105–119. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-105-119

Radial increment objectively reflects the quality of the assimilation apparatus of a woody plant. Its features indicate the influence of various anthropogenic, biotic and abiotic factors as well as the stability of the plant under stress. The aim of this study was to survey the long-term dynamics of the radial growth of six tree species: Betula pendula, Ulmus glabra, Quercus robur, Tilia cordata, Picea abies and Pinus silvestris, depending on the impact of creating a reservoir and the fluctuations of the water level in it. Additionally, another aim was to determine whether there is a dependence between the annual radial increment of these tree species and the change in the temperature factor during the growing season. We studied cores of trees growing in a park on the coast of the Sheksna river, the level of which is regulated by the water level in the Rybinsk Reservoir and changes along with it. This research presents the dynamics of the annual radial growth of Betula pendula over 59 years, Ulmus glabra over 50 years, Quercus robur over 59 years, Tilia cordata over 82 years, Picea abies over 128 years and Pinus silvestris over 125 years. The average annual radial growth decreases in the series Ulmus glabra > Betula pendula, Quercus robur > Tilia cordata > Picea abies > Pinus silvestris. The radial increase does not correlate with the annual water level in the Rybinsk Reservoir. However, years with extreme minimum and maximum reservoir filling affect the radial growth of Quercus robur (r = 0.56) and Tilia cordata (r = 0.52). It was found that after the creation of the reservoir, the radial increment of Picea abies was significantly reduced by 1.10 mm. The clearest dependence of ring width index was obtained for Picea abies on temperature in May (r = −0.30 at p ≤ 0.05) and for Pinus sylvestris on temperature in July (r = −0.25 at p ≤ 0.05). Similarly, a weak correlation of ring width index with temperature in some months was noted for deciduous trees. Picea abies is notable for its particular display of moderate inverse correlation to the radial growths of other trees.

This article presents the results of a comparative analysis of the radial increment of various larch species and provenances growing on a common ecological background in experimental forestry established in 1965–1967 on the Krasnoyarsk forest steppe by employees of the Sukachev Institute of Forest, Siberian Branch, Russian Academy of Sciences. The provenances of Siberian larch (Larix sibirica Ledeb.) from different elevation belts of the Southern Siberian Mountains, Gmelin larch (L. gmelinii Rupr.) from the Trans-Baikal and Zeya provinces (Eastern Siberia), and Japanese larch (L. leptolepis Gord) introduced from the island of Sakhalin are studied. Based on the cluster analysis of radial increment series, four groups of provenances are identified with different growth strategies, depending on the response to environmental factors: mountain–forest steppe and mountain–taiga provenances of Siberian larch and provenances of Gmelin larch from Transbaikalia. The provenance of Japanese larch from Sakhalin has formed a separate cluster. The highest values of radial increment are found in groups of mountain–forest-steppe provenances formed by Siberian larch and Gmelin larch trees introduced from East Siberian provinces. Low values of radial increment are noted in provenances of Siberian larch trees from Southern Siberia mountain–taiga zone and Japanese larch from Sakhalin. Dendroclimatic analysis is used to identify the relationship between the environmental variables of the introduction zone and the radial increment of the studied provenances. In the Krasnoyarsk forest steppe, the main factor limiting radial increment is the moisture content of the root layer in the middle of the growing season (July–August). Larch trees introduced from wetter habitats respond more strongly to an increase in water stress, while the radial increment of trees taken from drier habitats responds positively to an increase in the length of the growing season. [ABSTRACT FROM AUTHOR]

Teak has been planted extensively by smallholders in Central America within reforestation programmes and has become one of the most valuable timbers. The five-year growth and mortality of teak cultivated in a plantation in central Nicaragua, representing sites at the low limit of teak ecological valence, were evaluated. From 2006 to 2010, 72 pure teak stands were established, with 48.93 ha in total. For afforestation, planting stock from five provenances was used and planted at 1 m × 1 m spacing to stimulate the height growth and reduce broad crowns formed by self-pruning. In the pure teak stands, 144 permanent sample plots of 0.01 ha in size were established in 2011. From 2011 until 2015, the tree height and stem girth of all individuals in the studied sample plots were measured, and mortality based on the stand density was assessed. Significant differences between the provenances were observed. The highest growth was noted in the Local provenance originated from the studied area, whereas the Semilla provenance from Costa Rica, characterised by the lowest growth ability, was characterized by lower radial increment and mean tree height with high mortality.

Radial increment objectively reflects the quality of the assimilation apparatus of a woody plant. Its features indicate the influence of various anthropogenic, biotic and abiotic factors as well as the stability of the plant under stress. The aim of this study was to survey the long-term dynamics of the radial growth of six tree species: Betula pendula, Ulmus glabra, Quercus robur, Tilia cordata, Picea abies and Pinus silvestris, depending on the impact of creating a reservoir and the fluctuations of the water level in it. Additionally, another aim was to determine whether there is a dependence between the annual radial increment of these tree species and the change in the temperature factor during the growing season. We studied cores of trees growing in a park on the coast of the Sheksna river, the level of which is regulated by the water level in the Rybinsk Reservoir and changes along with it. This research presents the dynamics of the annual radial growth of Betula pendula over 59 years, Ulmus glabra over 50 years, Quercus robur over 59 years, Tilia cordata over 82 years, Picea abies over 128 years and Pinus silvestris over 125 years. The average annual radial growth decreases in the series Ulmus glabra > Betula pendula, Quercus robur > Tilia cordata > Picea abies > Pinus silvestris. The radial increase does not correlate with the annual water level in the Rybinsk Reservoir. However, years with extreme minimum and maximum reservoir filling affect the radial growth of Quercus robur (r = 0.56) and Tilia cordata (r = 0.52). It was found that after the creation of the reservoir, the radial increment of Picea abies was significantly reduced by 1.10 mm. The clearest dependence of ring width index was obtained for Picea abies on temperature in May (r = −0.30 at p ≤ 0.05) and for Pinus sylvestris on temperature in July (r = −0.25 at p ≤ 0.05). Similarly, a weak correlation of ring width index with temperature in some months was noted for deciduous trees. Picea abies is notable for its particular display of moderate inverse correlation to the radial growths of other trees. [ABSTRACT FROM AUTHOR]

Teak has been planted extensively by smallholders in Central America within reforestation programmes and has become one of the most valuable timbers. The five-year growth and mortality of teak cultivated in a plantation in central Nicaragua, representing sites at the low limit of teak ecological valence, were evaluated. From 2006 to 2010, 72 pure teak stands were established, with 48.93 ha in total. For afforestation, planting stock from five provenances was used and planted at 1 m × 1 m spacing to stimulate the height growth and reduce broad crowns formed by self-pruning. In the pure teak stands, 144 permanent sample plots of 0.01 ha in size were established in 2011. From 2011 until 2015, the tree height and stem girth of all individuals in the studied sample plots were measured, and mortality based on the stand density was assessed. Significant differences between the provenances were observed. The highest growth was noted in the Local provenance originated from the studied area, whereas the Semilla provenance from Costa Rica, characterised by the lowest growth ability, was characterized by lower radial increment and mean tree height with high mortality. [ABSTRACT FROM AUTHOR]

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is a non-native tree species in Slovenia with the potential to partially replace Norway spruce in our native forests. Compared to spruce, it has several advantages in terms of volume growth, wood quality and tolerance to drought. This is important given the changing climate in which spruce is confronted with serious problems caused by increasing temperatures and drought stress. At three sites (one on non-carbonate bedrock and deep soils, and two on limestone with soil layers of varying depths), 20 Douglas-fir and 20 spruce per site were sampled in order to compare their radial growth response to climate and drought events. The radial growth of Douglas-fir exceeds that of spruce by about 20% on comparable sites. It is more responsive to climate than spruce. Above-average temperatures in February and March have a significant positive effect on the radial growth of Douglas-fir. In recent decades, above-average summer precipitation has also had a positive influence on the radial growth of Douglas-fir. Compared to spruce, Douglas-fir is less sensitive to extreme drought events. Our results indicate that Douglas-fir may be a good substitute for spruce in semi-natural managed forest stands in Slovenia. The planting of Douglas-fir should be allowed in Slovenian forests, but the proportion of it in forest stands should be kept lower than is the case with spruce today. [ABSTRACT FROM AUTHOR]

Research has been carried out to study the effect of the first thinning on the overall productivity of mature pine stands in the forest-steppe zone of the Krasnoyarsk Kray. The results of the influence of felling from low to very high volume intensity on the value of the current periodic growth in mature pine stands of different initial basal area are presented. In pine forests of forb-green moss and lingonberry-forb-green moss types, a comparative analysis of the average annual periodic increase in the stock for 5–10 years was carried out. It was found that the increase is due to both the intensity of felling and the initial density of stands and varies within wide limits (from 2.4 to 7.3 m3/ha per year). On control plot, this value was 2.6–4.9 m³/ha per year. A positive dependence of the average current annual increment per 1 m3 of stand volume after the first thinning with the felling intensity was revealed. Thinning intensity optimums were determined for stands of different initial density at the age of 100–120 years. For initial densities of 500, 600, 700 and 800 trees/ha, it will be equal to 100 (20 %), 200 (33 %), 300 (43 %) and 400 trees/ha (50 %), respectively, which can be used for practical recommendations for the renewal felling. At the same time, the main criterion for the intensity of thinning of forest stands is their purpose (protective forests) and their condition (natural regeneration and wind sustainability).

Thinning is the main activity in the system of sustainable forest management. They define target indicators, which will have forest stands by the final cuttings. Scots pine Pinus sylvestris L. is the most widespread of economically valuable species. The aim of the work was an experimental verification of the probability of a species succession in typical pine habitats of the southern taiga of Western Siberia. The experimental area is located in the Timiryazevskiy forestry unit of the Tomsk Oblast, where green-mossy pine forests were cut down in 1999–2001. In 2010, thinning was carried out on young stands on an area of about 45 hectares. The thinning was carried out with a cutting of unwanted trees with strips of 5 m wide, i. e. cutting intensity was 50 %. As a result of studies, it was found that in the control plots, mixed stands with a share of scots pine about 40 % were formed. Aspen predominates in the stand composition, which is almost completely affected by rot of the trunk (90–100 %). Scots pine is much behind growth in aspen (2 times). The radial growth of trunk also indicates the suppression of the Scots pine. The two tier of stands is formed in the strip with thinning, where the upper tier is occupied by Scots pine, and the subordinate is aspen. The important stage in the creation of a new forest generation is the settlement dynamics of the felling area. For Scots pine, the pulsed nature of regeneration is confirmed – over a short period of time (3–4 years). Deciduous trees have a longer reforestation period (6–7 years). The increase in height in the strip with thinning turned out to be significantly higher than in the control plots (40–50 cm versus 20–30 cm). The developed system of felling, which consists in carrying out the first intake of non-commercial thinning at the age of 6–7 years old Scots pine and the second intake of thinning at 10–11 years, ensures the formation of Scots pine young stands.

The main prerequisite for this study is the use of forest resources corresponding to the principles of sustainable forest management. The purpose of this study is to figure out the growth characteristics of pine stands and their physiological response to adverse factors. The experimental material (cores) was selected from pine forests of Ukrainian Polissia using Haglöf increment borer at breast height of 1.3 m. The number of annual rings and the parameters of radial increment were found using the ImageJ software. The result was a tree-ring chronology of sample trees. Statistical analysis of the experimental data proved that the radial increment variability decreases with age, and it ranges within 0.99-2.78 mm. The average radial increment value in the data set under study is 1.79 mm. The average number of annual rings of Scots pine (Pinus sylvestris L.) trees is 80: the minimum is 61, the maximum is 92. The correlation analysis of experimental data proved that the pairwise correlation coefficients of radial increment (-0.54) and current increment by diameter (-0.53) have an inverse relationship with the age of trees, and diameter at breast height with age – a direct relationship (0.87). The developed mathematical models of the dynamics of the width of the annual ring, the diameter at breast height and the current increment by diameter allow estimating the growth characteristics of Scots pine trees throughout their life. The obtained results were compared with the growth tables of fully stocked (at a relative stocking of 1.0) stands. The adequacy test of the developed mathematical models proved the accuracy of the given patterns and is as follows: for the width dynamics of the annual ring – 0.46; the diameter at breast height – 0.78, and the percentage of current increment by diameter – 0.51. Based on standardisation of individual chronologies by calculating sensitivity coefficients, no significant physiological response was established. Accordingly, the impact of short-term stress reactions is insignificant. The maximum resistance of pine stands to adverse environmental factors is achieved at the age of 50-60 years. This study is important to evaluate the impact of climate change and other adverse factors on the growth of pine stands and forecasting the dynamics of biometric indices. The obtained results can be used by the specialists at IA “Ukrderzhlisproekt” to update biometric indices and substantiate the use of forest resources. [ABSTRACT FROM AUTHOR]

A 7-year study was conducted to examine the growth (diameter and root) response of Norway spruce (Picea abies (L.) Karst.) seedlings to elevated CO2 (CO2ELV, 770 μmol (CO2) mol−1) in different mixture types (monospecific (M): a Norway spruce seedling surrounded by six spruce seedlings, group-admixture (G): a spruce seedling surrounded by three spruce and three European beech seedlings, single-admixture (S): a spruce seedling surrounded by six beech seedlings). After seven years of treatments, no significant effect from elevated CO2 was found on the root dry mass (p = 0.90) and radial growth (p = 0.98) of Norway spruce. Neither did we find a significant interaction between [CO2] × mixing treatments (p = 0.56), i.e. there was not a significant effect of CO2 concentrations [CO2] in all the admixture types. On the contrary, spruce responses to admixture treatments were significant under CO2AMB (p = 0.05), which demonstrated that spruce mainly increased its growth (diameter and root) in M and neighbouring with beech was not favourable for spruce seedlings. In particular, spruce growth diminished when growing beside high proportions/numbers of European beech (S). Here, we also evaluated the association between tree-ring formation and climatic variables (precipitation and air temperature) in different admixture types under elevated and ambient CO2 (CO2AMB, 385 μmol (CO2) mol−1). Overall, our result suggests that spruce responses to climate factors can be affected by tree species mixing and CO2 concentrations, i.e. the interaction between climatic variables × admixture types × [CO2] could alter the response of spruce to climatic variables. [ABSTRACT FROM AUTHOR]

The purpose of our study was to assess the individual variability of the response to climatic conditions of the radial increment of Pinus sylvestris L. trees aged 100–140 years. The studied pine stand grows in the conditions of a site with a heterogeneous microrelief in the Voronezh Reserve. The calculated coefficients of synchronicity and correlation of radial increment of a sample of individual Scots pine trees (wood cores). It has been established that in the radial increment of pine trees in the Voronezh Reserve, there is a significant diversity in the reflection of the climatic signal, which, as a rule, manifests itself in certain years that are not extreme in terms of climatic conditions. The reasons for the differentiated reaction of trees to climate are the differentiated conditions of the microrelief, and also, probably, the genetic diversity of forest stands. In natural stands there are individual trees showing very low values of synchronicity coefficients (GLK, %) or correlation coefficients (CC, %) with stand average values. Intrapopulation differences in the response of pine forest stands to fluctuations in climatic factors are one of the forms of protective mechanisms for the survival of a species that have developed as a result of evolutionary development. As our study showed, intrapopulation differences are large in stands of natural origin and not subject to anthropogenic impacts.

The main goals of the study were i) identification of the dwarf pine length and radial increment along an altitude gradient, and ii) analysis of the length and radial increment over time and assessment of the climate impact. In two localities of the orographic unit the Orava Beskydy Mountains (Slovakia), in elevation zones <1450 m, 1450–1600 m and > 1600 m, cross sections of dwarf pine branches were taken and length increments were measured for a more detailed analysis of the growth depending on altitude and climatic conditions. Results do not prove a decrease in the dwarf pine growth in connection with the altitude. Based on different trends of the length and the radial incremental chronologies we assume that the growth of dwarf pine was the result of combination of positive and negative environmental factors (e. g. increase in average temperature, ozone deposition, atmospheric pollution, intraspecific competition) and the species strategy to cope with these factors. An increase in average temperature during the growing season did not appear to be the main factor influencing the growth dynamics of dwarf pine. Nevertheless, the growth of dwarf pine was significantly influenced by temperature of the current and previous growing season and precipitation in April and July. Dwarf pine (Pinus mugo Turra) thickets are a substantial land-cover in European high-elevation mountain ecosystems, where they fulfil important functions in a soil conservation as well as in a wildlife habitat. In many areas across Europe, these thickets have been rapidly expanding over the past decades due to changing environmental conditions. The growth and the spatial spread of dwarf pine became therefore one of the most important issues of nature protection in terms of preserving biodiversity of alpine areas. In the light of these findings the main goals of the study were: i) identification of the dwarf pine length and radial increment along an altitude gradient, and ii) analysis of the length and radial increment over time and assessment of the climate impact. In two different localities, namely Babia hora and Pilsko, of the orographic unit Orava Beskydy Mountains, in altitude zones <1450 m, 1450– 1600 m and > 1600 m (next only zones 1400, 1500, 1600), cross sections of dwarf pine branches were taken, and length increments were measured for a more detailed analysis of the growth depending on the altitude and climatic conditions. By applying dendrochronology we quantified the growth of dwarf pine according to altitude and linked it to species growth responses to climate. We correlated the mean growth chronologies (annual radial increment and annual length increment) with a mean monthly temperature and precipitation for a 17-month window from April of the previous growing season to August of the growing season when the growth occurred, to assess the main climatic factors driving growth. ANOVA showed statistically significant differences in values of the mean annual length and radial increments between individual altitude zones of the investigated localities. The highest increments were observed in the altitude zone 1500 (length increments: Babia hora – 9.2 ± 1.2 cm.year-1, Pilsko – 8.51 ± 0.83 cm.year-1, radial increments: Babia hora – 0.87 ± 0.28 mm.year-1, Pilsko – 0.73 ± 0.19 mm.year-1) with decreasing trends toward to higher or lower altitude (Fig. 2). Results do not confirm a decrease in the dwarf pine growth in connection with altitude probably due to significant impact of other factors, such as habitat conditions or competition within dwarf pine thickets. An average length and radial incremental chronologies were generated for each zone within both examined localities (Fig. 3) and they were tested by the Mann-Kendall test to demonstrate the significance of trends (Tab. 2). The length incremental chronologies showed an increasing trend in zones Babia hora 1400 and 1600 and decreasing trend in zone Pilsko 1400. The radial incremental chronologies showed decreasing trends in zones Babia hora 1600, Pilsko 1400 and Pilsko 1500. The course of some length and radial incremental chronologies did not correlate significantly (Tab. 1). In the case of the zone Babia hora 1600 the course of chronologies even took the opposite trend (Tab. 2). According to the findings, we analyzed the ability of the length and radial growth in more detail to respond to a change of unspecified external conditions. Another interesting finding was that the radial growth responded more sensitively to external factors than the length growth (Fig. 4). The change in the radial increment was more pronounced than the change in length increment with more frequent occurrence of extreme values. Increased average temperatures during the growing season did not appear as the main factor influencing the growth dynamics of dwarf pine, as its positive effect often disappeared in a complex of the other environmental factors. Nevertheless, the length and radial growth of dwarf pine in both localities was significantly influenced by climatic factors; mainly by the average temperature in months of the current and previous growing season and precipitation in April and July, when the radial growth culminated (Fig. 5). Present study does not provide clear evidence of a decrease in the dwarf pine growth in connection with the altitude in the Orava Beskydy Mountains, but it reveals a significant influence of other unspecified factors. Based on different trends of the length and radial incremental chronologies in the zones of individual localities we assume that the growth of dwarf pine is the result of more environmental factors in combination with the species strategy to cope with these factors. Part of this strategy is the unequal intensity of the radial and length growth response and the preference for the length growth over the radial growth, which was reflected mainly in the upper limit of the species’ occurrence. [ABSTRACT FROM AUTHOR]

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Climate change entails shifts in the ranges of woody plants along both latitudinal and altitudinal gradients in the boreal forest biome. In this study, dendrochronological and GIS technologies have been used to evaluate shifts in the upper distribution limits of trees and shrubs in the Eastern Sayan Mountains. The results show that upward expansion along the altitudinal gradient and increase in projective cover against the background of climate warming reach a maximum in shrubs (Betula spp., Salix spp.); then follow Siberian larch (Larix sibirica Ledeb.), Siberian stone pine (Pinus sibirica Du Tour), and Siberian fir (Abies sibirica Ledeb). The abundance of P. sibirica undergrowth in the mountain forest–tundra ecotone has increased, which is due to a rise in May–August air temperatures (r = 0.97). In zones with sufficient moisture supply (high mountains), warming stimulates radial growth of trees and shrubs and promotes their expansion to the mountain forest–tundra. [ABSTRACT FROM AUTHOR]

Climatic changes in the environment are becoming more noticeable each year. Nonetheless, trends in the reaction of radial growth of forest trees to climate change should be studied in different climatic regions due to significant local variability in climatic conditions which are specific for any particular area. We conducted a correlation analysis of the relationship between the parameters of radial increment of black locust (Robinia pseudoacacia L.) and Scots pine (Pinus sylvestris L.) and meteorological factors of the environment in forest areas located in thenorthern steppe zone of Ukraine. We performed surveys in plantations of black locust, growing in hill slope and interfluve areas and also in sandy terrace plots of Scots pine. Over the period of intense vegetatative growth, black locust requires moisture 50% higher than the norm, and Scots pine 43% higher than the norm. It was determined that maximum increment for the studied plants occurred under the influence of a combination of factors involving reduction of the air temperature by 2.6–2.7 °С below the norm for black locust and by 2.3–2.5 °С for Scots pine. During the period of lower vegetative activity, Scots pine demonstrated lower sensitivity compared to black locust. This paper provides a statistical characteristic of the radial increment of trees in the conditions of changes in meteorological factors which limit their growth. The article provides data on multiple correlation of radial increment of the tree stands in relation to growth locations; demonstrates correlation dependency of radial increment of the studied trees on the precipitation and mean monthly temperatures over different time periods and during particular months. Radial increment of Scots pine exhibited most positive correlation with the total of precipitations throughout the period. For the stands of black locust, correlation coefficients were higher and distinguished by both positive and negative values. In the current increment of this species, a negative correlation relation was observed with the total precipitation in July, August and September, and positive correlation with the remaining months of the year. By contrast, radial increment of black locust and Scots pine positively correlated with air temperature during all time periods and particular months.

It has been investigated that since the beginning of the 19th century, the degradation of pine stands has acquired a huge scale on all continents. In Ukraine, according to the Ministry of Ecology and Natural Resources of Ukraine, the average annual temperature since the beginning of the 20th century has increased by more than 2 degrees Celsius, including 1.2 degrees over the past 30 years. In recent years, the number of days with maximum summer temperatures above 35-40 degrees has almost doubled, which refers to extreme weather events. In most of the territory of Ukraine, there is already a tendency towards an increase in drought, an increase in fire hazard, the recurrence of years during which forest plantations will sustain water stress, damage by pests, as well as degradation of forest ecosystems as a result of an increase in duration of hot periods. It has been determined that dendrochronological methods are used to study the relationship between climate change and radial growth of pine. The main methods for studying radial growth is taking cores at a height of 1.3 meters from two opposite radii to prevent random factors from affecting the radial growth. The width of the annual rings is determined using devices for dendrochronological studies with automatic data recording. The data on the values of annual rings are processed according to the programs of the International Tree-Ring Data Bank (ITRDB). To synchronize the series with the establishment of the calendar year, the formation of each annual increment, the specialized COFECHA program is used. It has been established that the growth of scots pine is limited by climate humidification and the presence of a sufficient amount of moisture in the soil; however, in the presence of extreme temperatures, a negative trend towards drying out of forest plantations still persists. [ABSTRACT FROM AUTHOR]

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is a non-native tree species in Slovenia with the potential to partially replace Norway spruce in our native forests. Compared to spruce, it has several advantages in terms of volume growth, wood quality and tolerance to drought. This is important given the changing climate in which spruce is confronted with serious problems caused by increasing temperatures and drought stress. At three sites (one on non-carbonate bedrock and deep soils, and two on limestone with soil layers of varying depths), 20 Douglas-fir and 20 spruce per site were sampled in order to compare their radial growth response to climate and drought events. The radial growth of Douglas-fir exceeds that of spruce by about 20% on comparable sites. It is more responsive to climate than spruce. Above-average temperatures in February and March have a significant positive effect on the radial growth of Douglas-fir. In recent decades, above-average summer precipitation has also had a positive influence on the radial growth of Douglas-fir. Compared to spruce, Douglas-fir is less sensitive to extreme drought events. Our results indicate that Douglas-fir may be a good substitute for spruce in semi-natural managed forest stands in Slovenia. The planting of Douglas-fir should be allowed in Slovenian forests, but the proportion of it in forest stands should be kept lower than is the case with spruce today.

The article considers the Voronezh region climate dynamics over a 30-year period in comparison with the previous climate normal. Mathematical analysis of the relationships of cyclic changes in radial increment of native tree species of the south of the Russian Plain - Scots pine (Pinus sylvestris Linnaeus) and English oak (Quercus robur Linnaeus) ‒ with climate factors (air temperature, amount of precipitation) is done. The greatest importance of April and, especially, May sums of precipitation for the formation of radial increment of native species (P. sylvestris and Q. robur) was confirmed. The forecast of changes in stand growth and productivity of the studied species is presented.

Comparative observations of the growth dynamics of various trees planted in the arid conditions of Volga-Ural interfluve were conducted taking into account the current change in natural and climatic conditions. The conditions and causes of sudden changes in the growth rates of trees were analyzed. The growth rates of adult species of the oak and the Pennsylvanian ash cultivated on clay soils and those of the Scots pine cultivated on sandy soils were studied. The previously revealed correlation between the width of the annual tree ring and the hydrothermal conditions of the vegetation period were used, with allowance for different functional significance of spring water recharge (precipitation in the cold season), the precipitation during the vegetation period, and the groundwater level in its annual formation, as well as the limiting effect of the air temperature in the spring and summer on the increment. The possibility of a sudden change in the oak growth dynamics caused by strong long-term soil and atmospheric drought during an extremely dry year (1972) is shown, when the trees of all ranks had a significantly suppressed growth not only this year but also the next 6–7 years. This may happen due, for example, to a malfunction of the cambium or the death of a large number of lateral and absorbing roots. A significant change in the growth rates of trees during long-term annual climatogenic lowering or raising of the level of fresh groundwater is shown, when the lower boundary of the root systems separates from the capillary border or is saturated with moisture from it, significantly changing the moisture provision of plants. The results obtained can explain the causes of the sudden change in tree growth in the studies of tree rings. [ABSTRACT FROM AUTHOR]

This paper explores the effects of three types of admixture treatments: (1) monospecific (M: European beech surrounded by six European beech seedlings), (2) single-admixture (S: European beech surrounded by six Norway spruce seedlings), and (3) group-admixture (G: European beech surrounded by three Norway spruce and three European beech seedlings), and two different CO2 concentrations ([CO2]): ambient [AMBCO2, 385 μmol (CO2) mol−1] and elevated [ELECO2, 770 μmol (CO2) mol−1] on the stem diameter increment (DI), based on a 7-year monitoring of the diameter growth of European beech (Fagus sylvatica L.) seedlings. Furthermore, to improve our understanding of the influence of climatic variables, we assessed the effects of precipitation and temperature on radial growth. After 7 years' experience (irrespective of admixture treatment), our data were not able to confirm the effect of elevated CO2 on the diameter growth (p value = 0.35), but the result was changed when the effect of elevated CO2 was considered under the different types of admixture. Elevated CO2 along with single-admixture increased the diameter increment significantly (p value = 0.001). In contrast, we characterized a significant effect of AMBCO2 × G interaction on DI (p value = 0.002). But DI was unaffected by elevated CO2 in M (p value = 0.77). In both [CO2], inter-specific competition with spruce resulted in the highest radial growth. The inter-specific interaction was most pronounced in the lower proportion with spruce (S) in ELECO2, while in ambient CO2, the higher proportion with spruce (G) had the greatest effect on the radial growth. With respect to the climatic factors, our observations showed that temperature had a stronger influence than precipitation in ELECO2, but in AMBCO2, precipitation had the strongest effect on the radial growth as indicated by the statistically significant correlation between climatic variables and radial growth. Overall, our result suggested that seedlings growth was more under the control of climate and edaphic factors than dependent on tree species diversity and CO2 concentrations. [ABSTRACT FROM AUTHOR]

Pruning requires significant investment, therefore, the aim of the study was to characterize occlusion of branch wounds and changes in radial increment as well as frequency of browsing damages after pruning of Norway spruce (Picea abies (L.) Karst.) in order to provide data for financial calculations and recommendations for practical forestry. Altogether 1,614 pruned and 4,368 unpruned trees from 45 Norway spruce stands were measured and cored. Degree of wound occlusion and browsing damages were assessed, and additional volume increment estimated in each stand. Pruning resulted in significant increase of length of branch-free section: for unpruned trees it was 0.3 ± 0.07 m, but for pruned 3.4 ± 0.10 m. Branch wounds for most of the trees (68%) were filled with resin (occluded), for lower share of trees (31%) – still open, but for some trees (1%) completely occluded. Branch wound occlusion rate was not affected by differences in stand density, but was significantly affected by stand age: proportion of trees with occluded branch scars increased with age. Trees with occluded branch wounds had a significantly higher increase in tree ring width after the pruning in comparison to the period before pruning than trees with open branch wounds, emphasizing the importance of radial increment in development of branch-free layer of wood. Pruning resulted in minor (−7% or −0.28 ± 0.05 m3 ha−1) reduction of annual increment that was statistically significant only up to 3 years after this forest management activity for stands younger than 17 years and with mean height up to 10.5 m. Pruned trees were significantly more browsed than unpruned (6.1% and 2.7%, respectively).

Key message: Continuously suppressed S.torminalis trees were found to be highly sensitive to release cuttings. After release diameter growth increased drastically, the crown redensified from the inside and seeds were produced during the first growing season. Sorbustorminalis is valued for its timber characteristics and ecological role in cultural landscapes. Due to its increased drought tolerance, the species is of growing interest in the context of silviculturally driven climate change adaptation measures. Due to its comparably slow growth, it often forms a second canopy layer below other deciduous tree species. With regard to its ecological and economic value, forest practitioners need to know whether releasing these continuously suppressed individuals from competition is worth it. Therefore, the objective of this study was to examine the effect of release cuttings on the crown growth and radial increment of S.torminalis heavily suppressed by surrounding sessile oaks (Quercuspetraea). We observed changes of shoot and diameter growth within the first year following release cuttings. The overall average annual shoot growth more than tripled when compared to pre-release growth patterns (from 1.9 to 6.2 cm). The greatest release effects were found in the inner part of the crown. The majority of the shoots forming the crown periphery developed fruits and showed only restrained increment. Crown redensification from inside was accompanied by the development of epicormic branches in previously branch-free bole sections. Following release cuttings, diameter growth increased by several orders of magnitude. Altogether, release cuttings seem to have a very positive effect on the vitality of continuously suppressed S.torminalis trees. All released trees grew vigorously and developed fruits throughout the crown surface. Thus, release cuttings may facilitate species propagation and reduce inbreeding effects. [ABSTRACT FROM AUTHOR]

The time series of the radial increment of pine Pinus sylvestris L. in 1945–2015 were studied on the territory of the Krasnoturansky pine forest in the stands damaged during the outbreak of the pine looper Bupalus piniarius L. in 1974–1978 and in the stands not damaged by the pest. To assess the differences in the processes of radial increment of trees in damaged and undamaged stands before the outbreak, it is proposed to use the regulatory characteristics of time series, such as the values ​​of n delay (autocorrelation) and the amplitude s of fluctuations in time series. According to these indicators, one can numerically assess the inertia of the processes of regulation of radial increment. Since the regulatory characteristics can only be correctly calculated for stationary time series, the series of the first differences of the radial increment were used for the calculations. The trees in the stands that were attacked by insects were characterized either by the absence of delay in the time series, or by sufficiently large values ​​of the order of autocorrelation (n). Moreover, fluctuations in the current radial increment relative to the age trend were significantly greater in trees in damaged stands than in undamaged ones. The rate of growth recovery in trees damaged by insects depending on the regulatory characteristics of the time series of radial increment before the onset of damage was assessed. The obtained characteristics can be used to assess the risk of phyllophages' attacks on stands and the rate of restoration of stands damaged by insects. [ABSTRACT FROM AUTHOR]

This paper addresses the effects of climatic limiting factors (precipitation and air temperature) on the radial increment variability of Scots pine (Pinus silvestris L.) growing in the Voronezh State Biosphere Reserve under the conservation regime conditions. A natural 200-year-old pine stand belonging to the grassy pine forest with oak type was studied. The following analyses have been performed: a mathematical analysis of the strength and frequency of the relationship between the monthly precipitation amounts and average monthly air temperatures (based on the data of Voronezh and Voronezh Nature Reserve meteorological stations), as well as radial increments of the Scots pine throughout the period of 80 years. It was established that the sums of precipitation in April and especially in May have the maximum effect on the radial increment of Scots pine (spring wood). The precipitation in July–August significantly affects the late wood growth. A strong correlation between the radial increment and September and especially October temperatures of the current year (r = 0.43) and the previous year (r = 0.40) was identified. In addition, a negative correlation between the radial increment and summer temperatures was established. The correlation ratio of the relationship between the meteorological factors and radial increment was considerably higher than the correlation index, which confirms the nonlinear nature of this relationship. Based on the cyclical dynamics of the radial increment of Scots pine (11- and 34-year cycles), models have been built using two forecasting methods (Caterpillar Singular Spectrum Analysis (SSA) and an additive increment model described by a sinusoid function with a given period), and an increment forecast for the 10-year period was produced. According to the models, the radial increment is going to decrease in 2018–2019, increase in 2021 ± 1, and decrease again in 2024 ± 2. [ABSTRACT FROM AUTHOR]

The cambial activity and radial growth of three tropical species, Tetrameles nudiflora, Hopea pierrei and Cleidion spiciflorum at Chang Island were measured monthly from December 2011 to May 2012 and bi-monthly from June to November 2012. We installed electronic dendrometers to analyse stem diameter variation. Cambial activity was quantified by counting the layers of undifferentiated cells in the cambial zone at 10 randomly chosen positions. The relationships between the cambial activity and climatic factors, i.e. rainfall, temperature, relative humidity and soil moisture were investigated by Pearson's correlation. The number of cambial layers was significantly correlated with relative humidity. Growth dynamics of the three species differed considerably. The cambium of T. nudiflora appeared active year-long and was most active at the end of August. Cambial activity for H. pierrei and C. spiciflorum was highest at the end of June and July respectively, but was not significantly correlated with climate. Radial growth measurements showed that all three species contracted in the afternoon from 2.30--6.00 p.m., and the maximum enlargement occurred before 9 a.m. In this rainforest with high rainfall trees grow year-round, and radial growth rate depended on the water cycle rather than the weather conditions in the area. [ABSTRACT FROM AUTHOR]

This investigation examined the effects of two different carbon dioxide concentrations ([CO2]): Ambient (A, 385 μmol (CO2) mol−1) and elevated (E, A+385 μmol (CO2) mol−1)) on the tree-ring width and early to latewood proportion in Norway spruce for seven years (2006-2012). Further, to improve our understanding of the influence of climatic variables, we assessed the effects of precipitation and temperature. Our observations showed that spruce trees growing under elevated CO2 (EC) formed less early (p > 0.05) and latewood (p < 0.05) and hence smaller annual increments (p > 0.05) than trees in ambient CO2 (AC). Early to latewood proportion was nearly 73% and 75% in AC and EC, respectively. In both CO2 concentrations, the largest tree-rings and earlywood width was observed during 2009 and 2010, which is coincident with the highest precipitation in May (2010) and the highest air temperature in April (2009). Moreover, to determine the association between the latewood formation and air temperature during the second half of the growing season, and correlation between the earlywood formation and precipitation during the first half of the growing season we run Spearman’s correlation test, the determination coefficient values for latewood formation were r = 0.45 (AC) and r = 0.68 (EC), and for earlywood formation were r = 0.53 (AC) and r = 0.42 (EC), although coefficient values were not statistically significant (p > 0.05). Also, our study indicated that temperature had stonger influence than precipitation in EC, but in AC precipitation had the strongest effect on radial growth.

Studies of spatial-temporal variability of the upper boundary of the forest on the north-western coast of Lake Baikal (Baikal and Upper Angara Ridges) are performed on the base of the analysis of forests renewal processes and of the dynamics of larch radial increment in the ecotone of the forest upper boundary and out of it. The presence of a large amount of well-developed uplands and circuses with considerable heights drops in the structure of mountain system favours formation of interrupted boundary between forest and subgoltsy belt. The timber stand of the upper forest boundary in the studied area is represented by Daurian larch. Three tree-ring chronologies of larch are obtained. The longest chronology is obtained for mountain taiga belt of Baikal Ridge and is as long as 460 years. Since 1980ies, a sustainable trend of increase of radial trees growth is observed. It is observed the most distinctly in trees of the upper forest boundary on the Baikal Ridge. There is advancing of trees species into subgoltsy belt and into mountain tundra, which depends, respectively, on slopes heights, exposition and tilting, on sites of growth of concrete cenoses. Modern peculiarity of the vegetation of the studied area is presence of abundant viable larch undergrowth (from 2–3 to 25 y.o.) and fir in the ecotone of upper forest boundary and in subgoltsy belt, as well as appearing of single specimens of spruce. Main undergrowth mass (2/3) is presented by trees aged in average 15–25 y.o., i.e., they appeared in late 1980ies. Due to increase of snow cover thickness in winter, the trees young growth obtained great protection from freezing resulting in the increase of ability of young growth to live up to elder age.

At the upper forest belt in the primary Siberian stone pine–Siberian larch forests in the headwater Aktru, Severo-Chuisky Range, the Altai Mountains, Russia the qualitative analysis of tree and branch radial increment was made in the main growth form (upright–trunk tree) of Siberian stone pine (Pinus sibirica Du Tour), its relatively autonomic structures (power candelabra branches and elfin wood form), and the transitional morphological (“living” stumps, “living” windfallen trees, shrub-like form, and trees with multi-storey root system) and other growth (clump-like trees) forms. The external (weather and climatic processes, geomorphological events, and phytocoenotic interactions) and the internal factors effect on initiation and existence of the morphological structures and the transitional morphological forms and their growth. The internal factors are 1) absolute and biological age of the trees, 2) primary or secondary origin of the branches, 3) degree of development of the roots, and 4) the connection between the morphological structures and the mother trunk and root. Under favourable growth conditions in the Siberian stone pine trees the form of the curve of the trunk increment is close to the bell with maximum increment in the earlier age when growth temp and acceleration are maximum in the sites. The forms of growth curves can be approximate the equations of the parabola or the exponential curves with the positive or negative accelerations as well as the horizon straight line when the growth curves become plane

The paper presents the results of silvicultural research of phytocenosis components and dendrochronologocal and dendroclimatic analyses of radial growth of pine and limiting factors in 50-70 year old stands of Scots pine in different stages of recreational digression, which grow in a suburban area of Voronezh. Weighted average of the category of the state of the examined tree stands increases from I, 7 to III, 1 with increasing the stage of digression from I to IV. On III-IV and IV stages of digression tree stands are classified as “very weak.” With increasing recreational load the projective ground cover of herbaceous plants and their aboveground phytomass decreases, the share of participation and diversity varies (weeds and meadow grass appear). The tree stands which exposed to intensive recreational impact significantly more affected by drought in 2010. In 2012 – 2013 years the average radial growth of trees increased in stands which are in I and II stages of digression, while in stands belong to III and IV stages it continues to decline. So far, the desiccation of particular trees continues in all artificial pine stands regardless of the stage of digression. The coefficients of variation of growth sharply increase to a maximum value (> 60 %) in the years after the severe drought, and after two-year especially severe drought (1971-1972 and 2009-2010) the increase of the coefficient of variation is also observed during two or even three years (1973–1974 and 2011-2013). It is clear that Stage IV of the digression is a transition of the tree stand to irreversible phase of deterioration

This paper is devoted to revealing the distinctive characteristics of radial growth of larch trees (Larix gmelinii (Rupr.) Rupr.) growing in permafrost contrast conditions of the north and south facing slopes (Central Siberia, 64°19´23˝ N, 100°13´28˝ E). Even-aged larch stems regenerated after strong fire in 1899 in opposite north and south facing slopes of the hills situated on the banks of Kulingdakan stream were under study. Two sample sites at the middle part of the slopes were established. 23 model trees in the north facing slope and 13 ones in the south-facing slope were selected for dendrochronological analysis. From each tree, disks at 1.3 m height of the stems were taken. Tree ring widths were measured, comparative analysis of dynamics of radial growth in the slopes was made. In order to separate time intervals, characterized by distinctive climate impact on radial increment, sliding response functions were calculated and analyzed. Daily solar radiation for both sample sites was calculated. The results showed that solar radiation in the north-facing slope is 20 % less than that in south-facing slope. Solar radiation regime promotes intensive thickening of moss-lichen cover, so that its thickness to 2009 was nearly two times thicker than in south-facing slope. Both factors affected the worth thermal soil growth conditions in the north facing slope. The latter was responsible for narrower ring widths formation in the stems and governed higher sensitivity of the trees to air temperature in the periods of cambium reactivation, start and intensive growth.

Defoliation caused annually by Cameraria ohridella has a considerable impact on the general condition of horse chestnut trees. We investigated the consequences of tree endotherapy against this insect. Wood samples, leaves and insect specimens were collected ten years after the treatment (injection) with pesticides. Insect invasion was manifested in all investigated trees by distinct radial growth depression. Treatment resulted in a growth upturn, while non-treated trees maintained decreased growth. The overall foliage infestation level was lower in treated trees, but pupal mass and potential fecundity of insect females were not affected. Our study revealed a long-lasting, positive effect of endotherapy on trees' appearance and growth. [ABSTRACT FROM AUTHOR]

We have studied the features of annual ring development in stands of Bryansk oblast polluted by radionuclides from the Chernobyl accident. The evidence of relationships between average annual radial increment and the average width of spring and summer layers of timber within an annual ring and stand density is observed in 80-year-old blueberry pine forests. We find direct links between annual increment and its spring and summer components with average distance between trees. The stand density has the most pronounced effect on the spring growth of timber, with an increment gradient from 0.204 to 0.244 mm m-1. In summer it varies from 0.038 to 0.066 mm m-1. The contribution of the late timber in a tree ring increases from 50.4-54.8% in the least dense to 72.5-75.8% in the densest stands. However, chronic irradiation does not differ across the stand density gradient. The stimulation of the annual growth increment by irradiance is estimated from 50.4 to 51.9%. It contributes from 39.1 to 46.1% of the spring increment to 43.2-58.6% of the summer increment with 95% confidence. [ABSTRACT FROM AUTHOR]

The article considers the Voronezh region climate dynamics over a 30-year period in comparison with the previous climate normal. Mathematical analysis of the relationships of cyclic changes in radial increment of native tree species of the south of the Russian Plain - Scots pine (Pinus sylvestris Linnaeus) and English oak (Quercus robur Linnaeus) - with climate factors (air temperature, amount of precipitation) is done. The greatest importance of April and, especially, May sums of precipitation for the formation of radial increment of native species (P. sylvestris and Q. robur) was confirmed. The forecast of changes in stand growth and productivity of the studied species is presented. [ABSTRACT FROM AUTHOR]

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The harvesting of Copaifera oleoresin is an important source of income for traditional Amazonian peoples and natural product industries. However, many production processes-related aspects still require more concrete information if they are to be incorporated in effective forest management systems. The objective of this study was to evaluate the yield of Copaifera multijuga Hayne oleoresin harvesting over time, including those factors (diameter, heartwood percentage, harvesting season and age) that may influence its production and be linked to forest management practices. Research was carried out in a natural forest area in Adolph Ducke Forest Reserve, Manaus, Amazonas, Brazil (2°57′43″S and 59°55′38″W). The sixty C. multijuga trees selected included productive and non-productive individuals (with 7 and 32 years of fallow). Oleoresin production was monitored for a period of two years, and the following variables measured: trunk DBH, heartwood percentage, tree age, fallow interval and climatic seasonality. To analyze growth rings (demarcation, counting and width measurement), wood samples were collected from the trunk of productive and nonproductive trees. Tree ages were determined with growth ring counts. Tree ring widths were used to calculate radial growth. Accumulated radial increments were determined and growth curves constructed. Oleoresin production showed a stronger relationship with tree diameter and percentage of heartwood than with age. This shows that age is not the determining factor in the production, but rather the diameter and the percentage of heartwood. However, the greater amounts of oleoresin was harvesting in older trees. Trees initially not productive (1978) became productive 32 years later (2012). Radial trunk growth and consequent heartwood incorporation may have contributed to this. This explains why trees with small diameters do not produce oleoresin, since they have sapwood, but lack heartwood. On the other hand, some trees, whose production has declined, were beginning to show growth curve stabilization and likely the onset of senescence. The results also indicated that production is influenced directly by number of years between harvests. The best time to harvest oleoresin is at the end of the rainy season. Although oleoresin production declines naturally over the years, good management practices can be adopted to produce a lasting production system, maximizing the productive life of the trees, and linking economic and ecological viability. Key is the use of a minimum tree trunk diameter (DBH ≥ 45 cm) during initial oleoresin harvesting, and a resting period sufficient to allow adequate oleoresin synthesis by managed trees. [ABSTRACT FROM AUTHOR]

Global change affects the functioning of forest ecosystems and the services they provide, but little is known about the interactive effects of co-occurring global change drivers on important functions such as tree growth and vitality. In the present study we quantified the interactive (i.e. synergistic or antagonistic) effects of atmospheric nitrogen (N) deposition and climatic variables (temperature, precipitation) on tree growth (in terms of tree-ring width, TRW), taking forest ecosystems with European beech ( Fagus sylvatica L.) as an example. We hypothesised that (i) N deposition and climatic variables can evoke non-additive responses of the radial increment of beech trees, and (ii) N loads have the potential to strengthen the trees' sensitivity to climate change. In young stands, we found a synergistic positive effect of N deposition and annual mean temperature on TRW, possibly linked to the alleviation of an N shortage in young stands. In mature stands, however, high N deposition significantly increased the trees’ sensitivity to increasing annual mean temperatures (antagonistic effect on TRW), possibly due to increased fine root dieback, decreasing mycorrhizal colonization or shifts in biomass allocation patterns (aboveground vs. belowground). Accordingly, N deposition and climatic variables caused both synergistic and antagonistic effects on the radial increment of beech trees, depending on tree age and stand characteristics. Hence, the nature of interactions could mediate the long-term effects of global change drivers (including N deposition) on forest carbon sequestration. In conclusion, our findings illustrate that interaction processes between climatic variables and N deposition are complex and have the potential to impair growth and performance of European beech. This in turn emphasises the importance of multiple-factor studies to foster an integrated understanding and models aiming at improved projections of tree growth responses to co-occurring drivers of global change. [ABSTRACT FROM AUTHOR]

This paper defines pointer years and years with distinctive tree rings in the growth of beech in 3 sites (ecological units-EU) of the area of Đerdap, in order to observe the reactions of trees to the effects of various factors of growth. The pointer years were determined by the Schweingruber (1983) methodology. The years with distintive tree rings were defined as the years of beech growth with very pronounced distinctive growth rings (annual ring width at least ± 2 standard deviations higher or lower than the arithmetic mean) and pronounced typical growth rings (annual ring width at least ± 1.5 standard deviation higher or lower than the arithmetic mean). The common pointer years for the growth of beech in the site conditions of all three ecological units are 1977 and 1988 (negative pointer years). A particular pointer year is 1988, when in more than 90% of trees under the analyzed environmental conditions the marked reduction of tree rings width of the trees (EUB) or very pronounced reduction in the width of tree rings (EUA and ESV) were observed. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Istraživanje klimatskih promena na životnu sredinu: praćenje uticaja, adaptacija i ublažavanje]

This paper presents the first regional research of the chronologies of sessile oak trees and definition of the local (master) chronology of sessile oak in the area of Fruška Gora. In addition, the aim of this study is to determine the strength of the common signal in the growth of sessile oak and its dendroclimatological potential under the given conditions. The quality of the local series of radial increment (chronology) and the strength of the common and climatic signals were evaluated using the following parameters: average mean sensitivity, expressed population signal, signal-to-noise ratio and the variance explained by eigenvectors in the procedure of analysis of the principal components. The results have shown that the obtained master chronologies are of satisfactory quality and reliability, and that they contain a sufficient general common ”signal”, which is a characteristic of all analyzed trees that can be processed in all dendroclimatological analyses. It was concluded that, under the investigated site conditions, sessile oak showed low to medium sensitivity of reaction to the modifications of environmental conditions in the past 90 years. [Projekat Ministarstva nauke Republike Srbije: Šumski zasadi u funkciji povećanja pošumljenosti Srbije]

The radial increment of Scots pine growing in the forest-steppe zone of Western Transbaikalia at five sites is studied. For each site, additional samples are collected, which allows us to increase reliability and build two regional chronologies. An analysis of chronology correlations with monthly temperatures, precipitation, and Selyaninov hydrothermal coefficient is carried out. The analysis of 10-day moving climatic series makes it possible to clarify the periods of climate impact on the increment: the main limitation of pine increment in the region is observed by moisture supply, including conditions during previous (from late July to late September) and current (May to mid-July) vegetative seasons. Fluctuations of 23-35 years in the dynamics of climatic factors and radial increment of the pine are found. [ABSTRACT FROM AUTHOR]

Pruning requires significant investment, therefore, the aim of the study was to characterize occlusion of branch wounds and changes in radial increment as well as frequency of browsing damages after pruning of Norway spruce (Picea abies (L.) Karst.) in order to provide data for financial calculations and recommendations for practical forestry. Altogether 1,614 pruned and 4,368 unpruned trees from 45 Norway spruce stands were measured and cored. Degree of wound occlusion and browsing damages were assessed, and additional volume increment estimated in each stand. Pruning resulted in significant increase of length of branch-free section: for unpruned trees it was 0.3 ± 0.07 m, but for pruned 3.4 ± 0.10 m. Branch wounds for most of the trees (68%) were filled with resin (occluded), for lower share of trees (31%) - still open, but for some trees (1%) completely occluded. Branch wound occlusion rate was not affected by differences in stand density, but was significantly affected by stand age: proportion of trees with occluded branch scars increased with age. Trees with occluded branch wounds had a significantly higher increase in tree ring width after the pruning in comparison to the period before pruning than trees with open branch wounds, emphasizing the importance of radial increment in development of branch-free layer of wood. Pruning resulted in minor (-7% or -0.28 ± 0.05 m³ ha-1) reduction of annual increment that was statistically significant only up to 3 years after this forest management activity for stands younger than 17 years and with mean height up to 10.5 m. Pruned trees were significantly more browsed than unpruned (6.1% and 2.7%, respectively). [ABSTRACT FROM AUTHOR]

This study aims to develop a screening approach for genetic tolerance to industrial pollution in Scots pine. The relationship between temporal variation in strength of genetic control on radial increment of seed orchard clones affected by air pollution and past pollutant emissions from a nitrogen fertilizer plant in central Lithuania was assessed. The annual radial increment was measured from increment cores. High present-day defoliation was associated to low radial increment during intensive pollution period in the years 1992 - 1995 when high defoliation was recorded in the stands. There was a tendency for a stronger genetic control of radial increment during the years of high defoliation. The clones representing the extremes of high and low radial increments during the stress period of 1992 - 1995 were selected for further tolerance testing based on needle anatomy traits.