Characteristics of the water regime in Pinus pallasiana needles from the Viyskovyi ravine anti-erosion plantation, Dnipropetrovsk region, under different forest growth conditions

The research was aimed at analysing the peculiarities of non-structural carbohydrate metabolism in the needles ofPinus pallasianaD. Don in anti-erosion plantations on the slope and in the thalweg of the Viyskovyi ravine under different forest growth conditions. The ravine is located in the Dnipropetrovsk region and belongs to the southern geographical variant of ravine forests. The studied plants grew at three experimental sites of man-made plantation: in the thalweg (forest growth conditions – mesophilic, fresh, CL2), in the middle part of the slope of the southern exposure (mesoxerophilic, somewhat dry, or semi-arid, CL1) and on the upper part of this slope (xerophilic, arid, CL0–1). Changes in glucose, fructose, reducing sugars, sucrose and starch during the period from May to October were studied.The concentration of osmotically active substances (glucose, sucrose) increases in the months with the most unfavourable hydrothermal parameters, especially in plants of mesoxerophilic and xerophilic forest growth conditions. The dynamics of fructose content revealed two maxima (July and October), when the concentration of glucose tends to increase steadily, with the highest values found in October. During the study period, the level of fructose in the needles under the arid conditions of the upper and middle parts of the slope was much lower than under the fresh conditions of the thalweg. The dynamics curve of the starch content tends to decrease from the maximum values in May to the first minimum in August. It is followed by some increase in the concentration of this polysaccharide that does not reach the previous values. The second minimum is registered in October. Such changes in the level of starch in the needles of plants are observed under all forest growth conditions. The decrease in polysaccharide content is consistent with the increase in glucose and sucrose, especially in August. A more significant increase in the concentration of soluble osmoprotective sugars (glucose, sucrose) inP. pallasiananeedles under unfavourable hydrothermal conditions compared to normal moisture conditions indicates the ability of plants to adapt to mesoxerophilic and xerophilic conditions.

Common oak (Quercus robur L.) is one of the main forest-forming and economically most valuable broad-leaved tree species of Ukraine. Nowadays, there is a weakening of the stability of natural oak forests, which is the result of a complex of reasons, in particular the action of two powerful environmental factors – anthropogenic load and global climate changes, which lead to their degradation and mass drying. This is aggravated by the poor natural regeneration of oak trees. In the south of the country, natural oak groves have been preserved in ravine forests, which perform a number of important functions (soil protection, anti-erosion, water regulation, recreation, nature protection, a reserve of valuable vegetation, etc.). In connection with the above, forest taxation analysis and regular monitoring of the state of natural oak plantations in the steppe zone of Ukraine are important, in particular under different forest growth conditions, as they significantly affect the productivity indicators of stands. The aim of the study was to analyse the influence of different forest growth conditions on the taxonomic characteristics and life status of Q. robur in the Yatsevo ravine of the Dnipropetrovsk region. The survey was carried out in the Yatsevo ravine of the Dnipro district of the Dnipropetrovsk region, which is a forest reserve of national importance and belongs to the southern geographical variant of the ravine forests. The subject of the research is the forestry and taxation characteristics and the life status of oak stands of natural origin of the large southern spur of the ravine (the first from its mouth). Experimental Quercus robur L. plants grew under different forest growth conditions: in a thalweg and on a slope with a north-eastern exposure. Test site 1 was in a thalweg with a flat topography (slope no more than 5°). Forest growth conditions CL2-3 (hygromesophilic). Site 2 was located in the middle part of the steep slope (27°). Forest vegetation conditions – CL1-2 (xeromesophilic). Site 3 with xerophilic (CL0-1) conditions was located in the upper part of the slope with a steep slope (23°). The area of each of the test sites was 1,800 m2. The studied oak stands differ in the composition of associated species. The tallest Q. robur trees under all forest growth conditions belong to the height class of 14.1-16 m. Under hygromesophilic conditions, it includes the maximum number of plants (45.5%). Plants under xeromesophilic and xerophilic conditions belong to the height class 10, 1-12 m (61.8 and 63.6%, respectively). Trees up to 4 m high are found only in the CL1-2 area. Under hygromesophilic growth conditions, the largest number of Q. robur plants has a degree of trunk thickness of 64.1-68 cm, under xeromesophilic - 16.1-20, and under xerophilic - 44.1-48 cm. Analysis of the value of the average taxon indicators (height, diameter, cross-sectional area, stock) of the Q. robur stand under different forest growth conditions allowed us to construct the following ranking series: CL2-3 > CL0-1 > CL1-2. The forest stand on the CL1-2 site has worse tax indicators compared to CL0-1, despite the higher level of moisture, which is explained by the high density of associated species and undergrowth. The vital condition index of an oak plantation under hygromesophilic conditions (CL2-3) is 86.4, under xeromesophilic (CL1-2) - 72.9, and under xerophilic (CL0-1) - 78.2. The widest range of trunk and crown pathologies is observed in thalweg conditions (8 types). On the territory of the CL0-1 hygrotop, 4 types of defectiveness were found, and on CL1-2 - 3 types. It was established that not only the level of moisture, but also the density of the tree stand affects the tax indicators and life state of Q. robur.

The influence of different forest growth conditions on the content of plastid pigments in Pinus pallasiana D. Don needles in the anti-erosion planting of the steppe zone of Ukraine was investigated. The reduction in the total chlorophyll a and b concentration in the pine needles in the area with insufficient water supply (xerophilous and mesoxerophilous hygrotopes) was found, compared with more favourable conditions for water supply (mesophilous hygrotope). The reduction in the content of green pigments in arid conditions is due to chlorophyll a. Chlorophyll b showed high resistance to moisture deficiency. There is an increase in the concentration of carotenoids in pine needles in forest growth conditions with insufficient water supply (xerophilous and mesoxerophilous), compared with more favourable conditions (mesophilous), which can be explained by the adaptive role of these pigments in the processes of stabilising the functioning of the photosynthetic apparatus in adverse environment, and it is considered as a protective reaction of P. pallasiana to the effects of drought.

Chapter 7 Nutrient and Water Management Effects on Crop Production, and Nutrient and Water Use Efficiency in Dryland Areas of China

The influence of different forest-growth conditions on the ecological and physiological parameters of Pinus pallasiana D. Don plants growing in anti-erosion planting is investigated. The experimental sites are located in the thalweg (test area 1) and on the slope of southern exposure in the lower, middle, and upper parts (test areas 2–4) of Ravine Viyskovyi (steppe zone of Ukraine). Forest-growth conditions are clay-loam soil (CL2) (mesophilic, fresh soil), СL1–2 (xeromesophilic, rather fresh), СL1 (mesoxerophilic, somewhat dry or semi-arid), and СL0–1 (xerophilic, arid) correspondently. It was shown that the growth rates of trees, the growth rate of lateral (scaffold) branches in length and thickness, needle-packing coefficient, and needle surface area of annual shoots are maximal in P. pallasianа in the thalweg in conditions of the best water supply and minimal in arid and semi-arid conditions of growth. The research revealed that the highest content of total water in the needles is characteristic of plants of fresh forest plant conditions and the smallest in arid and semi-arid areas (test areas 3 and 4), which is consistent with the forest-vegetation conditions. Sufficient contents of potassium, calcium, and magnesium in all areas and phosphorus in three areas except the middle part of the slope were found in the needles of P. pallasianа. However, insufficient content of nitrogen was found in the needles, especially in the trees of the middle part of the slope, which, together with low water supply, could cause the most significant slowdown in the growth of P. pallasianа plants precisely on this experimental site. A correlation was established between the indices of plant growth and the content of water and nutrients.

<p>The paper studies morpho-anatomical parameters of the needles of <em>Pinus pallasiana</em> D. Don. in different forest growth conditions of the antierosion afforestation in the steppe Prydniprovya. The research objects are 25-27-year-old plants, which grow in cross-sectional rows on the northern slope of wooded ravine Viyskovyi. The test Plots differ in forest growth conditions especially in the extent of water supply.In spite of the relatively high drought tolerance of <em>P. pallasiana</em>, such morphometric indices of needles as length, width and thickness are reduced in dry forest conditions. Quantitative changes in a number of indicators of the structural elements of the anatomical structure of the needles indicate adaptive changes to the lack of moisture. The formation of needles in dry forest conditions causes the formation of a thicker cuticle, an increase in the thickness of the cells of the epidermis and the hypodermis (radially in the transverse section), which reduces the loss of moisture. However, reducing the size of the conducting beams limits both the flow of water into the needle and the outflow of assimilates. In arid growing conditions, the number of resin canals in needles is reduced compared to plants of thalweg, the layer of folded parenchyma, both the adaxial and abaxial parts of the needles, is thinned.</p>

У Західному Лісостепу України Larix kaempferi відзначається дуже високими інтенсивністю росту (Id-Ie класи бонітету) та конкурентоздатністю в молодому віці, переважно витісняючи зі складу насаджень інші деревні види. У чистих насадженнях L. kaempferi нагромаджує найвищі запаси стовбурової деревини, хоча її середні висота та діаметр тут помітно менші, ніж у мішаних деревостанах. Водночас, у разі встановлення в чистих культурах модрини густоти, близької до оптимальної, середні таксаційні показники хвойної породи наближаються до таких у мішаних насадженнях. Збереженість модрини навіть і в початково чистих насадженнях характеризується високою варіабельністю, причиною чого є різні підходи до інтенсивності проведення рубок догляду. Відсутність конкретної програми вирощування модринових насаджень щодо встановлення близької до оптимальної густоти у різні вікові періоди є причиною неповного використання едафічного потенціалу типів лісорослинних умов, недоотримання значних обсягів деревини. Доцільно на території лісового фонду Західного Лісостепу та прилеглих територій створювати чисті насадження модрини Кемпфера з рівномірним розміщенням садивних місць та постійним підтримуванням високої зімкнутості деревостану. Створювати плантаційні насадження цього деревного виду доцільно в умовах дібров і судібров, бучин і субучин, яличин і суяличин. Як об’єкт плантаційного лісовирощування, L. kaempferi задовольняє низку важливих вимог: інтенсивний ріст та швидке нагромадження стовбурової деревини; проста технологія вирощування; відносно широка екологічна амплітуда, можливість успішного культивування в чистих насадженнях, цінна деревина; стійкість проти шкідників і хвороб; широкий діапазон застосування деревини; можливість ведення інтенсивного проміжного користування.

The problem of determining the dependence of the chainsaw on the density of wood, substantiation of effective options for the number of chainsaws in the assortment and whiplash method of logging is quite relevant. In the Far East of Russia, in particular, in the Amur region, the forest growth conditions are different from the western ones, and therefore, the properties of the wood differ from the generally accepted ones. The article describes forest growth conditions that influence the properties of the wood in areas of the Amur region. Using the method of density determination, the density of larch, pine and birch were studied for first time in the areas of the region. The dependence of the density on humidity, age, species, season of the year and the area of growth was found out. The results of the research showed that under humidity of 70%, the density of larch was 1088.99 kg/m3, it was 919.8 kg/m3 for pine and it was for birch 915.9 kg/m3.

Введение. Ассортимент лесопосадочного материла определяется технологиями и условиями выращивания (посевное или школьное отделение питомника, закрытый грунт), конструкцией и размерами применяемых контейнеров и другими особенностями производства. Для повышения эффективности лесовосстановления важно знать адаптационные возможности различных видов сеянцев и саженцев в определённых лесорастительных условиях. Цель исследования – оценить посадочный материал, полученный по различным технологиям и технологическим схемам и обосновать его дифференцированное применение при создании культур разного целевого назначения и в зависимости от лесорастительных условий, категорий лесокультурных площадей и других элементов типа лесных культур. Объекты и методы. Для анализа адаптационных особенностей сеянцев и саженцев, выращенных с применением различных технологий и агротехнических приёмов, использовались литературные источники, а также исследования на стационарах, заложенных на площадях Учебно-опытного лесничества ПГТУ в различных типах лесорастительных условий, категорий лесокультурных площадей и видах обработки почвы с проведением в последующем агротехнических уходов. Лесоводственный и экономический эффект предлагается рассчитывать не на отдельных этапах, а интегрированно – в период от подготовки лесокультурной площади, обработки почвы до завершения всего цикла лесокультурного производства – «главная, целевая порода заняла господствующее положение в верхнем ярусе древостоя». Результаты. Эффект сортировки и отбора интенсивно растущих особей по высоте стволика и дифференцированное применение различных видов сеянцев и саженцев при создании лесных культур обеспечивает не только их лучшую приживаемость и рост на начальных этапах, но и способствует формированию высокопродуктивных насаждений. Вывод. Дифференцированное применение различных видов посадочного материала в зависимости от лесорастительных условий, типов лесокультурных площадей, способов обработки почвы и других элементов типа лесных культур обеспечит получение лесоводственного и экономического эффекта. Introduction. The range of forest planting stock is determined by the growing technologies and conditions (a seeding division or a transplant bed of the forest nursery, growing under cover), the design and size of the containers used, and other production features. To improve the effectiveness of reforestation, it is important to know the adaptive capacities of various types of seedlings and saplings with respect to particular forest growth conditions. The aim of the study is to evaluate the planting material obtained through the use of various technologies and technological schemes and justify its differentiated use in establishing forest plantations of various purposes depending on the type of the forest growth conditions, categories of planting areas, and other elements of the type of forest crops. Objects and methods. To analyze the adaptive features of seedlings and saplings grown using various technologies and agrotechnical practices, literary sources were employed, as well as the studies carried out at the research stations created on the territory of the Educational and Experimental Forestry of Volga State University of Technology, in different types of forest growth conditions, categories of reafforesting areas and types of soil tillage with subsequent agrotechnical tending. It is proposed that the silvicultural and economic effects be calculated not at particular stages, but in an integrated manner - during the period from the planting area preparation and soil tillage to the completion of the entire silvicultural production cycle, when “the main, target species has taken a dominant position in the upper layer of the forest stand.” Results. The effects of sorting and selecting intensively growing individual plants according to their stem height along with differentiated use of various types of seedlings and saplings in forest plantation development do not only ensure their better survival and growth in the initial stages, but also contribute to the formation of highly productive stands. Conclusion. Differentiated use of various types of the planting stock depending on the forest growth conditions, reafforesting area types, soil cultivation methods, and other elements of the type of the forest plantation will yield silvicultural and economic effects.

In the system of logging machines, a factor such as the density of wood affects all components of the system. However this dependence can be more noticeable in the performance of wood felling, where logging machines have approximately the same saw body, such as a chain saw. In this regard, the problem of determining the dependence of the chainsaw on the density of wood, substantiation of effective options for the number of chainsaws in the assortment and whiplash method of logging is quite relevant. In the Far East of Russia, in particular, in the Amur region, the forest growth conditions are different from the western ones and therefore the properties of the woof differ from the generally accepted ones. The article describes forest growth conditions that influence the properties of the wood in areas of the Amur region. Using the method of density determination, the density of larch, pine and birch were studied first time in the areas of the region. The dependence of the density on humidity, age, species, season of the year and the area of growth was found out. The research results showed that in the Amur region at a humidity of 70% the density of larch varies from 745 to 1 089 kg m−3, pine from 435 to 1 081 kg m−3, birch from 403 to 878 kg m−3.

The results of forest simulation modelling of the dynamics of carbon pools and fluxes in forest ecosystems under different forest management scenarios were considered on the example of the Dankovsky forest enterprise (south of the Moscow region, subzone of coniferous-broadleaved mixed forests). The impact of such changes in forest management practices, as the reserve regime, the reduction in the proportion of forest lands as a result of residential development, and zoning of the territory with an emphasis on increasing the recreational use of forests on the carbon balance was analysed. In computational experiments, a set of Russian models was used: the dynamic model of a forest stand FORRUS-S, the model of soil organic matter dynamics Romul_Hum, the model of the hydrothermal regime of soils SCLISS. Calculations were performed for a time period of 100 years at the forestry unit level, and were also aggregated at the level of the entire forestry district. The diversity of types of forest growth conditions (FGC), together with the species diversity and the initial different ages of stands, determined significant variations of the calculated indicators of forest stands’ production, the quantity and quality of plant litter entering the soil. For all cases, model estimates of changes in carbon reserves occurred in the forest stands within the initial 40–60 years with a subsequent decrease in the calculated values. Under the conservation scenario, an increase in the organic substances reserves in forest litter and soil was observed: for FGCs C2 and C3, an increase over 100 years was approximately 5–10 kg m–2, for the remaining FGCs — at the level of 2–3 kg m–2 in terms of carbon. Under the economic use scenarios, a relative “levelling” of forest enterprise area towards the lower end of the spectrum was shown in terms of soil carbon reserves. The maximum ecosystem carbon stock was calculated for FGC C2 and C3, the minimum — for A5 and C4. Depending on the scenario, over 100 years, the total net sequestration of carbon by the forests of the Dankovsky forest enterprise (with a total area of forested land of 6836 ha) was estimated within the range of 0.15–0.57 Tg.

Биоэкологическая характеристика уникальных природных и искусственных популяций дуба на полупустынных ландшафтах Волгоградской области

Anthropogenic impact led to the destruction of forests and the destruction of a significant part of them in different regions. The process of destruction over a large area causes the new natural conditions forming. Thus, it is important to find the new methods to assess forests and forest conditions. The use of data regarding dominant, edifying, differential plant species allows assessing forest growing conditions at certain stages of community development. The results of such studies can be used for the purposes of short-term forest planning. The new research materials on the life strategy of forest plants and forest communities in general are important to do a long-term forecast of the dynamics of forest-growing conditions. Complex characteristics of plant behavior or their life strategy reflects the process of adaptation of vegetation to the emerging forest-growing conditions. The authors analyze the possibility of determining the natural conditions by the features of the life strategy of individual forest-forming species (on the example of forests of the Republic of Tatarstan). The type of the vital strategy of tree species was revealed by the indicators of the course or energy of growth, as well as life expectancy. Critically important question concern researching the main forest forming breeds in Tatarstan, which adapt to the emerging conditions, and show signs of pioneering behavior or operational strategy.

The long-term increases in average temperature and intensification of droughts which characterise the current state of the Earth’s climate system have a negative impact on forest ecosystems and can lead to a decrease in their area and deterioration of the living conditions of their components. In the conditions of the Ukrainian Steppe an important environmental, antierosion, water-protective and soil-protective role belongs to the ravine forests. The most valuable component of the ravine forests is presented by natural populations of common oak (Quercus robur L.), which are able to tolerate the arid climate typical of the steppe region. But with global warming, the endurance of this species is changing. It is believed that a significant role in plant adaptation to drought and high temperatures may belong to non-structural carbohydrates. Therefore, it is important to study changes in the concentration of these substances in the leaves of this leading species under the action of adverse hydrothermal conditions. The article analyzes the content and dynamics of soluble sugars (glucose, fructose, sucrose) and starch in the leaves of Quercus robur L. under different forest growth conditions of the ravine forest (hygromesophilic (CL2–3), mesoxerophilic (CL1) and xerophilic (CL0)). The research was conducted in the forest in the Viyskove area (steppe zone of Ukraine) in the thalweg and at different levels of slope of southern exposure. Content of glucose, fructose, sugar and starch in Quercus robur leaves was determined. It was found that when exposed to high temperatures and increasing water stress during the vegetation period in xerophilic (CL0–1) and mesoxerophilic (CL1) forest growth conditions, the concentration of both glucose and sucrose in the leaves of Q. robur increases and it becomes much higher than in conditions of more optimal water supply. At the same time, the disaccharide content increases more significantly than that of monosaccharide. The greatest amount of these sugars is observed in the driest months (July, August), when conditions for providing plants with water are the most stressful. When water stress grows the increase in concentration of glucose and sucrose is correlated with reduction of starch content. It has been found that the concentration of fructose in Q. robur leaves in droughty conditions of growing was comparable to more favourable conditions of moisture. In September, there is a decline in the content of all forms of non-structural carbohydrates in the leaves of plants of all variants compared to the previous month, especially in conditions of adverse water supply. Therefore, forest growth conditions do not affect the nature of the dynamics of soluble sugars and starch in the leaves of Q. robur, although they change their quantitative indicators. Based on the protective function of sugars under the action of stressors on plants, we can assume that in conditions of significant lack of moisture in the soil their accumulation in the leaves in areas with mesoxerophilic and xerophilic hygrotopes plays an important role in increasing Q. robur drought resistance.

The purpose of this study was to identify the possibility of using physiological parameters of growth and development of woody plants as markers of their tolerance to the arid conditions of the Mangistau desert zone. Using the generally accepted representative methods for 21 species of trees and shrubs, we studied the seasonal dynamics of the intensity of transpiration and water content of leaves, chlorophyll concentration and heat resistance. According to the magnitude of transpiration consumption of moisture, three groups of introducents were identified: weakly transpiring (<250 mg/g of raw leaves per hour), mediumtranspiring (250-500) and highly transpiring (> 500). A close correlation was established between the intensity of transpiration (IT) and the water content of the leaves of woody plants (r = 0.79). Soil moisture predetermines from 11.6 to 43.6 % of changes in transpiration flow (r = 0.34-0.66). The close connection between the transpiration intensity and relative humidity (r = -0.59) and air temperature (r = 0.46) is credible at 5 % significance level. With the amount of illumination it is associated statistically incredible (r = 0.19). Seasonal dynamics of IT in most introductions looks like a one-peak curve with a maximum in June. For the daytime course of transpiration changes, three types of rhythms are distinguished: “increasing” (from morning to evening), “falling” (from morning to evening) and “variable” (with a maximum at noon). The intensity of the transpiration process due to significant variability and multifactorial nature cannot be counted among the criteria for resistance of woody plants. However, at the same time, a significant correlation was revealed between the biological resistance of introducents and the coefficient of variation of IT. With an increase in its values, the tolerance of plants to arid habitat conditions usually increases due to their increased ability to self-regulate water exchange. Chlorophyll content is characterized by a double-vertex curve with a maximum in June and September. In the most biologically resistant species (elm elm, spinefly), its concentration is less susceptible to seasonal fluctuations. According to the collected research materials, the chlorophyll content cannot yet be considered a credible parameter of plant resistance, since it strongly depends on the bioecological properties of introduced species, especially in adverse conditions of the Mangistau desert. By heat resistance, plants are ranked in three groups: “low” (50 °С) – 3 species; “medium” (60 °С) – 8 and “high” (70 °С) – 3 taxon. As a genetically fixed bioecological parameter, weakly subject to intraspecific changes, it may well be used as a diagnostic characteristic of the introduction value of plants in arid conditions.