Dynamics of Branch and Stem Apical Growth in the Progenies of Plus Pine Trees (Pinus sylvestris L.)

The relationship between the characteristics of the linear growth of branches and stems was studied, as well as the possibility of distinguishing between various Scots pine (Pinus sylvestris L.) genotypes. The objects of research were experimental plantations of the half-sib progenies of pine plus trees aged 10–11 years. The annual increments of the stem and differently oriented branches were measured. Correlation, regression and data analysis methods developed by the authors were used. The time dynamics of the obtained values were studied by comparing the regression line slopes describing the interrelation of axial increments and by analysis of the frequency spectra of the Integral Parameter of Characters Sequence applied earlier. The analysisof the obtained results has shown the existence of a significant relationship between auxiblast linear growth within the two adjacent years and a weak interrelation of the characteristics of branch and stem morphogenesis. The possibility of distinguishing Scots pine half-sib families by comparing the dynamics of branches and stem apical growth is described. Keywords: Scots pine, apical growth of branches and stems, genotypic and phenotypic variability, impact of environmental factors on growth, morphogenesis of woody plants, growth modelin

Edge Effect: Growth and Morphogenetic Features of Scots Pine Trees in Forest Parks and Natural Stands

The degree of development and depth of edge effect are studied in some fragments of forest-park stands under long-term urbanization impact (in the city of Yekaterinburg, Russia) and in natural forests using the method of transect investigation. The method of quantitative assessment of tree stem and crown growth features by a set of morphological characteristics was used. The objects of the research included the edges of Scots pine stands. The edge effect was determined by two of the five studied characteristics: foliation and branchiness, which characterize the level of the development of the tree assimilation apparatus. The general trends indicate an increase in the development of these characters in natural stands and decrease in the forest park at increased distance from the edge. The nonlinear development of morphological characteristics along the transects is due to different types of tree responses on the impact of determining morphogenesis factors. Four statistically significant different zones were identified in the natural stands at distances of 0-75, 100-125, 150-175, and 200-225 m from the forest edge and only two zones were differentiated in the forest park. The unified approach to data analysis suggests the edge effect in both habitats at a distance of 75-100 m from the forest edge according to branchiness and 100-125 m according to foliation. Several types of morphogenetic tree responses, distinguished by the degree of foliation and branchiness variation under edge effect impact, are revealed.This study was supported by the Integrated Program of the Ural Branch of the Russian Academy of Sciences for 2018-2020 (grant no. 18-4-4-10) and performed under the State Assignment of the Botanical Garden, Ural Branch, Russian Academy of Sciences

Seasonal changes in chlorophyll and carotenoid content in needles of scots pines (pinus sylvestris l.) Exposed to the thermal field of a gas flare

Seasonal changes in chlorophyll (Chl) and carotenoid (Car) content were analyzed in needle samples from young Scots pines (Pinus sylvestris L.) growing in the thermal field zone at various distances from the petroleum gas flare. Experiments were performed in Khanty Mansi Autonomous Area (Yugra) of Russia throughout the autumn–winter–spring period. Two hypotheses were subject to verification: (1) the thermal field of petroleum gas combustion flame imitates the influence of climate warming on plants, thus affecting the pigment complex of the photosynthetic apparatus (PSA) in pine needles; (2) transformations of PSA pigment complex in pine needles throughout the autumn–winter–spring period are sensitive to a long-term rise in ambient temperature by 1–2°С. In the winter period, the seasonal dynamics of certain PSA parameters comprised maxima and minima that are supposedly due to the regulation of Chl and Car content upon changes in air temperature. In trees growing under divergent thermal conditions, seasonal changes of these parameters were not synchronous. Analysis of seasonal changes revealed that winter-related transformations of the PSA structural–functional condition in needles are subject to consistent variations at different distances from the gas flame. The PSA activity of needles throughout the studied period was higher near the flame and decreased with the distance from the gas flare. When Chl content in needles decreased in autumn–winter, the smallest reduction was observed in the location near the gas flare (site I) where temperature was 1–2°C higher than the background level. The intermediate decrease in pigment content was noted at a moderate distance from the flame (site III), while the most pronounced decrease occurred at the largest distance from the gas flare (site VII). At the same time, the Chl a/b content ratio in needles was consistently lower for trees located at site I than at site VII. Hence, the amount of light-harvesting complexes in chloroplasts from trees grown at site I was higher than the amount of photosystems in the same chloroplasts. The Chl (a + b)/Car ratio in needles of trees grown near the gas flare (site I) was higher than in locations III and VII. This ratio displayed two significant peaks in the winter dynamics, which was supposedly due to the sufficient preservation of green pigments. Divergent seasonal changes in Chl and Car content and their dissimilar correlations with air temperature indicate that the pools of these pigments are controlled by different mechanisms. The actual Chl content, determined by the balance of pigment degradation and synthesis, should depend on the environmentally modified Chl synthesis and on the protective function of Car. Photosynthesizing cells produce additional amounts of carotenoids during autumn–winter, thus preventing the photodegradation of Chl in the period from autumn to late spring. © 2021, Pleiades Publishing, Ltd.This work was supported by the Comprehensive Program of the Ural Branch of the Russian Academy of Sciences for 2018–2020 (project no. 18-4-4-10) and by a state assignment to the Institute Botanic Garden of the Ural Branch of the Russian Academy of Sciences

Seasonal Dynamics of Content of Antioxidant System Component in Needles of Scots Pine (Pinus sylvestris L.) Trees Situated in the Local Warming Impact Zone

The seasonal changes in a period of low temperatures and characteristic correlations of some antioxidant system (AOS) components in pine needles influenced by a gas flare are investigated in this study. The parameters taken are total water content (TWC) in needles, peroxidase activity (AP) and selected elements of the antioxidant system of needles, such as content of carotenoids (Car), ascorbic acid (AA), catechins (Cat) and flavanols (Fl). The needles come from Scots pine trees (Pinus sylvestris L.), which grow in a gradient of environmental conditions formed in the zone of thermal field of the gas flare impact (at various distances). The gas flare is situated on the territory of the Khanty-Mansiysk Autonomous Okrug (UGRA) of Russia. Three hypotheses were subject to verification: 1) the thermal field of the gas flare during the low temperature period affects the water exchange and the AOS state of needles; 2) increase in temperature of the environment in the flare impact zone during the autumn-winter period causes the decrease in amount of moisture in needles, which is a trait of oxidative stress in cells; 3) in the functioning of a needle's AOS, there are correlations between its components, which values depend on distance from the gas flare and environment created by it. It was found that in the thermal field gradient of the flare, there is neither an additional reduction in TWC in needles compared to the background nor signs of change in the state of AOS corresponding to the oxidative stress in the cells. The greatest impact of the gas flare on characteristics of the physiological state of pine needles is observed in the section closest to the flare. It reveals in the higher values of AP, TWC, Car and decrease in concentration of Fl and AA. The seasonal dynamics of the studied traits values do not correlate with the temperature of the environment. It indicates the indirect effect on the regulation of needle's AOS activity. The factor and correlation analysis of the data indicate a difference in physiological state of pine needles at different distances from the flare. There is no domination of any processes in the functioning of AOS components. The observed correlations between the studied properties change according to distance to the flare. The most stable is a negative AP relationship with ofter parameters, which rise with the increased distance from the flare. The consistency degree of separate AOS components functioning is maximal in background conditions and decreases when approaching the flare. This fact is explained by the modifying effect of the flare on physiological and biochemical processes of the needle's adaptation to specific climatic conditions of the environment.Исследовали сезонные изменения в период низких температур и характер корреляционных связей для содержания общей воды в хвое, пероксидазной активности и содержания отдельных компонентов антиокислительной системы хвои: каротиноидов, аскорбиновой кислоты, катехинов и флавонолов – у деревьев сосны обыкновенной (Pinus sylvestris L.), произрастающих в градиенте условий среды, формируемых в зоне влияния теплового поля газового факела (на разном удалении от него) на территории Ханты-Мансийского автономного округа – Югры (Россия). Проверены 3 гипотезы: 1) тепловое поле газового факела в условиях низких температур влияет на водный обмен и состояние антиокислительной системы хвои; 2) повышение температуры среды в зоне влияния факела в осенне-зимний период приводит к уменьшению количества влаги в хвое, которое вызывает состояние окислительного стресса в клетках; 3) в работе антиокислительной системы хвои между ее отдельными компонентами существуют взаимосвязи, характеристики которых трансформируются в зависимости от условий среды, определяемых удалением от газового факела. В градиенте действия теплового поля факела не наблюдается дополнительного по сравнению с фоном снижения содержания общей воды в хвое и признаков изменения состояния антиокислительной системы, характерных для окислительного стресса. Влияние газового факела на показатели физиологического состояния хвои максимально на ближней к факелу секции. Оно проявляется в виде увеличения пероксидазной активности, количества общей воды, каротиноидов и в снижении содержания флавоноидов и аскорбиновой кислоты. Сезонная динамика изученных показателей не коррелирует с температурой среды, что говорит о ее непрямом действии на регуляцию активности антиокислительной системы хвои. Факторный и корреляционный анализ данных свидетельствуют об отличии физиологического состояния хвои на разном удалении от факела. В функционировании компо- нентов антиокислительной системы хвои не наблюдается доминирования отдельных процессов. Взаимосвязи между изученными показателями изменяются с удалением от факела. Наиболее устойчивой является отрицательная связь пероксидазной активно- сти с остальными показателями, усиливающаяся с увеличением расстояния до факела. Степень согласованности работы отдельных компонентов антиокислительной системы максимальна в условиях фона и уменьшается с приближением к факелу. Это объясняется модифицирующим влиянием факела на физиолого-биохимическиеThis work was financially supported by the Comprehensive Program of the Ural Branch of the Russian Academy of Sciences for 2018-2020 (Grant No. 18-4-4-10) and within the state assignment of the Federal State Budgetary Institution of Science ?Institute Botanic Garden of the Ural Branch of the Russian Academy of Sciences?

Ecological zoning of forests in areas exposed to industrial air pollution

Morphometric characteristics of the growth of forest stands located at different distances from a large copper-smelting plant were estimated. The set of diagnostic parameters obtained was used for calculating summary parameters of the state (SPSs) of the forest stands and to grade their values for zoning the forests. The results of using semivariance analysis demonstrated the appropriateness of kriging, a method of spatial interpolation, for mapping the surfaces of the state of forests. The map-scheme of the zones differing in the state of forest stands (made on the basis of summary parameters) was compared with the topographic map of the area, which made it possible to estimate the effect of large forms of relief on the location and configuration of the zones.This study was supported by INTAS, project no. 93-1645

The impact of ozone fumigation and fertilization on chlorophyll fluorescence of birch leaves (Betula pendula)

The impact of ozone fumigation on chlorophyll a fluorescence parameters and chlorophyll content of birch trees grown at high and low fertilization were studied for 6-, 8-, and 12-week old leaves. Fluorescence parameters were measured with a portable fluorometer with its fibre optics tightly inserted in a gas exchange cuvette at light intensities from 0 to 220 μmol photons m-2 s-1. Ozone caused significant changes of primary photosynthetic reactions: a decrease of the quantum yield of photosystem II and an increase of non-photochemical quenching. In all leaves a biphasic light response of nonphotochemical quenching was observed. Ozone fumigation shifted the onset of the second phase from a PFD of about 60 μmol m-2 s-1 to about 30 μmol m-2 s-1. While the fertilizer concentration had no influence on this character, high fertilization supply of plants partially reduced O3-induced damage. The light responses of Ft, Fm' and NPQ observed in birch leaves grown in O3-free air indicate the existence of at least two different processes governing energy conversion of the photosynthetic apparatus at PS II in the range of PFD 0-200 μmol photons m-2 s-1. The first phase was attributed to a rather slowly relaxing type of non-photochemical quenching, which, at least at low PFD, is thought to be related to a state 1-2 transition. The further changes of the fluorescence parameters studied at higher PFD might be explained by an increase of energy-dependent quenching, connected with the energization of the thylakoid membrane and zeaxanthin synthesis. A major effect of ozone treatment was a lowering of PS II quantum yield. This reflects a reduction of PS II electron transport and corresponds to the reduction of CO2-fixation observed in ozonated leaves.The impact of ozone fumigation on chlorophyll a fluorescence parameters and chlorophyll content of birch trees grown at high and low fertilization were studied for 6-, 8-, and 12-week old leaves. Fluorescence parameters were measured with a portable fluorometer with its fibre optics tightly inserted in a gas exchange cuvette at light intensities from 0 to 220 μmol photons m-2 s-1. Ozone caused significant changes of primary photosynthetic reactions: a decrease of the quantum yield of photosystem II and an increase of non-photochemical quenching. In all leaves a biphasic light response of non-photochemical quenching was observed. Ozone fumigation shifted the onset of the second phase from a PFD of about 60 μmol m-2 S-1 to about 30 μmol m-2 s-1. While the fertilizer concentration had no influence on this character, high fertilization supply of plants partially reduced O3-induced damage. The light responses of Ft, Fm′ and NPQ observed in birch leaves grown in O3-free air indicate the existence of at least two different processes governing energy conversion of the photosynthetic apparatus at PS II in the range of PFD 0-200 μmol photons m-2 s-1. The first phase was attributed to a rather slowly relaxing type of non-photochemical quenching, which, at least at low PFD, is thought to be related to a state 1-2 transition. The further changes of the fluorescence parameters studied at higher PFD might be explained by an increase of energy-dependent quenching, connected with the energization of the thylakoid membrane and zeaxanthin synthesis. A major effect of ozone treatment was a lowering of PS II quantum yield. This reflects a reduction of PS II electron transport and corresponds to the reduction of CO2-fixation observed in ozonated leaves.We gratefully acknowledge data on chlorophyll content from Dr. W. Landolt and the technical assistance of Mrs. C. Rhiner, Mr. U. Bühlmann, Mr. P. Bleuler and Mr. A. Bur-kart in tending the plants and operating the O3 fumigation. We also thank Mrs. M.J. Sieber for correcting the English text. The study was financed through the ‘EUREKA 447 EUROSILVA’ program of the Swiss ‘Bundesamt für Bildung und Wissenschaft’ and through a joint agreement between The Swiss Federal Institute for Forest, Snow and Landscape Research and The Ural State Forestry Engineering Academy for a sabbatical of the first author in Switzerland, and INTAS (Brussels, Proj. Nr. 93–1645) for financial support of S.S. and W.B

Application of the generalized state index determination to ecological monitoring of forest in polluted areas

A new kind of quantitative model for assessment of state of Scotch pine tree stands growing in industrial polluted areas of Middle Urals is described. The model is based on the use of two types of indices - state indices and generalized state indices - which are calculated from morphological and physiological characteristics (parameters) of tree stands. Morphological parameters include average values of tree diameters, heights, and annual increments while physiological characteristics include chlorophyll a content and photochemical quantum yield of photosystem II in pine needles. It is shown that the use of the combination of diagnostic parameters as in the model described provides more credible assessment of tree stands state than the use of separate diagnostic characteristics