Pure Pine Research Articles

АСПЕКТЫ РАЗВИТИЯ СОСНЫ КРЫМСКОЙ ПРИ ИНТРОДУКЦИИ В УСЛОВИЯХ ЗЛАКОВЫХ И РАЗНОТРАВНО-ЗЛАКОВЫХ СТЕПЕЙ ПРИВОЛЖСКО-ДОНСКОГО ОКРУГА ЮЖНОЙ РУССКОЙ РАВНИНЫ

Crimean pine (Pinus nigra subsp.pallasiana Lamb.) better than other introduced tree species fits the environmental conditions of the studied region, as it is highly resistant to various pathologies and can be used to form complex (multilayered) uneven-aged multispecies stands. The significant age of the studied stands (110 and 118 years old) provides a good indication of this fact, as well as allows us to make a judgement on the features of growth and development of Crimean pine mixed with Scots pine. It should be noted that when Crimean pine is mixed with Scots pine its average trunk volume is 2.5 times higher than that of pure Crimean pine stands. Research suggests that the best plant growth pattern for the steppe conditions is when Crimean pine strips are grown between the Scots pine strips. The best plant spacing is 2x1 m and at least 2 Crimean pine rows should be spaced between Scots pine rows. Such a pattern best suits the В2 site type according to Pogrebnyak’s classification which corresponds to mesophytic mixed forests.

Effects of Organic Materials Obtained from Different Tree Species on Some Chemical Parameters of Water Quality (Study Case of Andirin-Akifiye Forest Management Unit)

Mineral substance concentrations are very important in terms of the levels of chemical quality in drinking water. A highly important source of minerals in water comes from the litter layer of the forest floor which is also a source of organic matter. This research investigates the contribution of organic litter formed in pure pine, cedar and beech forests to the quality parameters of water in the Andirin District of Kahramanmaraş province. A total of 90 organic matter samples were systematically collected from three different forest ecosystems. Some chemical properties of water solution were obtained from the organic matter using the ICP-OES device. This revealed that aluminum, boron, zinc, iron, cadmium, calcium, cobalt, magnesium, manganese, nickel and potassium parameters were present in the water. In addition, pH, EC and temperature measurements were taken. The results revealed lower amounts of chemicals in the waters obtained from the dead vegetation covers of the beech forests, showing elements such as aluminum, iron, magnesium, cobalt, and nickel levels to be 0.146 mg; 0.114 μg; 5.54 mg; 0.0006 μg and 0.0054 μg, respectively, compared to waters obtained from cedar and pine forest ecosystems. It was found that different organic materials had significantly different mineral concentrations affecting the chemical quality of the water. However, waters affected by the dead vegetation cover of the forest ecosystem were determined to comply with the standards of drinking and irrigation water according to current regulations. 

The response of the soil bacterial community and function to forest succession caused by forest disease

Abstract Forest succession is a key driver of plant communities and understanding succession is central to forest restoration. Currently, the information on the response of the microbial community to the forest succession process, however, is limited. In the present study, we investigated the dynamics of the soil bacterial community in three forest types undergoing succession caused by pine wilt disease, representing the initial pine forest, gradual mixed pine and broadleaved forest, and eventual broadleaved forest, using Illumina MiSeq coupled with Functional Annotation of Prokaryotic Taxa (FAPROTAX) analysis. The results showed that the soil pH, contents of soil organic carbon (SOC) and soil total nitrogen (TN) increased after the occurrence of initial succession and differed among the forest sites. The mixed pine forest had significantly higher bacteria biomass (p < 0.05), whereas, the total microbial biomass did not differ during the succession. The bacterial community diversity and richness increased significantly following the succession process (p < 0.05). Proteobacteria, Actinobacteria, Acidobacteria and Bacteroidetes were the dominant phyla across the succession, in which the abundance of Bacteroidetes significantly increased (p < 0.05), whereas, Planctomycetes, WPS‐2 and Burkholder decreased in abundance after succession occurred (p < 0.05). The three forests formed distinct bacterial community structures during the succession (p < 0.05), whereas, only two functional structures were clustered, in which the mixed and pure broadleaved forest did not differ. The dominant functional groups involved in the C cycle in the initial pure pine forest were replaced gradually by the groups involved in N and S cycles following the subsequent succession. The soil pH, soil TN and SOC were the most important factors affecting the bacterial community and functional structures during the succession. These results indicate that the bacterial community and function shift drastically in the early stages of succession, which reflects the changes in ecological environment caused by succession. The findings provide useful information to better understand the response of microbes to natural forest disturbance and highlight the importance of microbes during forest succession. A free Plain Language Summary can be found within the Supporting Information of this article.

Coarse Woody Debris’ Invertebrate Community is Affected Directly by Canopy Type and Indirectly by Thinning in Mixed Scots Pine—European Beech Forests

Research Highlights: Thinning and tree species alter the forest floor microclimate by modifying canopy cover, radiation, wind, and humidity. Thus, forest management can directly influence the edaphic mesofauna responsible for decomposing coarse woody debris (CWD). Background and Objectives: This research was carried out in the Southwestern Pyrenees Mountains (Northern Spain) and aimed to determine the influence of forest thinning and canopy type (pure Pinus sylvestris L. or a mix of P. sylvestris and Fagus sylvatica L.) on CWD colonization by edaphic fauna. Materials and Methods: CWD samples were collected belonging to intermediate and advanced decomposition stages, approximately 10 cm long and 5 cm in diameter. Using a design of three thinning intensities (0%, 20%, and 40% of basal area removed), with three replications per treatment (nine plots in total), four samples were taken per plot (two per canopy type) to reach 36 samples in total. Meso- and macrofauna were extracted from CWD samples with Berlese–Tullgren funnels, and individuals were counted and identified. Results: 19 taxonomic groups were recorded, the most abundant being the mesofauna (mites and Collembola). Mixed canopy type had a significant positive influence on richness, whereas advanced decay class had a positive significant influence on total abundance and richness. In addition, there were non-significant decreasing trends in richness and abundance with increasing thinning intensity. However, interactions among thinning intensity, canopy type, and decay class significantly affected mesofauna. Furthermore, some taxonomic groups showed differential responses to canopy type. CWD water content was positively correlated with total invertebrate abundance and some taxonomic groups. Our results suggest that stand composition has the potential to directly affect invertebrate communities in CWD, whereas stand density influence is indirect and mostly realized through changes in CWD moisture. As mesofauna is related to CWD decomposition rates, these effects should be accounted for when planning forest management transition from pure to mixed forests.

The influence of stand and habitat characteristics on the occurrence of pine sawflies Diprion pini L. and Gilpinia virens (Klug) (Hymenoptera, Diprionidae) in selected areas of northern Poland

Abstract Pine sawflies (Hymenoptera: Diprionidae) belong to the most common pests of Scots pine Pinus sylvestris L. in the area of the Regional Directorates of State Forests in Toruń and Gdańsk. The two most destructive species, Diprion pini L. in the area of Puszcza Bydgoska and Gilpinia virens (Klug) in Bory Tucholskie, were investigated in this study. Our main aim was to characterise the two species in the Bydgoszcz Forest District in RDSF in Toruń and Kaliska in RDSF in Gdańsk, respectively, based on data gathered during outbreaks between 1991 and 2011. For this purpose, a geometric database was created, containing information about the year of outbreak, number of larvae observed after tree felling as well as selected stand and site features including stand age and species composition, stocking index, canopy closure, site index, humidity and fertility. By analysing the occurrence of both species in relation to stand and site features, we were able to determine their environmental requirements, which are quite different from one another. D. pini preferred older stands, with a stocking index between 0.8–0.9, growing on fresh and dry coniferous sites, while species composition (share of pine), canopy closure or site index did not have any influence on its abundance. G. virens preferred middle-aged pure pine stands, with relatively open canopies, on fresh coniferous sites and poorer soils. The stocking index did not affect its occurrence.

Effect of Day or Night and Cumulative Shift Time on the Frequency of Tree Damage during CTL Harvesting in Various Stand Conditions

Thinning is one of the most important tools of forest management, although thinning operations require the use of machines which ultimately cause damage to the remaining stand. The level of damage largely depends on the human factor, and a tired, less focused operator will create more injuries in the forest. With this in mind, the objectives of this research were to find out whether the probability of tree damage caused by an operator is also affected by: (1) the part of the day (dawn/day/dusk/night), and (2) the cumulative shift time. The research was carried out in pure pine stands of different ages, density and thinning intensities. Sample plots were selected that had an increasing number of trees per hectare and growing thinning intensities were applied. The same Komatsu 931.1 harvester was used for the thinning operations in each stand. In all the age classes combined, 5.41% of the remaining trees were wounded. There was a significant influence of the part of the day on the percentage of damaged trees, which was positively correlated with the cumulative shift time. Stand conditions, such as age class and stand density, as well as thinning characteristics—thinning intensity, number of harvested trees and productivity—have different effects on the distribution of damage intensity and on probability. The results may improve the planning of operators’ work shifts in forests of various ages and densities, allowing harvester productivity to be maintained while at the same time inflicting the lowest possible level of damage.

Типологічна структура соснових насаджень Центрального Полісся

У лісовому фонді державних лісогосподарських підприємств Житомирської області, які є характерними для Центрального Полісся, соснові насадження становлять від 31,5 до 87,7 % від площі вкритих лісовою рослинністю земель. Переважають свіжі та вологі субори й сугруди. Частка чистих соснових насаджень становить у середньому 23,9 % від площі вкритих лісовою рослинністю земель і 37,3 % від площі соснових насаджень, а потенційно можлива для створення чистих соснових насаджень – 7,7 і 11,2 % відповідно. Здійснені розрахунки є підставою для підвищення стійкості соснових насаджень регіону шляхом збільшення площі мішаних насаджень на ділянках із придатними для цього лісорослинними умовами. Водночас слід брати до уваги можливість зміни гігротопів унаслідок зміни клімату останніх років.

Influence of creosote-polluted substrate on the bioremediation-potential microscopic fungi in the rhizosphere of plants

Wooden sleepers used in railways are impregnated with preservatives with fungicidic and bactericidic properties, which contain a large amount of harmful polycyclic aromatic hydrocarbons (PAHs). The aim of this research was to reveal the type of fungi in the rhizosphere of plants, which tolerate pollutants and can be involved in bioremediation process of creosote-contaminated used wooden railway sleepers. Tagetes patula grown in the substrate with 12.5% creosote impregnated used wooden sleepers chips additive is characterized by the most intensive root development and the biggest population of active fungi, therefore it is recommended for further investigation. Number of colonies of fungi in the rhizosphere of investigated plants decreased in many cases by increasing the amount of sleepers chips additive in substrate, however it was greater in the substrates with creosote treated wooden sleepers chips additives (12.5, 25 and 37.5% wooden sleepers chips) than in the pure substrate and various substrates with additives of pure Pinus sylvestris chips. This is a pioneering study searching for the local fungi species in Lithuania, which can be further utilized for the bioremediation of PAHs.

Обоснование конструкции противопожарного заслона для искусственных сосняков Прииртышья (на примере Казахстана)

На примере Казахстана предлагается вариант противопожарного заслона для искусственных сосновых насаждений ленточных боров Прииртышья, созданных полосным способом. Разработанная конструкция заслона позволяет минимизировать объем работ по его созданию и обеспечивает эффективное тушение как низовых, так и верховых лесных пожаров. Priirtishja striped piny stands are represented chiefly by pure pine stands and are characterized by very high actual burning index. Forest cultures formed by striped method are especially dangerous as concerns fire occuzend. When forming these forest culteres2 year-oldpeanlets of penussievestris planting has been carried on in raws from north to south direction according the scheme 1,5´0,5 m. Every 5 raws of forest cultures have been separated from the neighbouring ones that have been planted by analogous scheme by a stripe of 6 m in width. Planting have not been carried ont on these stripes. They served for moisture accumulation and combined with fire linteslayed out along them played part of fire barriers. Fostop the latter a compartment of 1000x1000 m in sixe is recommended to divide in Ysquare plots with total square 25 ha each with antifirebranes 8 m in vidth. We offered the article deals the variant of antifire barrier in artificial betted piny stands of Rriirtyshhya formed by striped method that makes possible to minimize the amount of work necessary to form it and quarantee effective fire suppression. We propose to replace the square blocks with rectangular 250 ´ 1000 m in size with the direction of the long side from north to south. At the same time, 6 rows of forest crops are assigned to the felling in a strip 7.5 m wide. Together with 2 strips 6 m wide, where seedlings are not planted, this will create a fire gap 19.5 m wide. In adjacent bands 7 wide 5 m thinning is carried out with cutting of knots to a height of at least 2.5 m. As a result, an effective fire barrier is created around each block of forest crops with an area of 25 hectares, which ensures rapid movement of fire fighting equipment and the possibility of starting annealing.

Parameters of Pinus sylvestris health condition and Ips acuminatus population in pure and mixed stands of Sumy region

Outbreaks of bark beetles have increased in recent years in various regions. Pine engraver beetle (Ips acuminatus (Gyllenhal, 1827); Coleoptera: Curculionidae: Scolytinae) is most common in the pine forests of many European countries. Research on its biology and spread carried out in different natural conditions, phases of pest outbreak and considered various parameters to characterize the population of the pest and forest health condition.
 The aim of the research was to compare the health condition of Scots pine stands and population parameters of I. acuminatus in its two generations in pure and mixed stands in Polissya and Forest-steppe parts of Sumy region. Research was carried out in 2017 in the pure Scots pine stands and mixed stands with Scots pine and other forest species in Polissya (State Enterprise "Seredyno-Budsky Agroforest Economy"; State Enterprise "Seredyno-Budsky Forest Economy") and Forest-steppe parts (State Enterprise "Velykopysarivske Agroforest Economy"; State Enterprise "Okhtyrske Forest Economy") of Sumy region at 26 sample plots. In sample plots, parameters of forest health condition and bark beetle population were assessed in June and in September, after completion of development of spring and summer generation of I. acuminatus. 
 By most of the parameters assessed, significant differences between sample plots in Forest-Steppe and Polissya parts of Sumy region were not found. In pure Scots pine stands the mean area of bark beetles’ foci and bark beetles’ production were larger in Forest-steppe in June, and the density of Ips acuminatus nuptial chambers in June and September. 
 In pure Scots pine stands the area of I. acuminatus focus, the number of colonized trees, the proportion of recently died trees, health condition indices, the density of egg galleries and nuptial chambers as well as young beetle’s production increased from June to September. In mixed stands the focus area, the number of colonized trees and health condition index increased insignificantly, and population parameters of I. acuminatus decreased from June to September. Pure Scots pine stands changed the health condition from "severely weakened" to "drying up" in three months, and mixed ones remained in the "weakened" category.
 In pure pine stands, the density of egg galleries and beetles of the young generation increased for three months from the lower limit of a moderate level to a high level, the density of nuptial chambers – from low to a high level. In mixed stands, all population parameters of I. acuminatus correspond to a low population level. The parameters characterizing the investigated foci of I. acuminatus in the Sumy region significantly correlated with the participation of pine in the stand composition, and in September the correlation is closer than in June. The data obtained indicate the feasibility of creating predominantly mixed pine stands.

Ecological-coenotic characteristics of <i>Cantharellus cibarius</i> Fr. and its tolerance to human impact in southern taiga and sub-taiga forests of the Kirov Region

The paper analyzes plant communities with Cantharellus cibarius Fr. in southern taiga and sub-taiga forests in the Kirov Region. Golden chanterelle occurs mostly in pure pine forests and pine forests mixed with spruce and birch of green-moss, lichen and cowberry types in young to maturing stands; the crown density is low or medium. Species richness of herbaceous-shrub storey in the studied communities varied from 5 to 29. The ecological preferences of C. cibarius, defined with Ellenberg (1974) scales, allow to characterize the species in the following way: temperate climate species, shade-resistant, rarely found in conditions of total shading; mesophyte regarding soil humidity, prefers acidic soils with low nitrogen, but, as an exception, marked on neutral soils rich in nitrogen. The differences in the species ecological preferences in conditions of southern taiga and sub-taiga are insignificant. The hemeroby index varied from 0,05 to 0,33 for the studied communities. The average share of species tolerant to human impact was 13,23%, and the share of anthropophobic species 86,77%. These data characterise C. cibarius as the species capable of tolerating moderate human impact in southern taiga subzone, but being less tolerant to human impact in sub-taiga areas and coniferous-broadleaved forests.

Formation of Soil Chemical Environment in Coastal Pinus thunbergii Parlatore Forest in Southwestern Japan

We investigated the chemical properties of precipitation and litter fall, and their effects on soil chemistry, in a coastal forest consisting of pure Pinus thunbergii stands, Pinus-dominated stands with broadleaf trees in the understory, mixed stands of Pinus and evergreen broadleaf trees, and evergreen broadleaf stands. Throughfall pH in the pure Pinus stand was significantly lower than those in the other three stands, and the soil in the pure Pinus stand was determined to be acidic (pH = ca. 5.0). In Pinus-dominated stands with broadleaf species in the understory, precipitation had a neutralizing effect in the foliage of broadleaf species in the understory of the Pinus stand and the pH levels of their surface mineral soil were significantly higher than those in the pure Pinus stand. The soil pH level was low in the pure Pinus stand, and then increased with an increasing dominance of broadleaf species in the understory. The soil pH was lowered with an increasing dominance of broadleaf species in the canopy layer. A litter layer consisting of decomposable litter of broadleaf species with low C/N ratio acidified precipitation that was deposited as throughfall on the litter surface. Nitrates in the soil-extracted water from the mixed stand and from the evergreen broadleaf stand were significantly higher than the nitrates of stands with high dominance of Pinus. Higher nitrogen flux in the mixed stand and in the evergreen broadleaf stand, as well as a lower C/N ratio of the litter of broadleaf species, accelerated nitrogen accumulation in the soil in stands with high broadleaf species dominance in the canopy compared to the Pinus-dominated stand. Thus, the accumulation of nitrogen in the soil through litter fall is a possible factor that promotes succession from Pinus stands to evergreen broadleaf stands.

Спадкові ознаки стійкості до кореневої губки сіянців сосни, вирощених із насіння дерев в осередках усихання

Pure pine stands, planted on formerly arable land, are usually infected by root rot caused by the basidiomycete fungus Heterobasidion annosum (Fr.) Bref. Currently, there are no radical methods to control the disease, despite more than 200 years of research throughout the world. Therefore, the alternative solution to this problem is the breeding of hyposensitive pine trees. The aim of the study was to identify the specificities of pine offsprings with various resistance to annosum root rot. The research was carried out in a 60-year-old pure pine stand within Kharkiv Region, infected by annosum root rot. According to the methodology of the study, trees were divided into three groups: «healthy» – no visible signs of damage outside the decline zone; «resistant» – in the open space of the gap in the disease focus without visible signs of disease; «diseased» – with signs of damage (weak growth, short pale green needles, etc.). The study of biometric parameters of the reproductive organs of Scots pine trees with various resistances to annosum root rot indicated that the disease-resistant trees had a greater average mass of a cone compared to infected and uninfected trees. Also, the mass of their 1,000 seeds was close to that of uninfected trees. In the diseased trees, these values were the least. Biometric characteristics of one-year pine seedlings grown in a greenhouse from seeds of «diseased», «healthy» and «resistant» trees showed that the characteristic feature of the one-year-old offspring of « resistant » trees grown within the root rot foci is a significantly longer root system of a seedling. Such a long root system allows it to survive under high disease background, which is probably the main criterion of pine resistance to the disease. Selected seedlings from the offspring of trees «resistant» to annosum root rot must comprise 20–30% of the planting material for afforestation. In order to grow root rot resistant pine stands, selected seedlings from the offspring of resistant trees are further recommended for the pine stand establishment on former arable land and reforestation of felling sites infected by root rot and gaps in the decline foci. Keywords: annosum root rot foci, root rot resistant trees, cones, seeds, seedling biometrics.

The effect of meteorological factors on the formation of the anatomical structure of Pinetum sylvestris myrtilloso-tufosum on a drained peatland

This paper investigated wood structure formation of pure pine stands (Pinus sylvestris L.) depending on meteorological indicators. Influence of average temperature and sum of precipitation on wood structure at the level of annual growth and at the level of xylem cellular structure is presented. Three series of experimental objects in the boreal zone of the European part of Russia was observed: naturally formed mature stands, plots passed by thinning, plots passed by thinning with the fertilizers application. It is shown that fluctuations of average temperature have a more significant role in the formation of the zone of early wood than late wood. Statistical analysis has determined that the effect of average temperature and precipitation factors on the formation of macrostructure elements of wood is higher in the naturally formed stands, than in the stands that have been treated. It was identified that thinning and application of fertilizers increase the role of meteorological factors influence on changes in the number of xylem cells in annual growth. At the same time, the size of xylem cells and the thickness of cell walls are in a more significant correlation with weather factors in stands unaffected by treating.

Pine rosin identified as a toxic cannabis extract adulterant

Pine rosin (colophony) has been identified as a potentially new adulterant in cannabis oil. Its inhalation toxicity poses a significant health concern to users. For example, pine rosin fumes are released during soldering, and have been cited as a causative agent of occupational asthma. Symptoms also include desquamation of bronchial epithelium, which has also been observed in e-cigarette or vaping product used-associated lung injury (EVALI) patients. The sample analyzed herein was acquired from a cannabis industry source, also contains medium chain triglycerides and oleamide, the latter of which is a hypnotic that is commonly found in the synthetic marijuana product Spice, or K2. A combination of proton nuclear magnetic resonance (1H NMR) and high pressure liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESIMS) was used to unambiguously identify major pine rosin ingredients such as abietic and other resin acids. Comparison to commercial samples of pure pine rosin confirmed the assignment.

Spatial lag effect of aridity and nitrogen deposition on Scots pine (Pinus sylvestris L.) damage

Scots pine (Pinus sylvestris L.) is a widespread tolerant forest tree-species; however, its adaptability to environmental change differs among sites with various buffering capacity. In this study, we compared the spatial effects of aridity index (AI) and nitrogen deposition (ND) on biomass density in natural and man-made pine stands of differing soil fertility using geographically weighted multiple lag regression. Soil fertility was defined using soil series as zonal trophic (27.9%), acidic (48.2%), gleyed (15.2%) and as azonal exposed (2.5%), maple (2.4%), ash (0.8%), wet (2.1%) and peat (0.9%) under pine stands in the Czech Republic (Central Europe; 4290.5 km2; 130–1298 m a.s.l.). Annual AI and ND in every pine stand were estimated by intersection between raster and vector from 1 × 1 km grid for years 2000, 2003, 2007 and 2010 of severe non-specific forest damage spread. Biomass density was obtained from a MODIS 250 × 250 m raster using the enhanced vegetation index (EVI) for years 2000–2015, with a decrease in EVI indicating non-specific damage. Environmental change was assessed by comparing predictor values at EVI time t and t+λ. Non-specific damage was registered over 51.9% of total forest area. Less than 8.8% of damaged stands were natural and the rest (91.2%) of damaged stands were man-made. Pure pine stands were more damaged than mixed. The ND effect prevailed up to 2007, while AI dominated later. Temporal increasing ND effect under AI effectiveness led to the most significant pine stand damage in 2008 and 2014. Predictors from 2000 to 2007 afflicted 58.5% of non-specifically damaged stands at R2 0.09–0.76 (median 0.38), but from 2000 to 2010 afflicted 57.1% of the stands at R2 0.16–0.75 (median 0.40). The most damaged stands occurred on acidic sites. Mixed forest and sustainable management on natural sites seem as effective remediation reducing damage by ND.

Pyrolysis and Carbon Dioxide Gasification Kinetics of Pine Cones and Lignite Blends

This study determines the kinetic parameters of blended Pinus kesiya, Pinus elliottii, and Indonesian lignite in co-pyrolysis and co-gasification. Nine binary blends and three ternary blends were tested using a thermogravimetric analyzer. Pyrolysis was carried out in an argon atmosphere and DTG plots showed that Pinus kesiya had the highest maximum pyrolysis rate while Pinus elliottii had the lowest starting decomposition temperature. Similarly, blends with Pinus elliottii had lower maximum pyrolysis rates and lower starting decomposition temperatures than those with Pinus kesiya. Ternary blends, however, have starting decomposition temperatures and maximum pyrolysis rates close to those of pure Pinus elliottii. The Kissinger-Akahira-Sunose (KAS) model was used to obtain the reaction rate constants and activation energies of the pyrolysis reactions of various blends. Co-gasification of the mixtures was also done in a CO2 environment at gasification temperatures of 700°C, 800°C, and 900°C. The conversion-time data obtained were fitted using five different gas-solid reaction models.

Роль метеорологічних чинників у зменшенні продукції верхівкового короїда в соснових деревостанах Східного Полісся

Інтенсивне поширення групових і куртинних осередків усихання в соснових насадженнях Східного Полісся розпочалося після дуже посушливої другої половини вегетаційного періоду 2016 р. та тривало протягом 2017–2018 рр., які вирізнялися екстремально посушливими умовами на початку вегетаційних періодів, коли гідротермічний коефіцієнт за Г. Т. Селяніновим становив 0,1–0,5, а дефіцит атмосферних опадів – 10–30 % у різні місяці. Після сприятливого для росту дерев початку вегетаційного періоду 2019 р. з гідротермічним коефіцієнтом 1,7 у результаті надлишку атмосферних опадів за пониженої температури поширення патологічного всихання сосняків у Східному Поліссі істотно знизилося та стабілізувалося з переважанням поодинокого та групового типів. Відновлення водозабезпечення дерев активізувало процеси смоловиділення, що інтенсивно перешкоджало спробам заселення дерев верхівковим короїдом на відносній висоті стовбура 0,51–0,75 і меншій. Середні значення продукції вздовж стовбурів заселених дерев становили від 29 до 33 шт.∙дм-2 молодих імаго.

Стан, структура і продуктивність соснових лісів ДП «Лиманське ЛГ»

Розглянуто особливості структури, продуктивності та стану соснових лісів ДП «Лиманське ЛГ» на типологічній основі. За результатами аналізу бази даних «Лісовий фонд» встановлено, що в лісовому фонді домінують чисті соснові деревостани у свіжих і сухих борах та свіжих суборах, що визначається кліматичними умовами та співвідношенням типів рельєфу. Соснові деревостани є середньопродуктивними: середній клас бонітету становить І,7, середня повнота – 0,76. Найбільші частки за площею займають деревостани VI–VIІІ класів віку.З використанням польової ГІС Field-Map на дослідних ділянках проведено оцінювання основних компонентів лісових екосистем, визначено санітарний стан соснових деревостанів. За станом соснові ліси характеризуються як ослаблені та сильно ослаблені. Індекс стану без урахування сухостою становить від І,53 до ІІ,70. Найгірший стан визначено на ділянках, пошкоджених пожежами (ІІ,49–ІІ,70). Встановлено основні чинники, що негативно впливають на стан лісів (зміна рівня ґрунтових вод, ураження хворобами, пошкодження пожежами).

Пірогенні зміни ґрунтів соснових насаджень

Унаслідок низових пожеж відбуваються зміни фізико-хімічних і біологічних властивостей ґрунтів. Досліджено пірогенні зміни властивостей ґрунтів у чистих соснових лісах, що ростуть у різних природних зонах України. У соснових насадженнях після низових пожеж у результаті як часткового, так і повного згорання підстилки утворюється попіл, що в подальшому впливає на хімізм верхнього шару ґрунту. Подібні особливості відзначали в різних природних зонах України. Надходження попелу в ґрунт призводило до зростання рН верхнього гумусового горизонту. Оскільки таке явище є одноразовим, то в подальшому після дощів значення рН водного витягу знижувалося до природнього рівня. Причиною пірогенних змін є високий уміст у попелі лужних металів. Інтенсивність змін реакції та вмісту лужних катіонів залежить від рівня згорання підстилки. Найбільш відчутними є зміни у разі повного згорання підстилки. Зазначені зміни мають поверхневий характер, тобто переважно притаманні лише верхньому шару ґрунту. На більшій глибині реакція не відрізняється від контролю.