Pine Species Research Articles

Involvement of Lophodermella sulcigena in Endemic Disease of Pinus mugo Needles in the Polish Tatra Mountains

Pinus mugo plays a significant ecological role in the natural environment at high altitudes in the mountains including the Alps, Pyrenees, Carpathians, and Balkans. In such severe conditions, it is subjected to the harmful effects of various abiotic and biotic factors. In one of the areas of its natural occurrence in Tatra Mts. (southern Poland), for the last few years, a significant intensification of needle disease has been observed. Symptoms similar to those recorded in Tatra Mts. also occur on other Pinus species in Europe and North America, where they are caused by fungi belonging to the genus Elytroderma, Lophodermella, Lophophacidium or Ploioderma (Rhytismataceae). The current paper presents the results of research which was mainly aimed at characterization of disease symptoms observed for the first time in Poland on P. mugo needles, and identification of the main causal agent with use of the morphological and molecular technique. Based on the analyses performed at different times of the year (2015–2020), it was found that dieback symptoms initially appeared only on first-year needles, a few weeks after their development. Symptoms occur on one or both needles in the bundle. The distal parts of the needles died, while the basal parts remained green. In the following year, mainly in June and July, on the previous year’s needles attached to the shoots, mature ascomata can be seen. The fungus Lophodermella sulcigena has been identified as the cause of these symptoms. So far, the related species L. conjuncta has not been found. The morphological features of the pathogen microstructure produced on P. mugo needles are presented. Attention was drawn to certain features that may make its identification difficult, especially in terms of shapes and sizes of ascospores. The phylogenetic position of the identified causal agent in relation to closely related other species was determined. The current results confirmed that L. sulcigena shows great phylogenetic similarity to L. montivaga, which is found in North America. Nine rDNA barcode sequences of L. sulcigena obtained in this work will enrich the NCBI GenBank database. The obtained results, indicating the presence of other fungi in L. sulcigena ascomata, which may limit the spread of its ascospores, were also discussed.

Shifts from an extensive to an intensive root nutrient‐acquisition mode with stand development of three Pinus species

Abstract Plant roots employ diverse strategies to acquire soil nutrients, including direct nutrient uptake through absorptive fine roots and root hairs, scavenging nutrients by forming symbioses with mycorrhizal fungi, and mining nutrients by releasing root exudates. However, whether these three strategies are differently coordinated among phylogenetically closely related tree species and how this coordination shifts with stand development remains largely unclear. To fill these knowledge gaps, we measured 13 root morphological, architectural, physiological and mycorrhizal traits tightly related to nutrient‐acquisition of three Pinus species (P. sylvestris var. mongolica, P. densiflora and P. tabuliformis) at young (20‐year‐old) and mature (50‐year‐old) stages planted in nutrient‐impoverished sandy soils, in Northeast China. We found that young trees had thinner absorptive fine roots and a higher specific root length than mature trees across three Pinus species, indicating that roots become morphologically less efficient in ‘do it yourself’ scavenging nutrients during stand development. Moreover, young stands had greater root length density and root area index, and mature stands had faster root‐exudation rates, suggesting that young stands rely more on expanding soil volumes to scavenge nutrients and mature stands depend more on root exudation to ‘mine’ nutrients. The three Pinus species exhibited different nutrient‐acquisition strategies at the mature stage; P. densiflora had higher root length density and root area index, and the other two Pinus species had greater ectomycorrhizal colonization rates. Synthesis. Our findings highlight that phylogenetically closely related tree species may exhibit different nutrient‐acquisition strategies and suggest a shift from an extensive nutrient‐acquisition mode depending more on absorptive fine roots to an intensive nutrient‐acquisition mode relying more on root exudation during stand development.

An Overview of Mycorrhiza in Pines: Research, Species, and Applications.

In the latest literature, climate models show that the conditions for pines, spruces, larches, and birches will deteriorate significantly. In Poland, as well as in other European countries, there are already signs of the decline of these species. This review article deals with the symbiotic relationships between fungi and plants, which can hardly be overestimated, using the example of pine trees. These are the oldest known symbiotic relationships, which are of great benefit to both components and can help plants, in particular, survive periods of severe drought and the attack of pathogens on the roots. This article describes symbioses and their causal conditions, as well as the mycorrhizal components of pine trees and their properties; characterizes ectomycorrhizal fungi and their mushroom-forming properties; and provides examples of the cultivation of pure fungal cultures, with particular attention to the specificity of the mycorrhizal structure and its effects on the growth and development of Pinus species. Finally, the role of mycorrhiza in plant protection and pathogen control is described.

The first report of dark septate endophytes from Indonesian Pinus merkusii and its symbiosis role as a plant growth promoter in nursery condition

Abstract. Akhir J, Herliyana EN, Surono, Budi SW. 2024. The first report of dark septate endophytes from Indonesian Pinus merkusii and its symbiosis role as a plant growth promoter in nursery condition. Biodiversitas 25: 312-321. To encourage the healthy growth of Pinus merkusii Jungh et de Vriese seedlings at the seedling stage, Dark Septate Endophytic (DSE) fungi were used as growth promoters. In this study, four DSE strains, i.e., Apls 1.5.3, Pls 32.1, Hs14.6a, and Hs14.6c isolated from P. merkusii roots, were tested for their ability to stimulate the growth of P. merkusii seedlings. After 14 weeks of incubation in nursery conditions, P. merkusii seedlings inoculated with four DSE strains experienced a higher increase in height and stem diameter when compared to the control treatment. Overall, the biomass results of P. merkusii seedlings treated with the DSE strains performed better than those of the control. Root colonization of P. merkusii seedlings showed that the 4 DSE strains significantly outperformed the control. The Hs14.6c strain outperformed the other strains and controls regarding nutrient (nitrogen) uptake. The findings of this study are the first to show that the DSE Apls 1.5.3 strain is similar to Cylindroccarpon, the Hs14.6a and Hs14.6c strains are similar to Cladophialophora sp., and the Pls 32.1 strain is similar to Oncopodiella trigonella based on identification results and phylogenetic trees and can be in symbiosis with seeds of P. merkusii, a pine species native to Indonesia.

Assessing the potential impact of retaining native off‐site tree species in woodland restoration

Reestablishing appropriate tree species is an important step in converting off‐site monocultures into woodlands. Species conversion is often necessary, as off‐site exotic species rarely function like woodland species. However, when off‐site tree species are native, and functionally redundant to woodland species, conversion may be unnecessary. To explore this possibility in the southeastern United States, we reviewed the literature on trait differences among the primary southern pines and qualitatively assessed the effect of their identity at the species and stand‐levels. In this region, woodland restoration focuses on removing loblolly (Pinus taeda) and slash pine (P. elliottii) to reestablish longleaf (P. palustris) or shortleaf pine (P. echinata). Our review found minimal variation among species in understory flammability, fire resistance at maturity, and Red‐cockaded Woodpecker (Leuconotopicus borealis) habitat at the stand‐level. Longleaf and shortleaf pine were generally more resistant to abiotic and pest disturbance at the tree‐level; however, stand‐level differences in wind, drought, and boring insect resistance among southern pines growing in open forests were considered minimal. Retaining loblolly and slash pine will improve stand‐level productivity in the short term, but creates regeneration problems due to low juvenile fire resistance and resilience. Ice resistance and long‐term carbon sequestration will also likely be reduced by retaining loblolly and slash pine. Collectively, these results suggest that southern pine species are generally interchangeable at the stand‐level in woodlands; although woodlands featuring loblolly and slash pine may be less stable in the face of disturbance than those dominated by shortleaf and longleaf pine.

Differences and similarities in radial growth of Betula species to climate change

Betula platyphylla and Betula costata are important species in mixed broadleaved-Korean pine (Pinus koraiensis) forests. However, the specific ways in which their growth is affected by warm temperatures and drought remain unclear. To address this issue, 60 and 62 tree-ring cores of B. platyphylla and B. costata were collected in Yichun, China. Using dendrochronological methods, the response and adaptation of these species to climate change were examined. A “hysteresis effect” was found in the rings of both species, linked to May–September moisture conditions of the previous year. Radial growth of B. costata was positively correlated with the standardized precipitation-evapotranspiration index (SPEI), the precipitation from September to October of the previous year, and the relative humidity in October of the previous year. Growth of B. costata is primarily restricted by moisture conditions from September to October. In contrast, B. platyphylla growth is mainly limited by minimum temperatures in May–June of both the previous and current years. After droughts, B. platyphylla had a faster recovery rate compared to B. costata. In the context of rising temperatures since 1980, the correlation between B. platyphylla growth and monthly SPEI became positive and strengthened over time, while the growth of B. costata showed no conspicuous change. Our findings suggest that the growth of B. platyphylla is already affected by warming temperatures, whereas B. costata may become limited if warming continues or intensifies. Climate change could disrupt the succession of these species, possibly accelerating the succession of pioneer species. The results of this research are of great significance for understanding how the growth changes of birch species under warming and drying conditions, and contribute to understanding the structural adaptation of mixed broadleaved-Korean pine (Pinus koraiensis) forests under climate change.

Ulcerative tumour-like disease of white fir in the Pokuttia Carpathians

The current state of dark coniferous forests on Earth is a bio-indicator of global environmental change, in particular, the process of gradual degradation of tree species of the genera Pine, Spruce and Fir, due to the negative impact of anthropogenic activities, abiotic and biotic factors. The purpose of the study is to establish the symptoms, prevalence and harmfulness of the causative agent of ulcerative tumour-like disease on the shoots and trunks of white fir. The research was conducted on the territory of the forest fund of the Pokuttia Carpathians, in particular, within the branch Kutske forestry of the State Specialised Economic Enterprise “Forests of Ukraine” in the Kosivske forest enterprise. The study uses classical phytopathological and mycological methods, which are used to investigate the aetiology of the disease, analyse typical symptoms (starting from the early stages), and perform microscopy of the affected parts of fir. The symptoms, aetiology, and pathogenesis of white fir ulcer-like disease, which tends to spread, were investigated. A new name for the disease is substantiated, in particular, it is proposed to use the name “ulcerative tumour-like disease” of fir instead of the current name “cancer”. It is shown that a typical sign of infection is the development of tumours, which eventually transform into ulcers. It was found that the tumour-like type of lesion prevails on the undergrowth of fir, and on plants of the upper tiers – ulcerative. It is noted that a typical sign of ulcerative tumour-like disease of white fir is also the presence of pathologies such as “witches’ broom”. It is proposed to remove affected trees with typical signs of infection with ulcerative tumour-like disease to reduce the infectious background, especially during lighting and cleaning, since affected trees are not released from infection. Therefore, assessing the risk of infection of white fir trees with ulcerative tumour-like disease at the level of specific stands and ensuring an appropriate response to potential infection risks is an important part of sustainable forest management

Evaluating immaturity risk in young stands of the serotinous knobcone pine (Pinus attenuata)

AbstractAs wildfire becomes increasingly frequent, many serotinous plant populations risk local extirpation if fire recurs prior to sufficient seed accumulation in the canopy (i.e., “immaturity risk”). Following two 2018 wildfires in northwestern California, we studied seed viability, cone production, and postfire regeneration of a serotinous conifer, knobcone pine (Pinus attenuata), with stand ages (time since fire) ranging from 6 to 79 years. Cone density per tree was more strongly associated with tree diameter than age, and cone density was positively related to postfire seedling regeneration. Most of the postfire knobcone pine regeneration established during the first year with high survivorship in the following first postfire year. Adjusting for survivorship, the estimated minimum age for knobcone pine to promote self‐replacement (one recruit per tree) was 9.5 years (or 4.6‐cm dbh) and the probability of reburning at the modern fire rotation of 43 years was 19.8%. Based on our results, we found that immaturity risk was currently low for knobcone pine. Our approach provides a quantitative method to assess immaturity risk in knobcone pine and other serotinous conifer species that can be used to evaluate future risk under rapidly changing climate and fire conditions.

Height increment patterns in Pinus pinaster seedlings emerging in naturally regenerated gaps

Abstract The group selection cutting system provides a promising technique for transforming monospecific even-aged stands into uneven-aged, mixed stands. However, this system has scarcely been used to regenerate Mediterranean shade-intolerant species. In this study, we analyze the height increment patterns of Pinus pinaster seedlings emerging in naturally regenerated gaps. P. pinaster is a shade-intolerant pine species distributed throughout the Mediterranean basin. An experimental trial was established in a 50-year-old P. pinaster (maritime pine) plantation located in the mountains of central Spain. Gaps of two different sizes (diameter equal to 1.5 and 2.5 times the dominant height of the stand, 26 and 44 m, respectively) were opened during winter 2017–18. A total of 531 subplots with a 1-m radius were installed in spring 2018, distributed within the gaps as well as in control plots adjacent to the gaps. Seedlings were tagged individually and variables including height, along with other ecological variables, were collected twice a year (in spring and autumn), providing six time intervals for the development of our models. We applied seemingly unrelated regression to analyze the height growth in this polycyclic species, allowing us to model spring and autumn height increments at the same time. Our results showed that seedling height growth depended on the silvicultural treatment, meteorological conditions during the spring growth season, inter-specific scrub competition, position within the gap, and seedling characteristics, such as the ontogenetic development or the size of the seedling itself. This work, along with germination and survival analysis, aims to provide a holistic perspective on the suitability of the group selection cutting system to regenerate maritime pine stands, taking into account current and future climate change scenarios.

Demographic dynamics and molecular evolution of the rare and endangered subsect. Gerardianae of Pinus: insights from chloroplast genomes and mitochondrial DNA markers.

The divergence of subsect. Gerardianae was likely triggered by the uplift of the Qinghai-Tibetan Plateau and adjacent mountains. Pinus bungeana might have probably experienced expansion since Last Interglacial period. Historical geological and climatic oscillations have profoundly affected patterns of nucleotide variability, evolutionary history, and species divergence in numerous plants of the Northern Hemisphere. However, how long-lived conifers responded to geological and climatic fluctuations in East Asia remain poorly understood. Here, based on paternally inherited chloroplast genomes and maternally inherited mitochondrial DNA markers, we investigated the population demographic history and molecular evolution of subsect. Gerardianae (only including three species, Pinus bungeana, P. gerardiana, and P. squamata) of Pinus. A low level of nucleotide diversity was found in P. bungeana (π was 0.00016 in chloroplast DNA sequences, and 0.00304 in mitochondrial DNAs). The haplotype-based phylogenetic topology and unimodal distributions of demographic analysis suggested that P. bungeana probably originated in the southern Qinling Mountains and experienced rapid population expansion since Last Interglacial period. Phylogenetic analysis revealed that P. gerardiana and P. squamata had closer genetic relationship. The species divergence of subsect. Gerardianae occurred about 27.18 million years ago (Mya) during the middle to late Oligocene, which was significantly associated with the uplift of the Qinghai-Tibetan Plateau and adjacent mountains from the Eocene to the mid-Pliocene. The molecular evolutionary analysis showed that two chloroplast genes (psaI and ycf1) were under positive selection, the genetic lineages of P. bungeana exhibited higher transition and nonsynonymous mutations, which were involved with the strongly environmental adaptation. These findings shed light on the population evolutionary history of white pine species and provide striking insights for comprehension of their species divergence and molecular evolution.

Year-long evaluation of total soluble proteins in the trunk of two pine species from northeastern Mexico

Objective: To quantify the one-year total soluble protein (TSP) concentration in the trunk of two pine species.
 Design/Methodology/Approach: The Bradford method (1976) was used to determine the TSP concentration in the two pine species. Statistical tests were subsequently performed with the IBM SPSS 18 Software, using a general linear model (GLM) univariate analysis.
 Results: The TSP concentration was different for each month. The highest concentration was recorded in August (6.84 mg gMS-1 for Pinus pinceana Gordon and 6.82 mg gMS-1 for Pinus cembroides Zucc), and the lowest was registered in April (5.53 mg gMS-1 for Pinus cembroides Zucc) and February (6.64 mg gMS-1 for Pinus pincenana Gordon).
 Study Limitations/implications: There is a lack of information regarding these two pine species and scarce studies explain the behavior of the TSP.
 Conclusions: The concentration of total soluble proteins varies in each month of the year. Further studies that include more plant organs are required to obtain a broader protein profile for both species.

Evidence that Ophiostomatoid Fungal Symbionts of Mountain Pine Beetle Do Not Play a Role in Overcoming Lodgepole Pine Defenses During Mass Attack.

Mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) is a devastating forest insect pest that has killed millions of hectares of pines in western North America over the past two decades. Like other bark beetles, MPB vectors ophiostomatoid fungal species, some of which are pathogenic to host pine species. The phytopathogenicity of these fungal symbionts has sparked considerable debate regarding their role in facilitating MPB attack success. We tested the hypothesis that MPB ophiostomatoid fungal associates like Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield contribute to overwhelming host defenses during MPB mass attack. We compared responses of mature lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) trees growing in natural stands that were mass attacked by MPB with those inoculated with G. clavigera by examining host defense hormones, secondary metabolites, and gene expression profiles. The jasmonate and ethylene signatures of necrotrophic pathogen-triggered response were identified in G. clavigera-inoculated trees, but only the jasmonate signature of a herbivore-triggered response was measured in MPB-attacked trees. Several G. clavigera-induced changes in pine phenolic metabolite profiles and phenolic biosynthesis gene expression patterns were absent in MPB-attacked pines. These findings indicate that ophiostomatoid fungi like G. clavigera are not a major factor in overwhelming host defenses during MPB mass attack. Instead, fungal pathogenicity likely is more important in aiding MPB colonization and development within the host tree. Phenolics appear to play a larger role in the host response to G. clavigera than to MPB, although phenolics may also influence MPB feeding and behavior. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Urban Dominant Trees Followed the Optimal Partitioning Theory and Increased Root Biomass Allocation and Nutrient Uptake under Elevated Nitrogen Deposition

Nitrogen (N) is one of the limiting nutrients for plant growth and metabolism in terrestrial ecosystems. Numerous studies have explored the effects of N addition on the eco-physiological traits and biomass production of plants, but the underlying mechanism of how N deposition influences biomass allocation patterns remains controversial, especially for urban greening trees. A greenhouse experiment was conducted for 7 months, using two dominant tree species of urban streets in North China, including the coniferous tree species Pinus tabuliformis and the broadleaved tree Fraxinus chinensis, under three levels of N addition: ambient, low N addition, and high N addition (0, 3.5, and 10.5 gN m−2 year−1). The plant growth, biomass distribution, functional traits, and soil nutrient properties of the two trees were determined. Overall, N addition had positive effects on the aboveground and belowground biomass of P. tabuliformis, which also shifted its functional traits to an acquisitive strategy, while F. chinensis only increased root biomass distribution and fast traits as N increased. Furthermore, N supply increased the soil N and phosphorus availability of both trees and improved their root nutrient uptake capacity, resulting in an increase in their root–shoot ratio. Optimal partitioning theory could better explain why trees would invest more resources in roots, changing root structure and nutrient uptake, thus increasing root biomass allocation to adapt to a resource-poor environment. These findings highlight the importance of plant functional traits in driving the responses of biomass allocation to environmental changes for urban greening dominant tree species and could help to come up with new tree growth strategies in silvicultural practice for urban green space.

Physiological, metabolic and hormonal responses of two Pinus spp. with contrasting susceptibility to brown-spot needle blight disease.

Needle blights are serious fungal diseases affecting European natural and planted pine forests. Brown-spot needle blight (BSNB) disease, caused by the fungus Lecanosticta acicola, causes canopy defoliation and severe productivity losses, with consequences depending on host susceptibility. To gain new insights into BSNB plant-pathogen interactions, constitutive and pathogen-induced traits were assessed in two host species with differential disease susceptibility. Six-month-old Pinus radiata D. Don (susceptible) and Pinus pinea L. (more resistant) seedlings were needle inoculated with L. acicola under controlled conditions. Eighty days after inoculation, healthy-looking needles from symptomatic plants were assessed for physiological parameters and sampled for biochemical analysis. Disease progression, plant growth, leaf gas-exchanges and biochemical parameters were complemented with hormonal and untargeted primary metabolism analysis and integrated for a holistic analysis. Constitutive differences between pine species were observed. Pinus pinea presented higher stomatal conductance and transpiration rate and higher amino and organic acids, abscisic acid as well as putrescine content than P. radiata. Symptoms from BSNB disease were observed in 54.54% of P. radiata and 45.45% of P. pinea seedlings, being more pronounced and generalized in P. radiata. For both species, plant height, sub-stomatal CO2 concentration and water-use efficiency were impacted by infection. In P. radiata, total soluble sugars, starch and total flavonoids content increased after infection. No differences in hormone content after infection were observed. However, secondary metabolism was induced in P. pinea visible through total phenolics, flavonoids and putrescine accumulation. Overall, the observed results suggest that P. pinea constitutive and induced traits may function as two layers of a defence strategy which contributed to an increased BSNB resistance in comparison with P. radiata. This is the first integrative study linking plant physiological and molecular traits in Pinus-Lecanosticta acicola pathosystem, contributing to a better understanding of the underlying resistance mechanisms to BSNB disease in pines.

Stochastic processes and changes in evolutionary rate are associated with diversification in a lineage of tropical hard pines (Pinus)

The study of the patterns of polymorphism and molecular evolution among closely related species is key to understanding the evolutionary forces involved in the diversification of lineages. This point is a big challenge in species with slow evolutionary rates, long life cycles, and ancient, shared polymorphisms such as conifers. Under the premise of divergence in a stepwise migration process, we expect clinal geographical patterns of purifying selection efficiency, and genetic structure related to latitude or longitude. If migration is accompanied by changes in the environment, we could further expect a role of positive selection in driving species divergence. Here, we infer patterns of polymorphism, efficiency of purifying selection, and molecular evolution using a dataset of 161 nuclear genes (∼71 Kb) in a lineage of hard pines from North America, the Caribbean, Mexico, and Central America presumed to have migrated from North America toward lower latitudes with tropical conditions. Under the premise of differences in selective pressures, we also look for possible signals of positive selection. To test our hypothesis, first we estimated different indices to infer patterns of polymorphism and efficiency of purifying selection (Ka, Ks, Ka/Ks, dN, dS, dN/dS, and dxy) and compared these metrics across five clades. Also, we investigated possible clinal patterns in these indices and morphological traits (needle length and cone length). Then we inferred genetic structure and environmental differences among species to test for possible signals of positive selection using phylogenetic methods in specific clades. We found differences among clades using Ka, Ks, and Ka/Ks with a relaxation of purifying selection, especially in the Elliotti and Patula clades. We also found environmental differences related to geographic distance, and among clades suggesting differences in selective pressures. The indices Ks, dxy, and needle length had relationships with geography but not ovulate cone length. Finally, we found that most analyzed genes are under purifying selection, but there was an exception of faster evolutionary rate in some pine species, suggesting the possible action of positive selection in divergence. Our study indicated that stochastic processes have played a key role in the diversification of the group, with a possible input of positive selection in pines from Mexico and Central America.

Threats to the persistence of sugar pine (Pinus lambertiana) in the western USA

This study assesses how numerous stressors shape the vital rates (survival, growth, and fecundity) of sugar pine across the vast majority of its range. Sugar pine (Pinus lambertiana Dougl.) is the largest Pinus species, an important timber species, and a component of several dry conifer forest types of western North America, in particular the extensive Sierra Nevada mixed conifer forest. The species faces several challenges in the Anthropocene, including a disrupted fire regime, an invasive pathogen, forest structure changes, and drought with ensuing bark beetle epidemics. Managers are concerned about the conservation outlook for sugar pine, but it is unclear where and how to best invest conservation resources. Using data from the US Forest Service’s Forest Inventory and Analysis program, we estimate the parameters for the vital rate functions and use these to construct an integral projection model which predicts the effects of various stressors on the asymptotic population growth rate. The asymptotic population growth rate is near or slightly below one even under reference conditions, and the actual abundance (in terms of both stem density and basal area) slightly declined over the duration of the study (2001–2019). The analysis reveals that wildfire, white pine blister rust, and forest density are key drivers of the demographic rates of sugar pine across its range. Drought and site dryness had lesser, but still meaningful, effects. Fire has strong negative effects on survival, resulting in a strongly negative population trajectory on burned sites. Conversely, lower than average forest density (plot-level basal area) results in a positive population growth rate via beneficial effects on individual growth. These results highlight the value of fire hazard mitigation, particularly where it also reduces forest density, in the conservation of this important species.

Качество семян и пыльцы 7 видов сосны в условиях интродукции в Приморском крае

The purpose of the study is to study the features of generative development of introduced pine species based on the material of the arboretum of the Mountain Taiga Station. The results of studying the morphology and quality of pollen and seeds of pine species under the conditions of the introduction of Primorsky Krai are presented. Pollen and seed viability indicators are the most important characteristics of the development of male generative structures. This, in turn, determines the degree of adaptation of the species to external conditions during introduction. Morphometric indicators of pollen (length and height of the body and air sacs) were determined on micro preparations, and the number of abnormal pollen grains was counted. Pollen viability was determined by germinating it in a 15% sucrose solution in a thermostat at a temperature of 25 ºС using the “hanging drop” method. Under the conditions of introduction, a direct correlation was found between the number of germinated pollen grains and the intensity of growth of pollen tubes. Germination and seed germination energy were determined according to GOST 13056.6‑75. Germination was carried out in Petri dishes on filter paperi n a thermostat at a constant temperature of +24°C. A direct relationship was found between the number of germinated pollen grains and the rate of growth of pollen tubes. Among the studied pine species, P. banksiana, P. hamata, and especially P. sylvestris, have a sufficiently large potential for a favorable completion of the embryonic stage in the generative process. The same species have the best indicators of germination and seed germination energy. The degree of viability of pollen has a direct impact on the formation of full-grained seeds.

Study of the resistance of economically important pine species to dangerous pests on the Absheron Peninsula

The main goal of the research is to study the resistance of widely used pine species in the landscaping of the Absheron Peninsula to serious dangerous pests, to select relatively resistant species, and to recommend them for landscaping farms. At the initial stage of scientific research, phytosanitary monitoring of various types of pine trees cultivated on the peninsula was carried out, dangerous organisms were studied, analyzed, and identified (2020-2023). As a result of the research, it was established that dangerous microorganisms that are often found in economically important pine species in the studied region: pine bark beetle, sub-bark pine bug, pine scale insect, and the causative agent of tar cancer, cause serious damage to the lifestyle and productivity of plants. This is explained by the fact that harmful organisms cannot cause serious harm to the plant due to the activation of protective and regenerative processes inside the plants. Thus, taking into account the resistance of P. eldarica to other unfavourable soil and climatic factors of the peninsula, including the mentioned dangerous pathogenic and harmful insects, in comparison with other species, it is advisable to widely use it as the dominant species in the region’s landscaping.

Flow resin production and its economy by some pine species

Çam ağaçlarından elde edilen reçine ve türevlerine duyulan ihtiyaç gittikçe artmaktadır. Bu çalışmayla ülkemizde yetişen ve reçine üretimine konu olan üç çam türü; Karaçam, Kızılçam ve Fıstıkçamında reçine veriminin ve ekonomisinin değerlendirilmesi amaçlanmıştır. Çalışma Balıkesir Orman Bölge Müdürlüğü, Edremit Orman İşletme Müdürlüğü sınırları içinde yapılmıştır. Her bir ağaç türünden, göğüs çapı 26 cm’den daha büyük olan 52 ağacı kapsayan toplam üç deneme alanında çalışılmıştır. Asit pasta yöntemi kullanılarak, ağaçlarda 5 cm yüksekliğinde ve 30 cm genişliğinde açılan pencerelerden akan reçine bir torbada toplanarak ayrı ayrı tartılmıştır. Elde edilen bulgulara göre ağaç başına, Karaçamda toplam 968-1,452 g aralığında (ortalama 1,285 g), Kızılçamda 859–1,296 g aralığında (ortalama 1,040 g) ve Fıstıkçamında da 998–1,331 g aralığında (ortalama 1,168 g) akma reçine üretilmiştir. Yapılan varyans analizi sonucunda ağaç türlerine göre ağaç başına üretilen akma reçine miktarları arasında istatistiksel olarak anlamlı farklılığın ortaya çıktığı gözlenmiş, çoklu karşılaştırmalar sonucunda da türlerin reçine verimi bakımından Karaçam>Fıstıkçamı>Kızılçam şeklinde sıralandığı görülmüştür. Ayrıca ağaçlardan elde edilen reçine miktarı ile göğüs çapı arasında Karaçam ve Kızılçamda zayıf, Fıstıkçamında ise orta kuvvette ve pozitif yönde bir ilişkinin olduğu saptanmıştır. Yapılan gelir-maliyet analizleri sonucunda ise, 2021 yılı fiyatlarına göre Karaçam, Fıstıkçamı ve Kızılçam için ağaç başına üretilen ürün değeri sırası ile 29,58, 26,86 ve 23,92 ₺ bulunmuşken ağaç başına üretim maliyeti her üç ağaç türü için aynı ve 32,22 ₺ olarak hesaplanmıştır. Bu sonuçlara göre reçine üretiminin, araştırmanın yapıldığı koşullarda ekonomik olmadığı anlaşılmıştır. Ancak reçine üretim miktarı, reçine piyasa fiyatları ve üretim maliyetlerinin değişmesi durumunda bu sonuç da değişebilecektir.

Vessel element morphology of Allagoptera campestris (Mart.) Kuntze (Arecaceae) belowground organs affected by growing conditions.

Allagoptera campestris is an acaulescent, rhizomatous palm tree that occurs in grassland and savanna areas (Cerrado). In the Santa Bárbara Ecological Station (Águas de Santa Bárbara, São Paulo, Brazil) the species is found growing in three distinct conditions: 1) in the understory of Pinus species plantations introduced in the 1970s in formerly open savanna, 2) in an area where Pinus species cultivated in the 1970s were later removed and the remaining material burned, and 3) in an open, undisturbed savanna area without the interference of pines. Anatomical studies carried out with A. campestris leaves collected in the same three areas indicated leaf plasticity in response to growth conditions. To verify whether there are differences in vessel element morphology in belowground organs, light, and scanning electron microscopy analyses were conducted on portions just below the crown, in the middle of the rhizome, and the median portions of three longer adventitious roots sampled from three plants in each area. The study reveals significant variations in vessel element characteristics of A. campestris, with roots consistently displaying longer and larger elements than rhizomes, and environmental conditions, especially in pine understory, influence vessel dimensions, and hydraulic conductivity in a negative manner.