Home – Home – Jornals – Siberian Journal of Forest Science 2018 number 4

The nature of catastrophic steppe fires in Siberia, which in recent decades have been spread over thousands of hectares each year, leading to economic losses, and losses of lives and livestock, is being considered. The paper follows spring (March-May) steppe and forest-steppe fires using satellite monitoring data. In the 10-year time interval of 2008-2017 a positive logarithmic trend in annual burned area of steppe fires has been identified. The trend in the number of fires is characterized by periodic variations in relation to the average values, which do not seem to increase. It has been shown that in today’s context the occurrence and spread of catastrophic steppe fires in Siberia are determined by the anomalies of hydrometeorological conditions. Also, natural and anthropogenic factors that cause the occurrence and spread of steppe fires are analyzed. A system of prevention is discussed, as well as technological solutions for the protection of settlements and facilities. It is proposed to focus attention not only on the immediate control of fires and the elimination of their effects, but also on the implementation of comprehensive preventive measures to aim at specific economic targets. As an example a technology is proposed to construct fire control barriers that would prevent the spread of steppe fires and scattering of burning particles to residential and structural settlements. These measures should have a positive effect on the national economy by significantly reducing the cost of rebuilding settlements after fires, saving lives, livestock and infrastructure.

The distribution of individuals of the intermediate form of Norway spruce Picea abies (L.) H. Karst., and Siberian spruce P. obovata Ledeb., distinguished according to the metric parameters of the seed scales, was studied in extensive areas of the range from the Ukrainian Transcarpathia in the west to the Republic of Sakha (Yakutia) in the east. Intrapopulation frequency of intermediate phenotypes of European and Siberian spruce is characterized by a great variety. The coefficient of geographical variation of the frequency index is 73 %. According to the frequency of intermediate phenotypes, the entire population (107 of 126) is divided into three large groups: populations with a very low frequency (groups I, II and VIII, IX), in which it reaches 12-15 %; in groups III and VII, the frequency of such phenotypes is about 30; in groups IV, V, VI, 60-70 (up to 80) %. Groups of populations with predominance of individuals of intermediate phenotypes, in essence, represent an intermediate form of European and Siberian spruce. Populations in groups I-III, in which the phenotype of European spruce is found, represent this spruce, and in groups IX, VIII, VII one can observe the predominance of individuals of Siberian spruce phenotypes, these populations represent Siberian spruce. Populations in groups III and VII are transitional to the intermediate form of European and Siberian spruce. The populations with different frequencies of intermediate phenotypes can be studied to solve the problems of intraspecific taxonomy, e.g. in silviculture with a view to develop the guidelines for multiple forestry practices, since in geographical variability the shape of seed scales is strongly related to many other biological features.

An efficient system for the in vitro propagation of the endangered medicinal and winter-hardy ornamental plant, Rhododendron mucronulatum Turcz., through high frequency shoot induction from seedlings and in vitro -derived apical shoots was developed. While testing different zeatin (Z) concentrations in the seedling culture, both axillary shoot regeneration and adventitious shoot formation on hypocotyls were observed. The highest frequency of shoot regeneration from seedlings (80 %), including formation of adventitious buds on hypocotyls (25 %), was recorded in the presence of 1.0 µM Z. The highest adventitious shoot numbers per explant (31.12 ± 6.19) were formed under 2.5 µM Z. Histological examination confirmed that adventitious buds directly originated from parenchymal cells of the hypocotyl. The effect of different concentrations of 2-isopentenyladenine and Z alone as well as in combination with indole-3-acetic acid (IAA) on axillary shoot proliferation from apical shoot explants was studied. The highest regeneration frequency (100 %) and shoot multiplication (9.70 ± 0.63) with a maximum length (15.75 mm) were obtained by using a combination of 0.1 µM IAA with 1.0 µM Z. The most efficient root formation was achieved through 4-hour pulse treatment with 148.0 µM indole-3-butyric acid followed by ex vitro rooting in a mixture of peat and sand (1 : 1). This study contributes to conventional and genetic-engineering breeding programs for creating new frost-resistant cultivars and developing a strategy for R. mucronulatum germplasm conservation, as well as commercial large-scale propagation.

Studies of Pinus sylvestris L. forests in the impact (5-10 km) and buffer (11-40 km) technogenic pollution zones in the vicinity of a large industrial centre Usol’e-Sibirskoe of Irkutsk Oblast have been conducted in 2013-2016. Changes of biogeochemical indexes (acid-base balance, accumulation and migration of pollutants and biogene elements) in the components of a forest ecosystem, such as pine trees, organic litter, and soil horizons were determined. It has been shown that the displacement of acid-base balance to the alkaline range and the active migration of pollutant elements in soil horizons and organic litter are the key processes that cause the violation of the exchange reactions of the Ca²⁺, Mg²⁺, K⁺, Na⁺ cations in a soil absorbing complex as well as decreasing the migration of nutrient elements to the root systems of pine trees. The pronounced changes in the acid-base balance, the high accumulation of pollutant elements, binding of biogenic elements by pollutants in the horizons of soil profiles and plant tissues lead to the disruption of nutrition and inhibition of growth processes in pine trees. The biogeochemical indicators under study are characterized by interconnected changes in the components of the forest ecosystem and can serve as adequate criteria for assessing its state under technogenic pollution. Therefore, the obtained results provide information on the nutrient cycling in pine forests, role of industrial emission elements, their migration and accumulation in individual components of the ecosystem.

The search for an optimum value to constrain boundary parameters in distribution models can be (and is) laborious and time-consuming. The accuracy of a distribution fit depends on the predetermined values of the boundary parameters. In this study, we applied the extreme value distributions derived from the generalized extreme value (GEV) in assigning the optimum constant to a distribution with boundary parameters. GEV subfamily (type 1), Gumbel’s distribution, was used to generate constant values which were used as a fraction of the minimum and maximum diameter and height data. The effectiveness of these values was established using five distribution models: logit-logistic (LL), Burr XII, Dagum, Kumaraswamy, and Johnson’s S_B distributions. The distributions were fitted with maximum accuracy to the diameter and height data collected on 90 Eucalyptus camaldulensis Dehn sample plots. Model assessment was based on negative log-likelihood (-ΛΛ), Kolmogorov-Smirnov ( K-S ), Cramér-von Mises ( W ²), Reynold’s error index ( EI ), and mean square error ( MSE ). The result showed that the performance of the distributions was improved, especially for the height distribution, compared to other constant values. Gumbel’s distribution can be applied whenever (where) a boundary constraint is to be imposed on the location and scale parameters of the distribution models.

The dynamics of radial growth of tree stem developing in changing conditions of the city of Krasnoyarsk was studied. For Krasnoyarsk, The problem of creating an environment favorable for people living in Krasnoyarsk is an urgent issue and its integral part is deveping green areas to protect the environment Eight tree species were used to improve the landscape of the city of Krasnoyarsk: Scotch pine Pinus sylvestris L., Colorado spruce Picea pungens Engelm., drooping birch Betula pendula Roth., Siberian elm Ulmus pumila L., balsam poplar Populus balsamifera L., mountain ash Sorbus aucuparia L., Maak bird cherry tree Padus maackii Rupr., and dwarf apple tree Malus baccata (L.) Borkh. The width of the radial growth of the stems was measured during the lifetime of the model trees and the averaged growth paths were obtained for the five sample plots, showing different levels of contamination. On heavily contaminated sample plots, the Siberian elm, balsam poplar, Maak bird cherry tree and dwarf apple tree throughout their life form relatively narrow annual rings (up to 3 mm). It is concluded that these tree species can be used as indicators of anthropogenic pollution of the sit. Drooping birch, Siberian elm, Maak bird cherry tree, and dwarf apple tree on sites with a high level of contamination are characterized by high rate of decrease in the width of annual rings with aging, which shortens the effective life of these plants. Based on the results obtained, preliminary recommendations on the use of the tree species in the urban environment were formulated, taking into account the characteristics of their growth.

The objects of the study were forest shelterbelts represented mainly by pure and mixed stands of black poplar Populus nigra L. in the Republics of Khakassia and Tyva. The sites differed according to soil conditions: southern chernozems, ordinary chernozems, sandy spilled soils. The stand structure along DBH distribution rows showed pure stands to possess a right-asymmetric shape with non-expressed maximum points. Mixed stands are characterized by a comb-shaped form with several extremum points. In comparison with mixed stands, pure (monospecific) forest belts are more stable. Black poplar is characterized by different state of trees growing in favorable conditions in pure stands (8.0-53.6 % - healthy trees) compared to a weakened state in mixed stands (12.9 % - healthy trees). Three growth strategies have been intensive, medium, and moderate. The strategy of intensive growth is characteristic of pure tree stands growing on ordinary chernozems. The strategy of moderate growth is characteristic for a mixed stands growing on southern chernozems. Black poplar has a more full-boled stem form in comparison with other tree species of forest shelterbelts from other administrative regions. The difference in the ratio of tree heights and diameters is due to the soil conditions,formation of shelterbelt, many other anthropogenic and natural factors. The stereometric method was used to obtain an empirical formula for determining the wood stock of black poplar. Complex evaluation of black poplar growth in forest shelterbelts in the south of Central Siberia made it possible to determine the features of agrotechnology, structure, the conditions of tree growth, stem shape, identification of the types of site conditions, and to choose the methods for assessing the current productivity of the stands. The obtained results contribute to developing the regulatory framework, and introduce economic measures for the creation, cultivation and care of black poplar forest belts in Central Siberia.

The paper reviews research papers, develops recommendations for forest regulatory documents. Some deficiencies in the current regulatory framework are revealed. Traditionally, the system of normative documents had a hierarchical structure. The upper level contained basic principles and the most general provisions, while regional level documents focused on local features of forest growth, and also analyzed possible differences within the region. In addition to the geographical aspect, progress in the development of forestry practices, new scientific data and gradual changes in the forest fund were also taken into account, which encouraged periodic updating of standards. The last time it happened more than 20 years ago. The current standards regulating the main stages of forest growing - reforestation, forest care and felling of mature tree stands - are considered. Specific examples illustrate problems, caused by the imperfection in forest legislation, insufficient study of natural and economic characteristics of the regions, progress in the development of logging equipment and considerable changes in the forest fund. It is pointed out that there is a need for normative measures for recording the costs of carrying out activities. It is noted that these shortcomings are a consequence of neglect of the principal issues of domestic forestry. It is shown that system for assessing stand thinning quality is imperfect and the interpretation of the results of the work is ambiguous. It is proposed to base the assessment on absolute indicators, as is accepted in international practice. The urgent need to plan biodiversity conservation activities taking into account the peculiarities of natural and territorial complexes is shown. We suggest to improve the situation, with proposals aimed at creating conditions to intensify forestry production and restore resource potential of taiga forests.

Increasing urbanization makes people study the environmental and sanative functions of suburban forests. Forest attendance of over two thousand people per day per hectare in a season is facilitated by a dense network of roads and trails in suburban forests near Krasnoyarsk, so that residents can penetrate into forest interiors. Over recent years the scale of recreational forest usage is constantly increasing. Currently, uncontrolled recreational use of forests prevails. Fires are often human-caused. In the paper an assessment of relative inflammability of suburban recreational pine forests near Krasnoyarsk is provided. An analysis of the distribution of forest fires by the months of fire season and origins of their occurrence was made. An objective indicator of the inflammability norms for each particular year and the methodology for their calculation were proposed. The calculation of the normative level of the maximum burned areas for different classes of fire hazard according to weather conditions is presented. These studies are necessary to justify the level of forest protection for fire seasons of different severity, which is characterized by the number of days with III-V classes of fire hazard according to weather conditions. The maximum burned area of forest fires calculated for long-term data could be also served as the basis for assessing the effectiveness of forest protection.