Search Results (25)

European beech (Fagus sylvatica L.) and Oriental beech (Fagus orientalis Lipsky) are ecologically and economically important tree species in European and western Asian forests, which are currently significantly affected by global climate change. To assess their response to climate variability, tree-ring data from 12 permanent research plots (PRPs) were analyzed in Central Europe and Turkey, covering an elevational gradient from 360 to 1430 m above sea level (a.s.l.). Using 360 tree cores, the relation between air temperature, precipitation, and climate-related stress on radial growth was investigated, alongside production potential and carbon sequestration. The results show that European beech is more sensitive to both air temperature and precipitation than Oriental beech. Carbon sequestration of forest stands ranged from 37 to 361 t·ha⁻¹ depending on the elevational gradient, with European beech storing, on average, 33.1% more carbon than Oriental beech stands. Radial growth was related to both air temperature and precipitation, with the strongest effects observed at mid-elevations (740–950 m a.s.l.). In European beech, both current and previous year temperatures significantly related to growth, whereas in Oriental beech, only the current year was critical. July was the most influential month for tree growth in both species. On PRPs located at lower elevations, radial growth over the past 20 years decreased by 13.1%–19.3% compared to the previous 20-year period, whereas in mountainous areas, it increased by 5.6%–9.8%. Low precipitation during the growing season was the main limiting factor for growth in lowland areas, whereas low temperatures were the primary constraint in mountainous regions, and vice versa. In recent years, the frequency of negative pointer years with extremely low radial growth has been increasing, reflecting a rising occurrence of climate extremes. These findings highlight species-specific climate sensitivities, emphasizing the importance of adaptive forest management strategies for mitigating global climate change impacts and increasing carbon sequestration. Full article

In recent decades, there has been an increase in European wild ungulate populations, often associated with a decline in health and spread of disease. This is true for the roe deer (Capreolus capreolus), the most common European cervid, with populations apparently affected by fibropapillomatosis, an increasingly common cancer. To date, however, there has been little research into this disease, thus many interactions remain unclear and descriptions of tumour composition are poorly validated. The main aim of the present study was to evaluate the presence and concentration of toxic heavy metals in roe deer skin tumours. Our results confirmed the presence of virtually all the metals tested for, i.e., Pb, Hg, Cd, As, Cr, Mn, Al, Co, Cu, Ni, Se, Zn, and Fe, with the highest average concentrations found for Cr (0.99 mg/kg⁻¹ ± 2.23 SD), Cd (0.03 mg/kg⁻¹ ± 0.03 SD), and Hg (0.02 mg/kg⁻¹ ± 0.02 SD), exceeding FAO limits for meat from slaughtered animals. We also observed a significant positive relationship between heavy metal concentration and age, especially for Pb, As, Hg, Mn, Se, Al, Zn, and Ni. Our findings provide a strong baseline for further research on the impact of fibropapillomatosis, not only on the welfare and health status of game but also on the final consumer of venison, which in many respects is regarded as a high-quality, ecological, and renewable wild resource. While deer with this disease are not considered qualitatively or medically defective, they could represent a potential reservoir of substances toxic to humans and could affect substance levels in adjacent tissues or the animal as a whole. Full article

Oak is one of the most economically important hardwood tree species in Europe, and its prevalence will increase due to progressing global climate change, according to predictive models. With the increasing demand for timber and with the need for a balance between carbon emissions and sequestration, it is essential to address the afforestation of agricultural land. Therefore, this research aimed to investigate the physico-mechanical properties and anatomical structure of pendulate oak (Quercus robur L.) wood—specifically focusing on the trunk’s cross-section—in post-agricultural areas compared with the forest land in the western part of Poland. Wood density, bending strength, modulus of elasticity, and other parameters were analyzed from 1626 wood samples. The analysis of physico-mechanical properties reveals that, historically, agricultural land use has an almost negligible impact on wood quality. Despite significant differences in small vessel diameter and fiber length favoring trees from post-agricultural land, the physico-mechanical properties remain consistent. Large vessel measurements show comparable diameter and length in both land types. These findings suggest that post-agricultural land can serve as an effective alternative for high-quality pendulate oak wood production for industrial purposes. However, wood from post-agricultural land may exhibit a decrease in modulus of rupture by over 30% and potentially lower density above the trunk’s halfway point. This observation hints at the fact that oak trees in post-agricultural areas could be cultivated in shorter rotation periods compared to forest land. Full article

Scots pine (Pinus sylvestris L.) represents one of the most important commercial coniferous tree species, providing valuable timber. Due to climate change, it is experiencing serious problems in some areas, therefore, finding a suitable substitute for its wood is currently a challenge. In this study, we compared the wood quality of three different non-native pine species and Scots pine growing at the same site to ensure identical growing conditions. Black pine (Pinus nigra J. F. Arnold), a pine species native to Southern Europe, lodgepole pine (Pinus contorta Douglas ex Loudon), and ponderosa pine (Pinus ponderosa Douglas ex C. Lawson) native to North America were compared to Scots pine for selected quantitative (productivity) and qualitative (physical and mechanical) properties. Significant differences between pine species were found in all quantitative dendrometric parameters, except average diameter at breast height. The stand volume ranged from 157 m³ ha⁻¹ for lodgepole pine to 356 m³ ha⁻¹ for Scots pine. For qualitative characteristics, wood density, shrinkage, and compressive strength were used to find differences among species in choosing the best alternative. The highest wood density was obtained for Scots pine (458 kg m⁻³), followed by black pine with 441 kg m⁻³. The density of the remaining pine species was significantly lower. Scots pine also exceeded the tested species in compressive strength (44.2 MPa). Lodgepole pine achieved the second highest value (39.3 MPa) but was statistically similar to black pine (36.5 MPa). The tested pine species exhibited similar values in shrinkage, which were statistically insignificant, ranging from 14.3% for lodgepole pine to 15.1% for Scots pine. Based on applications and preferred characteristics, black pine or lodgepole pine could serve as the Scots pine substitute in some areas. And vice versa, ponderosa pine did not attain the Scots pine wood quality. Full article

The silver fir (Abies alba Mill.) is among the most valuable conifers in Europe for ecological and economic reasons. Throughout the course of history, primarily in the 20th century, its share in stands has been declining due to ill-suited management practices, especially clear-cut management, air pollution (SO₂ and NO_X emissions), and wildlife-induced damage. This literature review compiles findings from 338 scientific papers. It describes futures for silver fir and its distribution, ecological requirements, threats and diseases, seed production and nurseries, and forest management practices with emphasis on ongoing climate change. Based on recent knowledge of fir ecology and population dynamics, small-scale shelterwood and selection management have been introduced in fir stands, which have also stabilized them. Fir is an essential species for maintaining high stability and biodiversity, especially on planosols and in waterlogged habitats. Owing to its shade tolerance and environmental plasticity, it can coexist very well with many tree species in mixtures, which can increase the productive potential of stands within the natural range in Europe. The average stand volume of mature fir stands ranges from 237–657 m³ ha⁻¹. For its successful natural regeneration, it is essential to reduce cloven-hoofed game and thus prevent bud browsing damage. The attractiveness of fir in terms of heavy browsing is the highest of all conifers (52% damage). On the other hand, fir is a species relatively resistant to bark stripping and the spread of secondary rot compared with Norway spruce (Picea abies [L.] Karst.). Under global climate change, fir is expected to shift to higher elevations with sufficient precipitation, while in the southern part of its natural range or at lower elevations, outside water-influenced habitats, it is likely to decline. Climate change is intricately linked to the heightened prevalence of forest pathogens with significant damage potential in Europe, necessitating careful consideration and strategic adaptation within management practices of fir forests. Full article

European forests are facing ongoing climate change, and certain tree species are being critically impacted. The Norway spruce (Picea abies (L.) Karst.) is one of the most sensitive species to climate fluctuations, a fact manifesting itself through massive dieback resulting in a lack of high-quality timber and timber market destabilization. Therefore, the possibility of wood substitution with non-native spruce species, namely, black spruce (Picea mariana (Mill.) Britt., Sterns, et Poggenburg), Serbian spruce (Picea omorika (Pančić) Purk.), and blue spruce (Picea pungens Engelm.), under the specific conditions of forest reclamations with great potential for future afforestation was tested. Wood density, modulus of rupture, and modulus of elasticity were used to evaluate wood quality in comparison with native Norway spruce. The results confirmed that only the Serbian spruce reached the quality of Norway spruce and even exceeded it in terms of wood density (P. omorika 525 kg·m⁻³ vs. P. abies 517 kg·m⁻³) and exhibited comparable parameters with regard to other properties. The density of the other species was significantly lower for blue spruce (476 kg·m⁻³) and black spruce (468 kg·m⁻³). A similar trend was found for other wood parameters, which confirmed that Norway spruce quality was nearly comparable with that of Serbian spruce. On the other hand, black spruce and blue spruce did not match the quality of Norway spruce. The within-stem variability of the properties tested was low for all the spruce species examined. In conclusion, the Serbian spruce showed great potential for future usage in forest management and is one of the possible methods of Norway spruce replacement in times of unprecedented forest disturbances under the effects of global climate change. Full article

From an economic perspective, Scots pine (Pinus sylvestris L.) is one of Europe’s most important tree species. It is characterized by its wide ecological adaptability across its natural range. This research aimed to evaluate the forest structure, productivity and especially radial growth of heterogenous pine stands in 16 research plots in the Czech Republic, Poland, Spain and Great Britain. The study assessed the tree-ring formation and its relationship to climate change for each country, using 163 dendrochronological samples. The stand volume of mature pine forest ranged between 91 and 510 m³ ha⁻¹, and the carbon sequestration in the tree biomass was 40–210 t ha⁻¹. The stands had a prevailing random distribution of trees, with a high vertical structure close to selection forests (forest stands with typical very diverse height, diameter and age structure). Spectral analyses showed a substantial decrease in fluctuations in the tree-ring index and a loss in natural growth cyclicity in the last thirty years. The results also evinced that mean air temperature was the most important factor influencing the radial growth compared to precipitation totals. Pine thrives in precipitation-stable locations, as shown by the results from Great Britain. The conclusions of this study confirm the fundamental effect of ongoing global climate change on the dynamics and growth of pine forests in Europe. Full article

Forest ecosystems in Sri Lanka are under pressure from intensive human activity and climate change. Invasive species are one of the greatest threats to autochthonous species and ecosystems. In Bundala National Park of Sri Lanka, there are efforts to control and limit the spreading of unwanted invasive Prosopis juliflora (Sw.) DC. and Opuntia dillenii (Ker-Gawl.) Haw., which poses a significant risk to natural ecosystem conservation. Nine different treatment variants (four replications) were used to test which management approach provides the control of Prosopis juliflora. This research is based on nine repeated measurements from 2017 to 2021 on 36 permanent research plots (each 625 m²) with 27 observed plant species and a total of 90,651 recorded plant individuals. The results confirmed that the dynamics of species richness, heterogeneity, and evenness showed significant differences between treatments during the five years of dynamics. The lowest species diversity was found in the control variant, followed by treatments based on the hard pruning and thinning of Prosopis juliflora trees. In contrast, strategies emphasizing the complete uprooting of Prosopis juliflora trees, replanting, and support of the natural regeneration of native species showed high species diversity and a high overall number of plant species. Generally, treatments had a significant effect on species diversity and the number of individuals of Prosopis juliflora, while changes in the overall number of plant species were more affected by time and succession. Silvicultural treatments including pruning, uprooting, and thinning have proven to be essential tools for nature conservation across various sites, aimed at enhancing habitat diversity in the face of ongoing climate change. Full article

Turkey oak (Quercus cerris L.) is a thermophilic oak species that is gaining importance in the context of ongoing climate change because of its better resistance to climatic extremes and drier conditions. Therefore, this article focuses on Turkey oak’s role and growth properties in the coppice forests of Southern Europe (Italy, Bulgaria) compared to similar site conditions in Central Europe (Slovakia, Czechia). The aims are to evaluate the basic dendrometry indicators, stand biodiversity, growth dynamics, and the effect of climatic factors on tree-ring increment on specific site chronologies. We found that the tree density in coppices of 50–60 years varied between 475 and 775 trees ha⁻¹, and the stand volume ranged from 141 to 407 m³ ha⁻¹. The complex stand diversity of all plots ranged from a monotonous to uniform structure. The size of tree-ring growth was closely related to indicators of stand density. The lowest influence of climatic factors on tree-ring growth was found in sites in Italy and the highest in Slovakia. The primary limiting factor for growth was the lack of precipitation during the growing season, especially in June and July. In contrast, temperature had a marginal effect on radial growth compared to precipitation. The radial growth in research plots in Southern Europe goes through longer 6 to 8-year growth cycles, and in Central European sites, it goes through shorter cycles of 2.4 to 4.8 years, which confirms better growth conditions in this region. The studied coppice stands exhibit a stable reaction to climate change. Yet, regarding cyclical growth, the Central European stands benefit from an advantageous climate and grow better than in Southern Europe. As part of the changing environmental conditions, Turkey oak is becoming an important tree species that can achieve high production potential even in drier habitats due to its regeneration characteristic as coppice and may play a critical role in its northerly introduction in Europe. Full article

As a result of climate change, Norway spruce (Picea abies [L.] Karst.) is dying across Europe. One of the primary reasons for this is the cultivation of unsuitable spruce provenances and ecotypes. This study deals with the growth and genetics of the ecotypes of Norway spruce, the most important tree species of the Czech Republic. At the study site, namely Cukrák, an experimental site was established in 1964 to plant three basic spruce ecotypes: low-elevation (LE), medium-elevation (ME) and high-elevation (HE) ecotype. A dendrometric inventory, dendrochronological sampling and genetic analyses were carried out on individual trees in 45 to 46 years old spruce stands. The ME ecotype was the most productive in terms of its carbon sequestration potential, while the HE ecotype had the lowest radial growth. All ecotypes exhibited a noteworthy negative correlation between tree-ring growth and seasonal temperature, annual temperature, previous year September to current year August temperature, June to July temperature, as well as individual monthly temperatures from previous May to current August. The relationship of annual and seasonal precipitation to growth was significant only for the LE and ME ecotypes, but precipitation from previous year September to current year August and precipitation from current June to July were the most significant for all ecotypes, where the ME had the highest r value. The HE ecotype does not adapt well to a dry climate and appears to be unsuitable compared to the other ecotypes under the studied conditions. This study also documented intra-population genetic variation within years of low growth, as evidenced by significant clonal heritability. The selection of the appropriate spruce ecotypes is essential for the stability and production of future stands and should become an important pillar of forest adaptation to climate change. Full article

Norway spruce (Picea abies (L.) Karst.) is a significant conifer tree species in Europe that holds significant economic and ecological value. However, it remains one of the most sensitive to climate change. This study describes the climate–growth relationship, focusing on dendroecology in hilly spruce forests (319–425 m a.s.l.) located in Bohemia, the Czech Republic, during 1950–2018. The results confirmed that the highest radial increment was obtained in locations with higher precipitation (Kostelec), while the lowest growth was observed in locations with lower precipitation (Karlstejn). Tree-ring growth shows very low increments for the years 1964 and 1976 for all plots, and the years with the least growth were confirmed by the negative pointer year analysis. This study confirmed precipitation as the main factor that affects the growth of spruce at lower altitudes. The radial growth for all study sites shows a statistically significant positive correlation with precipitation during the growing season, while no statistically significant values between radial growth and temperature were obtained. This study demonstrates that Norway spruce is affected more by precipitation than temperature, and the results indicate that this conifer is seriously affected by the lack of precipitation at lower altitudes in the Czech Republic, where the species is not native. Full article

Presently, the forests of one of the most economically important tree species in Europe—Norway spruce [Picea abies (L.) Karst.]—have been disrupted and are in rapid decline due to a combination of several natural factors: extreme drought, heatwaves, and secondary damage caused by bark beetle outbreaks. The vulnerability of these forests has increased considerably over the past decade, and remote sensing methods can theoretically improve the identification of endangered forest stands. The main objective was to determine the relationship between remotely sensed characteristics of vegetation (using the normalized difference vegetation index—NDVI) and annual tree-ring growth in 180 trees through precipitation and air temperature. The research was conducted at six research plots in lowland spruce forests (319–425 m a.s.l.) in the central Czech Republic. No significant correlation between NDVI and annual ring width was observed. The primary factor limiting radial growth was lack of precipitation in the growing season; subsequently, spruce trees reacted negatively to air temperatures. A higher correlation with NDVI was observed on sites susceptible to drought, but overall, NDVI and RWI did not show similarities. This result describes that NDVI is a poor indicator for identifying low radial growth in Norway spruce stands on non-native localities in the studied area. Full article

The article dealt with the load-bearing capacity and durability of power line lattice towers designed from weathering steel. Attention was paid in particular to the bolted lap joints. The article evaluates the static and corrosion performance of bolted lap joints in long-term operating towers, and also presents and evaluates design measures that can be applied in the design of new lattice towers, or in the reconstruction of already operating structures. Power line lattice towers are the most extensive realization of weathering steel in the Czech Republic. On the basis of the inspections carried out to evaluate the working life of the transmission towers in operation, it can be stated that a sufficiently protective layer of corrosion products generally developed on the bearing elements of the transmission towers. However, the development of crevice corrosion at the bolted joints of the leg members is a significant problem. In this paper, the corrosion damage of bolted joints was evaluated considering two basic aspects: (1) the influence of crevice corrosion on the bearing capacity of the bolted joint was evaluated, using experimental testing and based on analytical and numerical calculations; (2) appropriate design measures applicable to the rehabilitation of developed crevice corrosion of in-service structures, or the elimination of crevice corrosion in newly designed lattice towers, was evaluated. Calculation analyses and destructive tests of bolted joints show that the development of corrosion products in the crevice does not have a significant effect on the bearing capacity of the joint, provided that there is no significant corrosion weakening of the structural elements, and bolts of class 8.8 or 10.9 are used. The results of the long-term experimental programme, and the experience from the rehabilitations carried out, show that, thanks to appropriate structural measures, specified in detail in the paper, the long-term reliable behaviour of the lattice towers structures is ensured. Full article

Scree forests with large numbers of protected plants and wildlife are seriously threatened by climate change due to more frequent drought episodes, which cause challenges for very stony, shallow soils. The effect of environmental factors on the radial growth of five tree species—European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) Karst.), sycamore maple (Acer pseudoplatanus L.), European ash (Fraxinus excelsior L.), and mountain elm (Ulmus glabra Huds.)—was studied in the mixed stands (105–157 years) in the western Krkonoše Mountains (Czech Republic) concerning climate change. These are communities of maple to fir beechwoods (association Aceri-Fagetum sylvaticae and Luzulo-Abietetum albae) on ranker soils at the altitude 590–700 m a.s.l. Production, structure, and biodiversity were evaluated in seven permanent research plots and the relationships of the radial growth (150 cores) to climatic parameters (precipitation, temperature, and extreme conditions) and air pollution (SO₂, NO_X, ozone exposure). The stand volume reached 557–814 m³ ha⁻¹ with high production potential of spruce and ash. The radial growth of beech and spruce growing in relatively favorable habitat conditions (deeper soil profile and less skeletal soils) has increased by 16.6%–46.1% in the last 20 years. By contrast, for sycamore and ash growing in more extreme soil conditions, the radial growth decreased by 12.5%–14.6%. However, growth variability increased (12.7%–29.5%) for all tree species, as did the occurrence of negative pointer years (extremely low radial growth) in the last two decades. The most sensitive tree species to climate and air pollution were spruce and beech compared to the resilience of sycamore and ash. Spectral analysis recorded the largest cyclical fluctuations (especially the 12-year solar cycle) in spruce, while ash did not show any significant cycle processes. The limiting factors of growth were droughts with high temperatures in the vegetation period for spruce and late frosts for beech. According to the degree of extreme habitat conditions, individual tree species thus respond appropriately to advancing climate change, especially to an increase in the mean temperature (by 2.1 °C), unevenness in precipitation, and occurrence of extreme climate events in the last 60 years. Full article

The impact of solar cycles on forest stands, while important in the development of the forest environment during climate change, has not yet been sufficiently researched. This work evaluates the radial growth of European beech (Fagus sylvatica L.) in the mountain areas of southern Italy and central Europe (Czech Republic, Poland) in correlation to solar cycles (sunspot number), extreme climatic events, air temperatures and precipitation totals. This research is focused on the evaluation of the radial growth of beech (140 dendrochronological samples with 90–247 years of age) from 1900 to 2019. The time span was divided into the following three periods: (1) a period of regular harvesting (1900–1969), (2) a period of air pollution crisis (1970–1985) and (3) a period of forest protection (1986–2019). The results indicate that the solar cycle was significantly involved in radial growth on all research plots. With regard to the evaluated precipitation totals, seasonal temperatures and the sunspot number, the latter was the most significant. Temperatures had a positive effect and precipitation had a negative effect on the radial increment of beech in central Europe, while in southern Italy, the effect of temperature and precipitation on the increment is reversed. In general, the limiting factor for beech growth is the lack of precipitation during the vegetation season. The number of negative pointer years (NPY) with an extremely low increment rose in relation to the decreasing southward latitude and the increasing influence of climate change over time, while a higher number of NPY was found in nutrient-richer habitats compared to nutrient-poorer ones. Precipitation and temperature were also reflected in the cyclical radial growth of European beech. The relationship between solar cycles and the tree ring increment was reversed in southern Italy and central Europe in the second and third (1970–2019) time periods. In the first time period (1900–1969), there was a positive relationship of the increment to solar cycles on all research plots. In the tree rings of European beech from southern Italy and central Europe, a relationship to the 11-year solar cycle has been documented. This study will attempt to describe the differences in beech growth within Europe, and also to educate forest managers about the relevant influence of solar cycles. Solar activity can play an important role in the growth of European beech in central and southern Europe, especially during the recent years of global climate change. Full article