Forest Sciences

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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.