The article is focused on microbiological and silvicultural properties of bacterial wetwood of silver birch (Betula pendula), also known as European white birch. During the active phase of the disease, bacterial wetwood (i.e. bacterial dropsy, vascular parenchymatous bacteriosis or flux slime) is characterised by crust and periderm bloating, necrotic wet stains and abundance of exudate. The disease is more likely to occur in older (r = 0.56, p < 0.01) and less-dense (r = −0.29, p < 0.01) stands.The statistical model showed that the chance of bacterial wetwood increases with birch age by 0.36% per year. The stands with birch proportion of over 70% demonstrated 15.3% lower infection rate compared to the stands with lower birch presence. The stands with lower stocking demonstrated a higher proportion of infected tree distribution by 7.5% compared to the stands with higher birch representation. The most vulnerable were larger, older B. pendula trees with longitudinally fissured bark that grow on poorer soils and experience frequent water stress.Birch associations with Pteridium aquilinum and Vaccinium myrtillus were more susceptible to infection (31.6% and 44.3%, respectively), whereas associations with Brachypodium sylvaticum, Sphagnum palustre and Calluna vulgaris were at lower risk. Strong ecological and trophic association of bacterial wetwood was present between silver birch and Tremex spp., particularly Tremex fuscicornis. Mycobiota was represented by Rhizopus microsporus, Mucor mucedo, Penicillium aurantiogriseum, Penicillium purpurogenum and Acremonium strictum.Enterobacter, Xanthomonas, Pantoea and Bacillus spp. associated with bacterial wetwood of silver birch were isolated. Enterobacter nimipressuralis was found to be the primary causative agent through means of artificial infection, while other bacteria were found to be either weak pathogens or concomitant. E. nimipressuralis formed the largest number of colony-forming units (CFU) for bark and cambium (164 and 127 CFU, respectively) and was also found in a small amount as a vital obligate in the automicrobiota in healthy birch trees.

The article presents the symptomatic characteristics of vascular-parenchymal bacteriosis, which is quite common on forest woody plants, caused by the causative agent of bacterial dropsy. It was shown that a characteristic feature of this bacteriosis is the formation of various shapes and sizes of ulcers, in the places of formation of which there is a release of a dark, almost black, exudate. It is emphasized that during the study of the vascular system of common oak trees, its dark coloration is noticeable. Now there is a chronic course of the disease with the presence of dieback of individual branches in the crown. It was established that the causative agent of bacterial dropsy is Lelliottia nimipressuralis; its physiological and biochemical characteristics are given. The aim of the work is the bacteriological study of wood samples with typical signs of bacterial dropsy, study of morphological, cultural and biochemical properties of the causative agent of bacterial dropsy of oak. Methods. Classical microbiological, phytopathological, biochemical, statistical methods were uses in the work. If a bacterial dropsy was suspected, diagnostic methods were combined, with the help of which the etiology of the disease was established: an accurate analysis of symptoms; a thorough microscopic examination of the affected parts of plants; isolation and identification of the pathogen using NEFERMtest24 MikroLaTE, ErbaLachema, API 20E test systems and the like. Results. We have noted the habitual manifestations of the bacterial dropsy of the common oak. From the lesion, where dark brown areas of wood appeared under the bark in the area of the ulcer against the background of healthy light-colored wood, isolated bacterial isolates were identified by morphological and physiological-biochemical properties as Lelliottia nimipressuralis (Brady et al. 2013) – the causative agent of bacterial dropsy of oak (now Enterobacter nimipressuralis). It was found that isolates from common oak, like the collection strain E. nimipressuralis 8791, are gram-negative. It was shown that the studied bacteria are facultative anaerobes and use glucose both under aerobic and anaerobic conditions. They do not form gelatinase and protopectinase. Exhibit a positive Voges-Proskauer reaction. Bacteria use glucose, arabinose, rhamnose, amygdalin, and melibiose as the only source of carbon nourishment. The bacteria do not use inositol and sorbitol. They do not form indole and hydrogen sulfide (H2S), but are capable of reducing nitrates. They contain arginine dehydrolase, ornithine decarboxylase, β-galactosidase, but not lysine decarboxylase, and urease. Conclusions. It has been established that the diseases that we discovered are, by all symptomatic signs, a systemic, vascular-parenchymal bacteriosis, known as bacterial dropsy of oak, which affects all tissues, plant parts and generative organs at all stages of ontogenesis. According to the morphological, physiological and biochemical properties of bacterial dropsy isolated by us during the research, we identified the causative agent of bacterial edema of oak – Lelliottia nimipressuralis (Carter 1945).

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Given the forestry, the ecological and economic value of forests with the participation of Fraxinus excelsior and taking into account the intensive deterioration of their phytosanitary status in modern conditions, a comprehensive study of symptoms, causes, and pathogenesis of ash tuberculosis with further development of effective protection measures, including using biological products based on Bacillus sp. and other myco- and microorganisms, is a particularly relevant area of research. The aim of the research is to identify negative abiotic and biotic factors in the pathology of F. excelsior. In the process of research general scientific and special research methods were used (microbiological, mycological, phytopathological, entomological, and silvicultural-ecological methods). It is emphasized that the pathology of the common ash is a multifaceted phenomenon with interrelated processes of infectious and non-infectious nature, which in recent years has led to epiphytic dieback and now has a tendency to increase. It has been established that tuberculosis of F. excelsior is the most common and harmful disease within the study region and causes more economic than environmental damage. Bacteria of the genera Pseudomonas sp., Erwinia sp., and Xanthomonas sp., as well as micromycetes, which mainly take the place of the concomitant mycobiota. There are five stages (phases) of the development of tuberculosis pathology, which differ significantly in symptoms. The species composition of harmful insects has been identified. It is shown that hydrothermal stress is a catalyst for the epiphytic dieback of common ash. Direct dependence of the spread of tuberculosis on the share of ash in the stands of different age groups was revealed. In the study area, tuberculosis reaches epiphytotics on F. excelsior, especially at a young age. The expediency of distinguishing the causes and pathological processes associated with ash tuberculosis is indicated, so as not to confuse the disease-catalyzing factors and the factors that lead to the complete degradation of ash stands

The results of studies of bacterioses Fraxinus excelsior, Betula pendula, Aesculus hippocastanum, Quercus robur, Pinus sylvestris, Populus alba, Populus tremula, Morus alba, Ailanthus altíssimaare presented. The focus is on that, phytopathogenic bacteria are extremely harmful and directly involved in the epiphytotic dieback of woody plants. To study the symptoms and etiology of bacterial diseases of woody plants in the green zone of the city of Kiev, special methods of forest pathological examinations and phytopathological studies were used, as well as methods generally accepted in experimental microbiology, in particular the selection of affected organs and tissues, isolation of micro-and microorganisms into a pure culture; checking the pathogenic properties of isolated isolates and their identification and the like. It is shown that pathogens of bacterioses of the studied plants are phytopathogenic bacteria-polybiotroph from genus Pseudomonas, Xanthomonas, Enterobacter, Erwinia, Brenneria, Xylella, Rhizobium, Corynebacterium, Bacillus, Clostridiumetc. Symptoms and features of the pathogenesis of ash tuberculosis are given (causative agent-Pseudomonas syringae pv. savastanoi); bacterial dropsy of white birch (causative agent-Lelliottia nimipressuralis), common horse chestnut (causative agent-Pseudomonas syringae var. aesculi), common oak (causative agent-Lelliottia nimipressuralis), white poplar and aspen (bacterial association, in particular Erwinia cancerogena, Corynebacterium humiferum, Bacillus populi), white mulberry (causative agent-Pseudomonas syringae pv. mori), ailanthus, (pathogen not identified); and tumorassociated bacteriosis in pine (causative agent is not identified). The need to deepen studies of pathogenic components of automicrobiota, in particular in the context of understanding both the general biological problems of pathology and the goal of developing forest protection measures, is noted.

Aphyllophoroid macromycetes are a key link in natural and artificial biocenoses, in particular, forest ecosystems. Their peculiarity is due to the variety of morphological forms and the ability to colonise various substrates. The establishment of fundamental issues of the biotic organisation of this group of fungi, which considers both their specific features and integration into general ecological patterns, forms the necessary basis for their further research, protection, and practical use (in particular, when indicating and monitoring the state of forest biocenoses). The purpose of the study was to establish the species composition, taxonomic structure, and distribution (by mycohorizons) of aphyllophoroid macromycetes of forest stands in Zhytomyr Polissia. In the course of the study, classical phytopathological and forestry-inventory (biometric) analysis methods were used. Special methods of mycology, in particular, mycoindication, were also used in terms of identifying and examining aphyllophoroid macromycetes. Mycoflora of aphyllophoroid macromycetes of forest stands of Zhytomyr Polissia has 27 species belonging to 17 families, 8 orders of the Agaricomycetes class of the Basidiomycota division and is typical for the European temperate zone. The systematic component of the group under study is represented by the following orders: Polyporales (40.7% of their total number), Hymenochaetales (18.5%), Agaricales (14.8%), Russulales (11.2%), Cantharellales, Thelephorales, Auriculariales, and Gomphales (3.7% each). Analysis of the food structure of aphyllophoroid macromycetes shows that most of the mycoflora is represented by a complex of saproxilotrophic species, to a lesser extent parasite fungus (for example, Inonotus hispidus, Phellinus robustus, Heterobasidion annosum) and humus saprotrophs (Thelephora terrestris) are noted. The distribution of macromycetes by mycohorizons identifies that more than 70% of all finds were located in the subsurface mycohorizon, and the root mycohorizon is characterised by the smallest number of finds and species of macromycetes. There is a gradual decrease in the species diversity of aphyllophoroid macromycetes in the forest edge areas, which demonstrates fundamentally different stages of forest ecosystem degradation processes. The investigation of historical relationships between woody plant species and aphyllophoroid macromycetes, which act as biological indicators of the state of forest ecosystems, will further allow forming the of “maps of disruption of the integrity of forest biocenoses” for the analysis of sanitary risks, which should be implemented in the practice of forest protection

Інформаційно-аналітичні матеріали до науково-практичної конференції з питань напрацювання заходів попередження поширення шкідників і хвороб лісу Масове всихання хвойних л іс ів-прогноз невтішний! В Україні, як і в багатьох інших країнах світу, стрімко поширюється масове всихання хвойних лісів, пов'язане зі зміною клімату, зокрема глобальним потеплінням. За підвищеної температури повітря та зменшеної кількості атмосферних опадів знижується рівень ґрунтових вод, що не є сприятливим для дерев, і вони втрачають опір до заселення шкідливими комахами та ураження збудникам хвороб. Якщо раніше патологічні процеси розвивалися переважно у пристигаючих соснових лісах (віком понад 80 років), то нині часто інтенсивно всихають середньовікові насадження і навіть молод няки. Перші осередки усихання соснових лісів були зафіксовані в Україні в 2011 році в Житомирській області. За даними 2015 року межа осередків усихання посунулася в північнозахідному напрямку. Ще через рік соснові насадження практично усіх північно-західних області України вже були пошкоджені. У кінці 2017 року усихання сосни як наслідок атак шкідників було виявлене в центральних областях України. Весняне обстеження 2018 року показало, що ці осередки поширилися також у лісостеповій зоні, зокрема на Лівобережжі. Осередки масового усихання охоплюють Волинську, Житомирську, Київську, Львівську, Рівненську, Хмельницьку, Черкаську, Чернігівську області і продовжують поширюватися. Прогноз дуже невтішний: за декілька десятків років Україна може втратити значну частку соснових насаджень, за останніми даними, площа заселених шкідниками соснових лісів, підпорядкованих Держлісагентству, сягає біля 350 тис. га. Заселення верхівковим короїдом майже завжди спричиняє всихання соснових лісів Всихання дерев сосни відбувається за верхівковим типом-короїд спочатку заселяє товсті гілки та частину стовбура з тонкою корою. Після проникнення жуків під кору, прогризання маточних ходів, відкладання яєць, вилуплення личинок і початку їхнього живлення хвоя заселених дерев починає змінювати колір від зеленого на тьмяно-сіро-зелений, а в кінці-на рудий, гілки відмирають, дерево гине. Одночасно ходами поширюється синява, спричинена дерево-забарвлювальними грибами. Спочатку всихають окремі дерева, далі цілі куртини, а потім всихання охоплює значну частину деревостану. Аналіз загиблих дерев в осередках всихання сосни виявив поселення верхівкового короїда в гілках і верхівках, шестизубчатого короїда-в окоренкових частинах стовбура і чорного соснового вусача на ділянках стовбурів із перехідною корою. Насамперед осередки масового розмноження короїдів виникають в одноярусних одновікових лісові масивах з однією чи двома основними породами, переважно штучного походження. Такі деревостани найменш стійкі до дії різноманітних несприятливих чинників-вітру, ураження грибами, пошкодження комахами, серед яких короїди є найбільш агресивними, оскільки заселяють ледве ослаблені дерева. Здорова сосна виділяє живицю, яка є токсичною для короїдів і навіть просто заливає жуків під час спроб заселення дерева. Водноч...

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.