Current State of Pineries in Zhytomyr Polissia Under the Influence of Environmental Factors

Recently, there has been a massive drying of conifers all over the world. In North America and Siberia, there are millions of hectares of shrunken plantings; in Europe, pines and firs have been drying up over the past two decades. Furthermore, considerable damage is caused to woody plants by phyto-pest and phyto-diseases, since mass reproduction of Ips typographus Linnaeus, Ips acuminatus Gyllenhal has been observed in Europe in recent years, Dendroctonus micans Kud – in North America, Polygraphus proximus Blandford – in East Asia. Nematodes also cause significant damage to pine forests. Among phyto-diseases, Heterobasidion annosum (Fr.) Bref. harmfully affects Pinus sylvestris L. The appearance of foci of shrunken trees in different parts of the globe indicates the global nature of processes associated with cyclical planetary processes and climate change. This study describes climate changes in the research region for 1961-2020. According to the analysis, it was found that for 2009-2020, considerable damage to pine plantations in Zhytomyr Polissia is caused among needle-eating insects – Panolis flammea Denis & Schiffermuller, Diprion pini L., Neodiprion sertifer Geoffroy; among other pests – Aradus cinnamomeus Panz, Dendrolimus pini L., Bupalus piniarius L. The greatest harmful effect that pineries have recently sustained has been caused by Diprion pini L. It was also found out that among phyto-diseases suffered by the pine forests, significant damage has been done by Heterobasidion annosum (Fr.) Bref., with the damaged area of 13.0-14.2 thousand hectares. Hydrothermal analysis was performed for 2009-2020. The influence of solar activity on the number of phyto-pest and diseases is analysed. This paper provides the estimate of the amount of CO2 emissions is given for 2009-2020. It was found that since 2014, the amount of carbon dioxide emissions has decreased from 1.5 million tonnes to 0.6 million tonnes. Correlation analysis of all indicators indicated a high mutual influence between the area of trees damaged by insect pest, root sponge, the Wolf number, and CO2 emissions to the environment. Mathematical dependences are obtained to predict the influence of the W number on damage to pineries by forest pests and diseases in the conditions of Zhytomyr Polissia

Сurrent condition of pine plantations of Kyiv Polisya under the influence of environmental factors

The article describes the climate change in the study region for the period 1968-2020. It was specified that over the past fifty-nine years there has been an increase in average annual air temperature by 2,5°C, a decrease in relative humidity by 6,0% and average annual rainfall by 5 mm. According to the analysis, it was determined that during the period 2009-2020 significant damage to pine plantations of Kyiv Polissya is caused by the pests like common pine sawfly (Diprion pini L.), pine bark beetle (Aradus cinnamomeus Panz), pine silkworm (Dendrolimus pini L.), pine weevil (Leucaspis pusilla Loew), and pine star weaver (Acantholyda nemoralis Matsumura). Heterobasidion annosum (Fr.) Bref. has also caused a significant damage to pine forests over the past eleven years; the damaged area is of ​​12,8-15,9 thousand hectares. According to the hydrothermal analysis of the study area, it was determined that 2009 and 2015 were characterized as years of medium drought; 2010, 2016, 2017, 2020 were the years of low drought; 2011–2014, 2018, 2019 were the years of sufficient moisture supply. The analysis of the number W influence found that in the years of increased solar activity the number of phytopests increases, while in the years of minimal solar activity it decreases. Based on the statistical indicators, the analysis of CO2 emissions into the environment for the period 2009-2020 and it was found that since 2012 the amount of carbon dioxide emissions has decreased from 10,2 million tons to 3.7 million tons. Correlation analysis of all indicators showed the interaction between the area of ​​damaged trees by insect pests and the Wolf number, CO2 emissions into the environment, average annual precipitation amounts and hydrothermal moisture coefficient of Selyaninov G.T. There is also a correlation between the area of ​​damaged plantations by pine fungus and the average annual air temperature, relative humidity and CO2 emissions.

Biotic factors damaging forest stands in Gornata Koria and Chuprene Reserves in Western Balkan Range, Bulgaria

Assessment and monitoring of health status in deteriorated forest stands in Gornata Koria and Chuprene Reserves in Western Balkan Range (Bulgaria) were conducted in 2017. An integrated approach (based on remote sensing technologies and terrestrial validation) was applied. A series of subsequent terrain observations were carried out in both protected areas mainly in dead or in poor health status stands. As a result, sixteen insect species were identified in Gornata Koria and nine pests in Chuprene Reserves. The predominant number of pests included bark beetles and weevils (Curculionidae), longhorn beetles (Cerambycidae), etc. Attacks caused by the European bark beetle (Ips typographus) formed the main disturbance in the Norway spruce forests in both reserves. Ten parasitic and ten saprophytic fungi were identified in the stands of the Norway spruce (Picea abies), silver fir (Abies alba) and European beech (Fagus sylvatica). Among the parasitic fungi, six species were identified as destructive (Armillaria sp., Heterobasidion annosum, Fomitopsis pinicola, Fomes fomentarius, Ramaria flava and Pholiota squarrosa).

Comparative Efficacy of State-of-the-Art and New Biological Stump Treatments in Forests Infested by the Native and the Alien Invasive Heterobasidion Species Present in Europe

The Heterobasidion annosum species complex includes major fungal pathogens of conifers worldwide. State-of-the-art preventative stump treatments with urea or with commercial formulations of the fungal biological control agent Phlebiopsis gigantea (i.e., Rotstop®) may become no longer available or are not approved for use in many areas of Europe infested by the three native Heterobasidion species and by the North American invasive H. irregulare, making the development of new treatments timely. The efficacy of Proradix® (based on Pseudomonas protegens strain DSMZ 13134), the cell-free filtrate (CFF) of the same bacterium, a strain of P. gigantea (MUT 6212) collected in the invasion area of H. irregulare in Italy, Rotstop®, and urea was comparatively investigated on a total of 542 stumps of Abies alba, Picea abies, Pinus pinea, and P. sylvestris in forest stands infested by the host-associated Heterobasidion species. Additionally, 139 logs of P. pinea were also treated. Results support the good performances of Rotstop®, and especially of urea against the native Heterobasidion species on stumps of their preferential hosts and, for the first time, towards the invasive North American H. irregulare on stumps of P. pinea. In some experiments, the effectiveness of Proradix® and of the strain of P. gigantea was weak, whereas the CFF of P. protegens strain DSMZ 13134 performed as a valid alternative to urea and Rotstop®. The mechanism of action of this treatment hinges on antibiosis; therefore, further improvements could be possible by identifying the active molecules and/or by optimizing their production. Generally, the performance of the tested treatments is not correlated with the stump size.

High Seedling Mortality of Scots Pine Caused by Heterobasidion annosum s.s.

This study provides new information on the infection biology and pathogenicity of an important root-rot fungus, Heterobasidion annosum sensu stricto (Fr.) Bref., through a detailed examination of the vegetative spread of clonal individuals and their capacity to produce fruiting bodies on young pine seedlings. The seedlings were planted in a clear-cutting area (c. 1.2 ha in size) after a pine generation that showed slight external symptoms of Heterobasidion root rot. The first dead seedlings were found five years after planting and during a nine-year monitoring period; nearly 600 seedlings were killed by H. annosum s.s. in 48 individual disease centers. Based on pairing tests of 482 isolates, 117 different H. annosum s.s. genotypes were identified. On average, 2.9 genotypes occurred in a single disease center. The extensive secondary spread of genotypes within root systems (up to 48 pine seedlings infected by the same genotype) resulted in annually expanding disease centers. In addition, more than half of the seedlings killed by H. annosum s.s. produced perennial fruiting bodies thus providing air-borne inoculum. The risk of spore infection should be taken into account in any type of cutting operation in young pine stands. Moreover, new control measures directed towards the secondary spread of H. annosum s.s. in pine regeneration are urgently needed in order to maintain the productivity of the pine forest on infested sites.

Effect of root and butt rot uncertainty on optimal harvest schedules and expected incomes at the stand level

• Key message Root and rot (RBR) caused byHeterobasidion parviporumNiemelä & Korhonen andHeterobasidion annosum(Fr.) Bref. damages Fennoscandian spruce stands. In case the rot infection and its severity are unknown, the mere risk of infection should seldom affect the harvest timing. When it does, the gains by harvesting earlier are minimal. • Context It has been suggested that stands infected by RBR should be harvested earlier than the healthy ones. Yet, we must decide on harvest timing decisions without reliable information on the infection. • Aims We studied if harvesting earlier pays off under RBR uncertainty. • Methods We structured the uncertainty with a decision tree and calculated the optimal rotations based on expected net present values. We compared rotation lengths to those of healthy stands and calculated gains from earlier harvesting. • Results The inclusion of RBR-related uncertainty in the model changed the rotation length of only 14–23% of the stands. The average reduction was 1.3–4.7 years. Yet, the gain from harvesting earlier was too low to be considered. • Conclusion In the absence of information on the extent and severity of RBR, it seldom pays off to advance harvests. The value growth in healthy trees tends to compensate for the value reduction due to rot.

Inferences on the Susceptibility of Wood of Different Tree Species to Heterobasidion annosum Sensu Lato (Fr.) Bref. Primary Infections and on the Range of Pathogen Spores Dispersal

Stumps play a pivotal role in the epidemiology of the fungal forest pathogens Heterobasidion spp. because they are the main courts of primary airborne infections. The aims of this study were (i) to determine the susceptibility of seven tree species (i.e., Larix sibirica, Picea abies, Picea sitchensis, Pinus contorta, Pinus strobus, Pinus sylvestris and Pseudotsuga menziesii) to primary infection by H. annosum and H. parviporum through comparative inoculation experiments of conidia on wood discs in controlled conditions; (ii) to compare the susceptibility of wood discs of the same tree species to natural airborne infections in two Latvian Norway spruce forest stands infested either by H. annosum or H. parviporum; (iii) to explore the rates of infection of wood discs at increasing distances from spore sources in these two forests to make inferences on the range of spores dispersal. Results obtained by spraying wood discs with conidial suspensions in controlled conditions are in agreement with those obtained by exposing wood discs to the natural airborne inoculum in the forests, as clearly supported by the significant correlation (r = 0.79; p < 0.05) between the two sets of data. Susceptibility was highest in Pinus species, followed by P. abies and P. sitchensis. Susceptibility was lowest for L. sibirica and P. menziesii. The area colonized by Heterobasidion spp. in the sapwood of wood discs was much greater than that colonized in the heartwood. A sharp decrease in the rate of infection of wood discs with distance from spore sources (i.e., fruiting bodies) was observed, further confirming the importance of local spore sources in the epidemiology of Heterobasidion spp. Taken together, these findings could help designing tactics to manage these fungal forest pathogens.

Induction of Defense Responses in Pinus sylvestris Seedlings by Methyl Jasmonate and Response to Heterobasidion annosum and Lophodermium seditiosum Inoculation

The induction of defense responses in Pinus sylvestris L. seedlings by methyl jasmonate (MeJA) was investigated in three experiments. Two different MeJA application methods were tested, and induction of defense responses was assayed by seedling inoculation with Heterobasidion annosum (Fr.) Bref. and Lophodermium seditiosum Minter, Staley and Millar. In the first experiment, five-year-old P. sylvestris ramets of one clone were directly treated with MeJA, followed by inoculation with H. annosum. In the second experiment, open-pollinated Scots pine seedlings were treated with MeJA by direct spraying and vaporization, and inoculation with H. annosum was done using a slightly modified protocol. In the third experiment, open-pollinated Scots pine seedlings were treated with MeJA by vaporization and inoculated with L. seditiosum. Direct application of MeJA induced seedling mortality, and in some cases, decreased resistance to inoculation with H. annosum. Application of MeJA by vaporization was less stressful for seedlings, and resulted in increased resistance to both H. annosum and L. seditiosum. In addition, an unforeseen Neodiprion sertifer (Geoffroy) and Hylobius abietis L. infestation provided anecdotal evidence of the efficacy of MeJA in inducing resistance to insect pests as well. Further studies are required on the induction of resistance to additional diseases and pests. Induced resistance could be used as a possible protective mechanism for Scots pine seedlings prior to planting during reforestation of stands to increase vitality and survival.

Особливості сортовипробування сосни звичайної на стійкість до кореневої губки у лісостеповій частині Харківської області

Висвітлено результати обстеження потомств клонових насінних плантацій (КНП) сосни звичайної – кандидатів у сорти-популяції синтетичні та їхніх регіональних контрольних варіантів (Харківська, Київська, Волинська області), які випробовують у ДП «Гутянське ЛГ» Харківської області. У всіх варіантах визначено таксаційні показники дерев, селекційну категорію, стан та особливості радіального приросту. Проаналізовано особливості накопичення шарів пізньої та ранньої деревини та визначено їхні частки у радіальному прирості. Як критерій, що характеризує стійкість дерев до кореневої губки, запропоновано використати частку пізньої деревини в радіальному прирості. Перспективність використання насіння з КНП, потомства яких випробовують на ділянці, у локальних умовах вирощування, оцінювали за висотою, діаметром, селекційною категорією, станом і часткою пізньої деревини у річному прирості. Перспективними для вирощування у Лісостеповій частині Харківської області виявилися кандидати у сорти-популяції ‘Київський-3’, ‘Прихилківський-1’, ‘Прихилківський-2’. Ефективність використання частки пізньої деревини як маркерної ознаки стійкості потребує подальшого підтвердження. Ключові слова: Pinus sylvestrys L., Heterobasidion annosum s. l., кандидати у сорти-популяції, селекційні ознаки, комплексне оцінювання, радіальний приріст, потомства КНП.