Forest Sciences

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    Sufficient conditions for rapid range expansion of a boreal conifer
    (Springer Nature, 2022-08-10) Dial, Roman J.; Maher, Colin T.; Hewitt, Rebecca E.; Sullivan, Patrick F.
    Unprecedented modern rates of warming are expected to advance boreal forest into Arctic tundra, thereby reducing albedo, altering carbon cycling and further changing climate, yet the patterns and processes of this biome shift remain unclear. Climate warming, required for previous boreal advances, is not sufficient by itself for modern range expansion of conifers forming forest–tundra ecotones. No high-latitude population of conifers, the dominant North American Arctic treeline taxon, has previously been documented advancing at rates following the last glacial maximum (LGM). Here we describe a population of white spruce (Picea glauca) advancing at post-LGM rates across an Arctic basin distant from established treelines and provide evidence of mechanisms sustaining the advance. The population doubles each decade, with exponential radial growth in the main stems of individual trees correlating positively with July air temperature. Lateral branches in adults and terminal leaders in large juveniles grow almost twice as fast as those at established treelines. We conclude that surpassing temperature thresholds, together with winter winds facilitating long-distance dispersal, deeper snowpack and increased soil nutrient availability promoting recruitment and growth, provides sufficient conditions for boreal forest advance. These observations enable forecast modelling with important insights into the environmental conditions converting tundra into forest.
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    Emerging signals of declining forest resilience under climate change
    (Springer Nature, 2022-07-13) Forzieri, Giovanni; Dakos, Vasilis; McDowell, Nate G.; Ramdene, Alkama; Cescatti, Alessandro
    Forest ecosystems depend on their capacity to withstand and recover from natural and anthropogenic perturbations (that is, their resilience)1. Experimental evidence of sudden increases in tree mortality is raising concerns about variation in forest resilience2, yet little is known about how it is evolving in response to climate change. Here we integrate satellite-based vegetation indices with machine learning to show how forest resilience, quantified in terms of critical slowing down indicators3,4,5, has changed during the period 2000–2020. We show that tropical, arid and temperate forests are experiencing a significant decline in resilience, probably related to increased water limitations and climate variability. By contrast, boreal forests show divergent local patterns with an average increasing trend in resilience, probably benefiting from warming and CO2 fertilization, which may outweigh the adverse effects of climate change. These patterns emerge consistently in both managed and intact forests, corroborating the existence of common large-scale climate drivers. Reductions in resilience are statistically linked to abrupt declines in forest primary productivity, occurring in response to slow drifting towards a critical resilience threshold. Approximately 23% of intact undisturbed forests, corresponding to 3.32 Pg C of gross primary productivity, have already reached a critical threshold and are experiencing a further degradation in resilience. Together, these signals reveal a widespread decline in the capacity of forests to withstand perturbation that should be accounted for in the design of land-based mitigation and adaptation plans.
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    The introduction of red oak (Quercus rubra L.) in Ukrainian forests: advantages of productivity versus disadvantages of invasiveness
    (Sciendo (De Gruyter), 2022-12-10) Hayda, Yuriy; Mohytych, Vasyl; Bidolakh, Dmytro; Kuzovych, Vasyl; Sułkowska, Małgorzata
    The history and dynamics of the introduction of red oak into forest plantations in Ukraine are presented. The positive and negative consequences of this artificially introduced species are characterised. The anthropogenic factor of a broad representation of the species and the probability of low natural spread out outside the existing plantations are highlighted. The current data on the area of red oak plantations by administrative regions, forest categories, types of forest site conditions and age classes in Ukraine are indicated. The possibility of controlling and limiting the adverse invasive effects of red oak representation in forest stands is pointed out. It is recommended to conduct detailed and systematic interdisciplinary research on the degree of red oak invasiveness impact in Ukraine and effective forest care treatments for controlling its negative role.
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    Height–diameter relationship of plantation-grown juvenile black locust trees is differentiated according to their growth rate, which is positively affected by spacing
    (Sciendo (De Gruyter), 2022-12-10) Stankova, Tatiana; Dimitrova, Proletka; Gyuleva, Veselka; Stefanova, Penka
    The main objective of this study was to explore the height–diameter relationship of plantation-grown juvenile black locust trees and to clarify if the tree height can be adequately predicted at stand level from the breast-height diameter and which is the most appropriate functional form; if the predictions can be expanded to a wider region by mixed-effects modelling and which is the most relevant level for model localisation; if the random parameter components can be calibrated with stand-level variables and which of them is an appropriate predictor. We first fitted seven one-predictor models at plot level and we selected the most adequate simple function according to a set of goodness-of-fit criteria. It was then approximated over the entire data set in nine different mixed-effects model forms that were compared by Likelihood Ratio Test. Calibrations of the random parameter component of the best mixed-effects model with a height–diameter measurement of one tree at each occasion and with a function of a plantation-level variable were attempted. Our study derived a mixed-effects and a two-predictor deterministic models, based on an exponential function of the reciprocal value of the diameter, with a constant intercept of 1.3. Height–diameter relationship localisation at plot level, regardless the geographic region, was most suitable for the investigated juvenile black locust data. The specific component of the rate parameter in the mixed-effects model form differentiated the plantations according to their growth potential. A positive correlation between the height increase and the growing space was also distinguished that allowed calibration of the mixed-effects rate parameter by a linear function of spacing to develop a two-predictor deterministic function. However, the mixed-effects model showed higher predictive power than the purely deterministic relationship.
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    Degradation of mycorrhizal fungal communities associated with cork oak and understory vegetation by the anthropogenic factors
    (Sciendo (De Gruyter), 2022-09-22)
    The cork oak (Quercus suber L.) forests are ecosystems of high environmental and socioeconomic value in the Mediterranean basin. However, in Algeria, the cork oak forests are highly threatened by repeated fires, overgrazing and the anthropogenic pressure that weaken the ecosystem of cork oak and affect its natural regeneration. This degradation results in an alteration of many ecological components of the cork oak, such as fungal communities in the soil. Thus, the aim of this work is to study the effects of cork oak stand degradation on the diversity of mycorrhizal communities associated with Quercus suber and some of its understory shrubs (Cistus monspeliensis, Lavandula stoechas and Thymus vulgaris) in the forest of Brabtia (northeastern Algeria).For this purpose, two sites were chosen: one degraded by the anthropogenic factors and the other non-degraded one. Moreover, it is suggested that some plants of the understory shrub vegetation of cork oak, such as the cistus, lavender and thyme, prove to be favourable to the juvenile growth of this tree. The results obtained showed that the ectomycorrhizal (EcM) root colonization of cistus was higher compared to that of cork oak in both stations. The estimation of arbuscular mycorrhizal (AM) colonization showed significantly higher levels in the roots of cork oak, cistus, lavender and thyme in the degraded station compared with the non-degraded stations. In contrast, the rhizosphere soils of cork oak and cistus had low number of AM propagules and fungal spores, while under the roots of lavender and thyme, these two parameters were greatly improved with the abundance of the genera Glomus and Gigaspora. These results underline the need to take into account the plant–fungus interactions in the development of restoration strategies of the degraded soils and forest ecosystems
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    Lelliottia nimipressuralis (Carter 1945) Brady et al. 2013 as the causative agent of bacterial wetwood disease of common silver fir (Abies alba mill.)
    (Sciendo (De Gruyter), 2022-09-22) Kulbanska, Ivanna M.; Plikhtyak, Petro P.; Shvets, Maryna V; Soroka, Myroslava I.; Goychuk, Anatoliy F
    In recent decades, in many regions of the planet, there has been a widespread deterioration in the health condition and dieback of dark coniferous forests, caused by the combined action of various stress factors of biotic and abiotic origin. Forests with the participation of species of the genus Abies Mill. are particularly prone to degradation and dieback. The aim of the research is to study the symptoms of bacterial wetwood disease of Abies alba in the Ivano-Frankivsk region (state enterprise ‘Kutske forestry’) and to determine the anatomical, morphological and cultural properties of the pathogen. Some of the common symptoms of the disease include cracks and ulcers on the trunks with exfoliated rhytidome and exudate secretion, massive development of epicormic shoots, saturated xylem and phloem, wet rot with a characteristic odour of fermentation and pathological nucleus. Based on the syntaxonomic analysis of fir forests, an attempt has been made to identify the objective causes that lead to excessive development of phytopathogens and dieback of Abies alba. Our research established that the primary cause of dieback of Abies alba Mill. forests is a systemic, vascular–parenchymal disease known as bacterial wetwood of fir, which affects all plant tissues at all stages of ontogenesis. We isolated and experimentally confirmed that the causative agent of the disease is a phytopathogenic bacterium Lelliottia nimipressuralis (Carter 1945) Brady et al. 2013, which also causes bacterial wetwood in many species of forest woody plants, and also studied its common morphological, physiological and biochemical properties.
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    Coleopterous predators of pine bark beetles in the last years of the outbreak recorded in Ukraine
    (Sciendo (De Gruyter), 2022-09-22) Meshkova, Valentyna; Vorobei, Alla; Omelich, Anastasiya
    The purpose of this study was to identify the species composition of coleopterous predators and their occurrence in different parts of the stem depending on the health condition of Scots pine (Pinus sylvestris L.) in the collapsing foci of bark beetles (Coleoptera: Curculionidae: Scolytinae). The research was carried out in 2019–2021 at 38 sample plots located in five State Forestry Enterprises of Sumy region (Ukraine). All sample plots are located in pure Scots pine stands in relatively poor forest site conditions. The relative density of stocking is 0.6–0.7, and the age of stands is between 60 and 110 years. The health condition for each tree was evaluated on visual characteristics by the classes: first – healthy; second – weakened; third – severely weakened; fourth – drying up; fifth – recently died and sixth – died over a year ago. Bark beetles’ nuptial chambers and predators were counted on 25 × 25 cm pallets, which were located at the lower, middle and upper parts of the stem with thin, thick and transitional bark, respectively. The significance of differences in the performance of predator species depending on the tree part, health condition and year was analysed using the nonparametric Kruskal–Wallis (K–W) test. The species composition of predators in different years, stem parts and tree health condition was compared using the Sorensen–Chekanovsky index. In the collapsing foci of bark beetles, the health condition of Scots pine in 2019–2021 tended to worsen. The infestation density of Ips acuminatus (Gyllenhal, 1827) and Ips sexdentatus (Boerner, 1767) was 0.62 ± 0.032 and 0.64 ± 0.017 nuptial chambers per 1 dm2, respectively, and also decreased in 2019–2021. In the galleries of bark beetles, seven species of coleopterous predators were collected: Aulonium ruficorne (Olivier, 1790) (Zopheridae), Platy soma elongatum (Leach, 1817) (Histeridae), Rhizophagus depressus (Fabricius, 1792) (Monotomidae), Corticeus pini (Panzer, 1799) (Tenebrionidae), Thanasimus formicarius (Linnaeus, 1758), Thanasimus femoralis (Zetterstedt, 1828) (Cleridae) and Salpingus ruficollis (Linnaeus, 1761) (Salpingidae). Two more species – Glischrochilus quadripunctatus (Linnaeus, 1758) (Nitidulidae) and Pytho depressus (Linnaeus, 1767) (Pythidae) – were singly collected in the foci. T. formicarius and P. elongatum were the most abundant. The ratio of predator–prey significantly increased from the upper to the lower part of the stem with thick bark. It, however, decreased in this stem part from the fourth to the sixth class of the health condition of the host tree.
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    Comparison of vascular plants in herb layers of ecotones in urban and non-urban forests in Brzesko city (Polish Carpathian foreland)
    (Sciendo (De Gruyter), 2022-09-22) Fornal-Pieniak, Beata; Mandziuk, Agnieszka
    Nowadays, human influence is more noticeable in urban and non-urban ecosystems, which, in turn, leads to the transformation of valuable natural resources. This article presents a study on the diversity of species composition of the vascular herb layer species of ecotones in selected urban forests of the city of Brzesko and in forests outside the city. All forests represented the association of oak–hornbeam plant. The results showed that there are inconsistent and consistent vascular plant species with the Tilio-Carpinetum habitat in urban and non-urban forests. Plant species were significantly (c2 test, p < 0.05) found more frequently in the herb layer of non-urban forests than in urban forests. This proves, among other things, that the influence of anthropogenic activity is more on these objects than in forests outside the city.
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    Conversion of low-value stands by corridor method in Left-Bank Forest-Steppe, Ukraine
    (Sciendo (De Gruyter), 2022-09-22) Vedmid, Mykola; Luk’yanets, Volodymyr; Tarnopilska, Oksana; Rumiantsev, Maksym; Kobets, Oleksii; Obolonyk, Iryna; Pozniakova, Svitlana; Musienko, Sergiy
    The aim of the study was to identify the influence of different widths and cardinal directions of felled corridors on the condition and mensuration characteristics of the English oak trees planted there during the conversion of low-value young stands using the corridor method. The study was carried out in oak forests in the forest-steppe zone at a permanent sample plot. The experiment included the conversion of a low-value 8-year-old stand to improve its species composition. The sample plots were laid out in a fertile hardwood forest site. The conversion was realised by felling corridors of various widths (6, 9 and 12 m) and directions and planting English oak trees (Quercus robur L.) within them in rows. For the planted oaks, tending felling was carried out three times: weeding (8 years), cleaning (13 years) and thinning (32 years). A comparative analysis of mensuration characteristics (average height, diameter, growing stock, radial increment, health condition, etc.) was carried out for 32-year-old oak trees grown in the corridors and a part of a low-value stand in the unfelled strips after the tending felling. It was found that the average height and diameter at breast height of oaks in the 6, 9 and 12 m wide corridors of different cardinal directions did not differ significantly. The difference in oak stocks within 6 and 9 m wide corridors of different cardinal directions was also insignificant. The stock differences were statistically significant for 6 and 12 m wide corridors as well as for 9 and 12 m wide ones. The article made recommendations on the width of felled corridors and unfelled strips to effectively convert low-value young stands by the corridor method.
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    Peatlands restorer plant species in the protected forest area
    (Sciendo (De Gruyter), 2022-05-27) Nursanti, Nursanti; Novriyanti, Novriyanti; Indriyani, Arisa Dwi; Anggraeni, Nurul; Paiman, Asrizal
    Like other ecosystems, burnt peatlands will run into natural regeneration, characterized by pioneer plants’ presence as a succession process guard. However, annual burnt peatlands can complicate vegetation growth, including the pioneer’s presence. Besides that, it is unknown what kind of grow pioneers are, so the research aims to find out the pioneer plants’ diversity on burnt peatlands is essential. The reasonably extensive distribution of peat ecosystems and high fire potential in Sumatra is Tanjung Jabung Regency of Jambi Province selected to study. The locations of plant species inventory are Orang Kayo Hitam Forest Park (burnt five times), village forest (HD) Sinar Wajo, and HD Koto Kandis Dendang (each burnt once) using the Nested Quadrat and Line Transect of vegetation survey method. Vegetation analysis showed that 22 pioneers were found in HD Sinar Wajo and 27 species in HD Koto Kandis Dendang. Some are identified as ferns (Pteridophyta), breed with spores, and pioneer plants reproduce by seeds (Spermatophyta). In Orang Kayo Hitam Forest Park found 26 species consisting of plants, trees, shrubs, and lianas. Among the three locations, we found the same type of pioneer. It is implied that patterns and regeneration processes can help each other in the same landscape.
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    Growth and formation of Scots pine stands in Eastern Polissia of Ukraine
    (Sciendo (De Gruyter), 2022-05-27) Zhezhkun, Anatoly М.
    The purpose of the research is to study the current state, features of growth and formation of Scots pine (Pinus sylvestris L.) stands in Eastern Polissia of Ukraine. The structure of pine stands by origin, age, the density of stocking, site indices, forest types and health condition was analysed. Features of the formation of stands were studied at the permanent sample plots. Visual assessment of health condition, as well as signs of pest and disease damage of trees, other defects and external signs that caused stem defects was carried out. The age structure of pine stands was not optimal: there was an excess of mature stands and a lack of young stands. The health condition of mixed pine stands was relatively better than that of pure pine stands. Mixed pine stands were characterised by high biological resistance and accumulated significant wood stock under regular sylvicultural maintenance. The dynamics of forestry and evaluation indicators of reference pine stands were evaluated and comparison of their growth with stocked pine stands was performed.
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    Prospects of cultivation of Jack pine (Pinus banksiana Lamb.) on sandy soils of natural–technogenic origin in Kyiv Polissia
    (Sciendo (De Gruyter), 2022-05-27) Brovko, Fedir; Yukhnovskyi, Vasyl; Brovko, Dmytro; Brovko, Оlha; Minder, Victoria; Urliuk, Yurii
    The aim of the research was to identify the influence of environmental factors inherent in the alluvial and displaced sands of the study region on the growth of the Jack pine and the prospects for its cultivation. We found that the success of growth of Jack pine seedlings on sandy soils depends on a set of factors, which include the presence or absence, in the rhizosphere of sand, of humus impurities and genetic horizons of zonal soils, silty or loamy layers, soil density and composition of pine stands formed in the cultivation. On alluvial sands, sparse forests of Jack pine and Scots pine with a density of 0.3 units were formed. The yield of seeds from Jack pine cones was 1–2% higher than the normative values, and the mass of 1000 seeds was 50% higher. Jack pine seedlings grow according to I class of productivity on displaced sands, with an admixture of humus mass and remnants of genetic horizons of zonal soils at the root depth. In the rhizosphere of the stand, the roots of Jack pine seedlings occupied 78% of the mass of all roots that inhabited a metre-thick sand. Jack pine seedlings that fall under the canopy of Scots pine fall out of the plantations due to drying, which indicates their demand for light and appropriateness of growing Jack pine in solitary plantings or in mixed low-density plantations with Scots pine.
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    Formation of European beech stands (Fagus sylvatica L.) that involve Scots pine (Pinus sylvestris L.) in tree species composition in the Ukrainian Roztochie
    (Sciendo (De Gruyter), 2022-05-27) Myklush, Yuriy; Myklush, Stepan; Debryniuk, Iurii; Hayda, Yuriy
    Productive European beech stands (Fagus sylvatica L.) involving Scots pine (Pinus sylvestris L.) are formed in Ukrainian Roztochie. Considering value and limited distribution of beech stands involving pine in tree species composition, it is necessary to work out and implement measures for their natural restoration in connection with the climate change and the efficient use of raw materials and non-wood products. Main forestry and management indices of beech stands that include pine in tree species composition were analysed. Forestry activities that are currently carried out in middle-aged and maturing stands significantly reduce their relative completeness and growing stocks, as determined by comparing growth particularities of productive beech stands from different sources.
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    Xylophagous beetles (Coleoptera) in the zones of Gomilshanski lisy National Nature Park with different management regime
    (Sciendo (De Gruyter), 2022-05-27) Meshkova, Valentyna; Skrylnik, Yuriy; Bieliavtsev, Maxim; Zinchenko, Olga; Borysenko, Oleksandr; Markina, Tetiana
    The purpose of the research was to assess the species composition and biodiversity indices for xylophagous beetles collected by window traps in the parts of Gomilshanski lisy National Nature Park with different management regimes and anthropogenic load. Four window traps were placed in each of the five groups of sample plots: clear felling, selective felling, stationary recreation, regulated recreation and protected zone. The data were analysed using the statistical software package PAST, particularly, the Menhinick index (DMn) and dominance index (D) were evaluated and classical clustering (unweighted pair-group average [UPGMA]) was performed. A total of 42 species of xylophages (9903 individuals) were collected from Curculionidae (Scolytinae and Cossoninae), Cerambycidae, Histeridae, Bostrichidae, Buprestidae and Lymexilidae. The highest species richness was in the plots of clear and selective felling (25 and 22 species, respectively) and the lowest was in the protected zone (16 species), regulated recreation (19 species) and stationary recreation (22 species). The Menhinick index (DMn) was the lowest in the protected zone (0.27), increased in the zone of regulated recreation (0.43) and stationary recreation (0.45) and was maximal in the plots of selective and clear felling (0.69 and 0.77, respectively). The number of individuals was maximal in the protected zone and minimal at the plots of selective and clear felling. All sites were dominated by Xyleborinus saxesenii (Ratzeburg, 1837) (66–85% individuals) and Anisandrus dispar (Fabricius, 1792) (8.5–20.7% individuals). Minimal dominance (0.49) was found in the plot of clear felling. Cluster analysis showed similarity of the xylophage complex in the plots of clear and selective felling, as well as in the zone of stationary and regulated recreation, which differed from the protected zone.
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    Genetic characterisation of centuries-old oak and linden trees using SSR markers
    (Sciendo (De Gruyter), 2022-03-11) Bilous, Svitlana; Prysiazhniuk, Larysa; Chernii, Snizhana; Melnyk, Serghii; Marchuk, Yurii; Likhanov, Artur
    The main goal of this study was to identify the unique gene pool of old and historically valuable Quercus robur L. and Tilia cordata L. to be able to characterise their genetic diversity in order to determine the polymorphism by expressed sequence tag-single sequence repeat (EST-SSR) markers and identify the most valuable specimens. Morphological description, molecular genetic analysis, and statistical analysis were used in studies. The genetic distances between old-value trees of different Quercus L. and Tilia L. were determined based on EST-SSR markers and morphological characteristics. Using polymerase chain reaction (PCR), alleles of the expected size were obtained. It was determined that four to eight alleles were obtained by seven SSR markers in the studied Q. robur L. samples. According to the calculated value of the locus polymorphism index (polymorphism information content [PIC]), the most polymorphic was the marker SSRQrZAG 65; the PIC was 0.84. The lowest value of PIC was observed in the marker SSRQrZAG 11; the PIC was 0.69. Intragenetic polymorphism was detected for all studied markers. Among the studied samples of linden, two to five alleles were identified. It was found that the highest value of PIC was obtained for the marker Ts920 – 0.72. The least polymorphic was the marker Ts927 (PIC was 0.28), which is not only due to the small number of alleles, but also their uneven distribution in the sample. Intragenetic polymorphism was detected in four of the six markers analysed for T. cordata L. In this study, polymorphism was detected in all studied samples of Q. robur L. and T. cordata L., which allows to assess their genetic diversity based on the distribution of alleles.
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    Correlations among morphological traits of sweet chestnut (Castanea sativa Miller) from Bosnia and Herzegovina
    (Sciendo (De Gruyter), 2022-03-11) Tuğ, Aida; Hodžić, Mirzeta Memišević; Ballian, Dalibor
    Sweet chestnut forests in Bosnia and Herzegovina are underrepresented in the total forest fund, and their area is declining today. The research aims to determine the correlation relations of morphological traits of chestnut leaves, fruit and cupule in the population of Bosnian Krajina (northwestern Bosnia and Herzegovina) to undertake selection and breeding activities. Eleven traits of fruits, leaves and cupules were measured, seven assessed and six calculated. A mutual correlation for the researched traits was calculated using the Pearson correlation coefficient r. When the fruit traits and cupule traits were compared, the needle length showed a statistically significant correlation with most of the fruit traits. The traits of the number of fruits in the cupule and needle length had a statistically significant correlation coefficient with leaf blade width and leaf petiole length. The correlated traits can be distinguished as important for further selection and breeding of sweet chestnuts. The research results indicate that the genetic material of sweet chestnut is a rich source of genetic diversity and can be used in selection to obtain new varieties and cultivars in Bosnia and Herzegovina and for the protection of the indigenous gene pool.
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    Dynamics of non-structural carbohydrates in Pinus pallasiana D. Don needles under different forest growth conditions of ravine anti-erosion plantations
    (Sciendo (De Gruyter), 2022-03-11) Bessonova, Valentina; Yakovlieva-Nosar, Svitlana
    The research was aimed at analysing the peculiarities of non-structural carbohydrate metabolism in the needles of Pinus pallasiana D. Don in anti-erosion plantations on the slope and in the thalweg of the Viyskovyi ravine under different forest growth conditions. The ravine is located in the Dnipropetrovsk region and belongs to the southern geographical variant of ravine forests. The studied plants grew at three experimental sites of man-made plantation: in the thalweg (forest growth conditions – mesophilic, fresh, CL2), in the middle part of the slope of the southern exposure (mesoxerophilic, somewhat dry, or semi-arid, CL1) and on the upper part of this slope (xerophilic, arid, CL0–1). Changes in glucose, fructose, reducing sugars, sucrose and starch during the period from May to October were studied. The concentration of osmotically active substances (glucose, sucrose) increases in the months with the most unfavourable hydrothermal parameters, especially in plants of mesoxerophilic and xerophilic forest growth condi tions. The dynamics of fructose content revealed two maxima (July and October), when the concentration of glucose tends to increase steadily, with the highest values found in October. During the study period, the level of fructose in the needles under the arid conditions of the upper and middle parts of the slope was much lower than under the fresh conditions of the thalweg. The dynamics curve of the starch content tends to decrease from the maximum values in May to the first minimum in August. It is followed by some increase in the concentration of this polysaccharide that does not reach the previous values. The second minimum is registered in October. Such changes in the level of starch in the needles of plants are observed under all forest growth conditions. The decrease in polysaccharide content is consistent with the increase in glucose and sucrose, especially in August. A more significant increase in the concentration of soluble osmoprotective sugars (glucose, sucrose) in P. pallasiana needles under unfavourable hydrothermal conditions compared to normal moisture conditions indicates the ability of plants to adapt to mesoxerophilic and xerophilic conditions.
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    Effect of meteorological factors on the radial growth of pine latewood in northern taiga
    (Sciendo (De Gruyter), 2022-03-11) Neverov, Nikolay; Chistova, Zinaida; Mineev, Alexandr
    The purpose of this study is to evaluate the influence of day and night meteorological parameters (air temperatures and dew points, relative humidity, wind speed and precipitation) on the radial growth of pine latewood in northern taiga, in typical conditions of its growth. The study was conducted in the north of the Arkhangelsk region (Russia). A total of 63 cores were selected from seven most representative sites. Meteorological parameters were obtained from the WMR 918 H digital weather station (Huger GmbH, Germany), located directly on the study area and operating in monitoring mode. The analysis used meteorological data for the period 2008–2015. Correlation with night and day air temperature in June and July (0.72–0.77) was revealed in blueberry type. In all the stands studied, a reliable correlation with wind speed was established, direct (0.77‒0.88) and inverse (−0.7 to −0.99), but each sample plot had an individual dependence. A reliable correlation with the humidity of August and September (0.64–0.87) and an inverse correlation with precipitation in May and August (−0.63 to −0.75) were established. In general, pine in blueberry, cowberry and pine on swamp types have a similar reaction to the variability of meteorological factors, the most important of which is the temperature regime of air and wind speed.
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    The results of the introduction of twisted pine (Pinus contorta) in Bolshoy Solovetsky Island
    (Sciendo (De Gruyter), 2022-03-11) Sobolev, Alexandr; Feklistov, Pavel; Bolotov, Ivan; Barzut, Oksana
    In the central part of the Bolshoy Solovetsky Island, in the same type of growing conditions, two plots were created in 1988: the first consisted of twisted pine (Pinus contorta Loud. var. latifolia S. Wats) crops and the second one was of Scots pine (Pinus sylvestris L.). The aim of the study was to establish the morphological parameters of the twisted pine and its growth in the conditions of the Bolshoy Solovetsky Island in comparison with the native spe cies P. sylvestris L. Also, we aimed to identify the features of P. contorta var. latifolia and determine the possibility and necessity of further introduction of the species. The preservation of the twisted pine and scots pine cultures was determined. Accounting trees were selected (62 and 31 trees, respectively), in which morphometric indicators were measured. Wood samples (cores) were taken from them with an age drill to measure radial growth. The radial increment was measured using the MBS-9 microscope and the Lintab device. To measure the increase in height, six medium-sized model trees were cut down. According to the taxation indicators, the two types differed slightly and the differences were most often unreliable. The average height of the twisted pine trees was significantly higher compared to that of Scots pine. The thickness of the bark varied; on average, at the age of 18, it was 1.35 ± 0.038 mm for twisted pine and 1.86 ± 0.095 for Scots pine, that is, the native pine bark was 38% thicker. Typical for twisted pine were a significant number of pathologies noted in 22% of the studied trees. Twisted pine was distinguished by a stronger development of the assimilation apparatus: the number of branches of the first order, the number of branches in the whorl, the life span of needles. An increase in radius (the width of the annual ring) was observed at 14–15 years, and then with age, the value decreased in twisted pine and remained at a consistently high level in Scots pine. The width of the late zone of the annual ring was 12% in Scots pine and 14% in twisted pine; but at a young age, the late wood in twisted pine was very small. The increase in height of the twisted pine was on average less than that of Scots pine. The dependence of the trunk volume on the diameter was almost identical in both species.
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    The damage caused by wind in middle-aged Scots pine stands on permanent thinning experimental plots
    (Sciendo (De Gruyter), 2021-12-11) Zachara, Tadeusz; Gil, Wojciech
    In July 2002, the very strong hurricane appeared in northern Poland, which caused destruction of forest cover of area more than 10,000 ha. The permanent thinning research plot in a 53-year-old pine stand located in Myszyniec forest district (150 km north of Warsaw) was lying on the edge of damaged area. The following treatments were tested on this plot: 1) control plot (without thinning); 2) schematic cut in 20-year-old stand, selective thinning to 40 years, then thinning from below; 3) schematic cut in 20-year-old stand, then selective thinning; 4) selective thinning in young stand (20–40 years), then thinning from below and 5) selective thinning all the time. A significant part of this plot was completely destroyed and in the other part of the plot, some trees survived. A small part of the plot resisted the wind attack. An analysis of the amount of destroyed trees (measured by basal area) showed no differences between particular silvicultural treatments. The level of damage differed between par ticular parts of the plot. Another plot located in Ostrów Mazowiecka forest district (100 km NE of Warsaw) with the same thinning treatments was touched by heavy wind in July 2011 when the stand was 62 years old. Unlike the hurricane of 2002, this storm did not destroy the experimental plot which was located outside the zone of heaviest calamity. Therefore, damage on this plot had point and group character. Although on particular measurement units, share of broken or fallen trees did not exceed 10% of total basal area, it can be observed that the lowest level of damage was noticed on plots with selective thinning in young age and thinning from below in older stand.