Home – Home – Jornals – Siberian Journal of Forest Science 2018 number 6

The results of complex forest-ecological studies at the Khan-Khukhii Mountain Ridge in the territory of National Natural Park Khan-Khuhii-Khyargas-Nuur, Western Mongolia are presented. The forests at the Khan-Khukhii Mountain Ridge are isolated from the north by the desert, and from the other sides - by dry steppes. The location of the stands makes it possible to study climatic, geomorphological and economic factors, affecting forest formations along the border of forest distribution. Five sample plots in accordance with the variety of forest vegetation and geomorphological locations were established during the field surveys. Sample plots were placed at the lower forest boundary in the old-growth larch sparse stand experiencing the greatest pasture load, and in the herbaceous larch stand with zoogenic inhibition of undergrowth and fragments of selective felling of the lower part of the northern slope. Larch forests of green moss-red bilberry type with the participation of the Siberian stone pine are characteristic of the upper part of the slopes. The Siberian stone pine stand with dead ground cover is bordered by watersheds and a steppe southern slope and a herbaceous larch stand in the north. An intrazonal object was categorized as yernik (dwarf birch) on permafrost grounds. The geomorphological affiliation of the Siberian stone pine and larch formations to elevations above the sea level and slope exposition is shown. The zoogenic factors determining silvicultural processes limit forest restoration and lead to the formation of a savannah type of vegetation. Under adverse climatic conditions, primary pests of larch needles and root pathogens are detected. Forest logging leads to the growth of grass cover and movement of livestock into the forest zone, followed by the cessation of forest restoration. In the forests of the Khan-Khukhii Mountain Ridge there are no signs of fires (no cinder and fire scars on tree stems), which indicates a long pasture load and the impossibility of accumulation of combustible material. The results of the study made it possible to recommend the directions for silvicultural operations on the territory of the National Natural Park Khan-Khukhii-Khyargas-Nuur. First of all, it is necessary to identify factors of the curtain and highly dense forest regeneration on the border between the forest and steppe. If there is a continuing intensive pasture load, forest compartments will remain within the present boundaries or will be reduced. The impact of global climate change on the current distribution of forests has not been revealed.

The State Forest Inventory (SFI) has been performed in Russia since 2007. The methodology of SFI includes stratification of the stands and limitation of the area of sample plots (SP). The projecting of the SFI is based mainly on the data of the forest planning (FP), which was applied earlier. The differences in the evaluation of timber stock based on the results of SFI and FP and the SFI methodology are a subject of discussion. The background statistics of SFI and FP data of Uvatsky forestry district in Tyumen oblast are considered. A feature characteristic of evaluating timber stocks by SFI and FP is a marked asymmetry of their distribution, which makes parametric estimation of the stock accuracy ineffective in both cases. It is shown that the limitation of the area of SFI SP did not influence the final stock evaluation. An attempt was made to estimate the error of timber stock evaluation using non-parametric statistics of resampling, generating a set of pseudo-samples. The use of resampling of SFI SP and FP forest inventory surveys at SFI points made it possible to determine the dependence of the accuracy on the number of SP and the value of the intra- forest compartment variation of timber stock, which did not depend on the number of SP and turned out to be much higher than that provided in the SFI projecting methodology. Generation of pseudo-samples of SP on the forest map considering the obtained values of intra- compartment variation allowed to determine the expected dynamics of the accuracy of evaluation of timber stock with increasing SP. Underestimation of the intra- compartment variation of timber stocks partly explains the large difference in the evaluation of timber stocks using SFI and FP data. The low influence of the applied stratification of the stands on the accuracy of SFI results is shown.

Information on thinned tree stumps was included in a stand reconstruction technique to test possible improvements in the estimates of stand variables (aboveground biomass, total stem volume, stem volume growth and stand density). Thirty sample trees and one hundred and sixty-eight stumps of the Sakhalin fir Abies sachalinensis (F. Schmidt) Mast., the Ezo spruce Picea jezoensis (Siebold & Zucc.) Carrière, and Glehn’s spruce Picea glehnii (F. Schmidt) Mast., were collected in six stands of pure tree species within the Hitsujigaoka Experimental Forest in Hokkaido, Japan. Stem analysis data and census data both gathered in 2013 from six stands were used to estimate stand variables in the past. Then, the stand variables were estimated by the stand reconstruction technique, with and without the stump information and subsequently compared in terms of prediction accuracy. In other words, the reconstructed values were statistically compared with the observed values obtained from censuses between 1988 and 2013. The results showed that the accuracy of the estimated variables can be improved by alleviating underestimation after adding old stumps. Without adding data on the stumps, the percentage error of the estimates of the stand variables varied within ± 20 % of the observed values. By including the stumps, the percentage error of the estimates of the same stand variables generally fell within ± 15 % for the years after 1997. The 95 % confidence intervals of the estimated means by the bootstrap method suggested that adding stumps does not always improve the prediction in stand density; but generally, improves the predictions on aboveground biomass, stem volume and stem volume growth. Overall, dramatic changes in the aboveground biomass and stand density through thinning operations were reproduced better, although the amount of improvement is sometimes minimal, by incorporating information on the stumps for all 3 species examined.

The results of long-term studies of the role of the pyrogenic factor in the dynamics of forest ecosystems in the mountain Cis-Baikal region are considered. The consequences of surface fires in the full range of their intensity, from weak to extremely strong, are analyzed. The damage characteristics in pine and larch stands, differentiated by the types and degrees of fire impact, were obtained: burning and drying on stems, death of crowns with weakening the viability of trees, anomalous thinning. Fire scars on the surface of the tree stems, as an indicator of the degree of fire impact, serves as an external diagnostic sign of the post-fire condition of specific individuals. The higher on the stem fire scars are, the greater part of the tree was exposed to harmful thermal effects. But due to the variability in growth expressed in forest stands, trees differ in their reaction to such impacts. Young Scots pine Pinus sylvestris L. and the Siberian larch Larix sibirica Ledeb. tree stands are largely damaged and, as a rule, die after the exposure to medium-intensity fires, and at the age of 10-15 years even die after low intensity surface fires. The most vulnerable to fires are tree species with thin bark, such as Siberian stone pine Pinus sibirica Du Tour, Siberian spruce Picea obovata Ledeb., Siberian fir Abies sibirica Ledeb. and flat-leaved birch Betula platyphylla Sukacz. It is noted that 100-120-year-old Siberian stone pine stands are largely damaged by low-intensity surface fires, and are completely damaged after intense surface fires. The quantitative indices of liquid and solid surface runoff at the burnings are given. Mathematical models for the formation of liquid surface runoff and associated erosion of soils on burned areas are proposed, depending on the main factors affecting the development of these processes. The pyrogenic destruction of forest ecosystems inevitably results in the degradation of mountain soils, the restoration of which after surface fires takes many decades.

One of the directions of progressive plant successions on the dumps of daylighting grounds is the artificial formation of forest stands. Pine and sea buckthorn stands are planted in the Kuzbas in the areas of forest reclamation, while birch forests appear as a result of natural overgrowing. As the model object, the Kedrovsky coal mine was selected, located in the subzone of the northern forest-steppe of the Kuznetsk basin. The dumps of the Kedrovskiy coal mine were used 25-35 years ago, and are now characterized by a wide range of tree stands, varying, first of all, in density and closeness of crowns. During forest inventory and geobotanical studies, a description of the structure of the communities formed were completed and the species composition of the main and undergrowth tree species, the nature of reforestation under the cover of the first generation of trees and the ecological and cenotic structure of the herbaceous populations were studied. It was established that on the dumps Scots pine trees are stable and of one tree species stands with the occasional presence of other tree species: thosewith high crown density developed ondead soil cover, while the sparse stands were characterized bywell-formed undergrowth. In birch forests, on the contrary, the tree species composition is enriched, a stable undergrowth is developing. In pine and birch stands, the forest species are increasing, the share of ruderal vegetation is considerably reduced, the variety of species of legumes family grows, which, along with the successful regeneration of trees and shrubs, is indicative of the forest trend of succession. In the sea buckthorn stands a degradation is noted; due to repeating fires, reforestation is poorly expressed, the predominance of ruderal species is observed in the herbaceous layer. It has been established that the sea buckthorn inhibits the course of progressive forest successions.

The study was performed on 25-year-old grafted progeny of young and mature generative trees of the Siberian stone pine Pinus sibirica Du Tour. The Siberian stone pine forests in the south of Western Siberia, grafted on a young tree stock, the influence of the age of the mother tree on the vegetative and generative crown structure of the grafters and the degree of epigenetic inheritance of age- specific features of morphogenesis were studied. The analysis of the results showed that the differences between the grafting of young and mature trees according to the generative structure of the crown are expressed by an order less than in the vegetative structure. Ontogenetically, older grafts of mature trees with smaller crown sizes were superior to those of young trees due to the efficiency of generative processes in terms of the unit volume of the crown. According to the level of growth, which was estimated by the size of the stem and crown, they were significantly inferior to the grafts of young trees. The most interesting result is a noticeable difference in branching between the two groups of trees. The grafts of young trees were branched in accord with older axesformed mainly from the buds of regular renewal, due to which the total number of shoots in the crown increased substantially and, as a result, its density increased threefold. The share of latent buds in the grafts of mature trees increased substantially, and branching was developing mainly due to the first and second branching axes; as a result, the crowns of the grafting of mature trees visually resembled separate branches from the upper parts of the crown of ontogenetically old trees The results obtained imply that in the vegetative progeny of trees of a different ontogenetic state, the growth potential is primarily epigenetically inherited. Qualitative transformations in morphogenesis, including sexual reproduction, should be considered as secondary phenomena, as markers of epigenetic inheritance of growth potential.

The results of the survey of the Korean pine Pinus koraiensis Siebold & Zucc. forest crops in the south of the Far East are presented. Reforestation in this region began in the 1950s and 1960sTherefore, most of the studies were carried out in the young stands. Our studies were conducted on the territory of Ussuriysky and Kurortny Forestry Districts of Primorsky Krai, where 25 temporary sample plots were located. On sample plots, the forest crop indicators were within the following ranges: average DBH 1.0-14.4 cm; average height 1.8-13.7 m; average age 14-42 years. The key role of the inadequacy (in some cases, absence) of silvicultural care for under-canopy Korean pine forest crops in reducing their growth rates is shown. The annual increment of the forest crops in the height and DBH is largely determined by the density of upper stand canopy (R² = 0.6-0.8), which, after first care logging (reconstructive cuttings), should containno more than 15 m²/ha of the upper stand canopy area. Annual DBH increments were analyzed for the Korean pine trees in different sample plots. The trends of a sharp decrease in the width of annual rings in the compartments without silvicultural care are revealed. The first care logging should be made not later than in 15 years after planting forest crops, when their requirement for photosynthetic active radiation (FAR) sharply increases. Forest crops created in open space in the first years had an increase in DBH up to 1 cm per year, which in the absence of clearing decreased twice. After the creation of under-canopy Korean pine monocrops in Primorsky Krai, multi-tree species stands are naturally formed; therefore, simultaneous use of other tree species for planting is not recommended.

The study is focused on the influence of ambient temperature on biomechanical properties of tissues in the treesgrowing in the conditions of protected and open grounds. The investigations were carried out on 11 plant species growing in the greenhouse of Donetsk Botanical Gardens and 11 tree species growing in open grounds in the conditions of the city of Donetsk. The experiment included two series of trials: 1) calculating the Modulus of Rupture (MOR) of woody tissue for species from the fig Ficus L. genus at +23 ºС; 2) finding temperature dependence of the Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) for the Illawarra flame tree Brachychiton acerifolius A. Cunn. ex G. Don Macarthur et C. Moore and ceiba Ceiba pentandra (L.) Gaertn., and calculating the same dependences for 11 open ground plants. The values of MOR for 7 greenhouse species averaged 4.9 ± 0.7 МН/m², i.e. circa 20 times lower than in natural environments. Such species as Haroni fig Ficus vallis-choudae Delile and banyan fig Ficus benghalensis var. krishnae (C. DC.) had the lowest MOR values. The study of the influence of low temperatures showed that in the sample pretreated by -23 °C freezing and then heating, MOE dropped simultaneously with slowing of the temperature shift. The altering of MOE is of a stepwise character. The common temperature breakpoint for all the curves is T = 0 °C, i. e. freezing point. According to the values of MOE and MOR, the most resistant species are rubber fig Ficus elastica Roxb. ex Hornem. and Benjamin fig Ficus benjamina L. (for greenhouses), and northern red oak Quercus rubra L., common oak Quercus robur L., and silver birch Betula pendula Roth (for open grounds). The studies allow us to recommend temporary outdoor tub-gardening in summertime for greenhouse trees with proper for each plant shading. Open ground trees should be protected from irreversible trunk bending and breakage preventing or reducing exposure of the lower part of their trunks to light using protective fiber wraps or special cases.

The central Anatolian region of Turkey is exposed to increasing temperatures and severe drought stress. Due to aridity and desertification brought about by global warming, climate change and overutilization, plant species in these regions are under the risk of extinction. Thus, plant species have to adapt to these harsh environmental conditions of extremely high temperatures and low precipitation. In this study, gas exchange and water potentials of the Arabian almond tree Amygdalus arabica Olivier (C₃-photosynthesis) and four-winged saltbush Atriplex canescens (Pursh) Nutt. (C₄-photosynthesis), two drought-tolerant woody species planted previously in an effort to reduce desertification at Karapınar, Konya, and Central Anatolian Region, were periodically measured from May until September under field conditions. Net photosynthesis and transpiration rates, mid-day water potential and water use efficiency were determined throughout the vegetation period in 2015. Maximum net photosynthetic rates were 12.4 μmol m^-2 s^-1 in the Arabian almond tree and 29.7 μmol m^-2 s^-1 in four-winged saltbush, measured in July and September, respectively. Also, the highest transpiration rates were 4.8 mmol m^-2 s^-1 in the Arabian almond tree and 7.1 mmol m^-2 s^-1 in four-winged saltbush. Maximum water use efficiency values were measured in June in both species, which made up 5.7 and 7.7 mmol CO₂ mol^-1 H₂O for the Arabian almond tree and four-winged saltbush, respectively. Lowest midday water potentials for both species were recorded in August. The results indicate that both species have the ability to tolerate drought stress in the region, though due to its C₄ nature of photosynthesis, the four-winged saltbush might overcome those stresses more efficiently than the Arabian almond tree in arid and barren areas .

Morphometric quantitative (length and width of female catkins, length and width of birch-capsules) and functional parameters (germination and germination power of birch-capsules, length of shoots) of the female reproductive sphere of drooping birch Betula pendula Roth. trees growing in the zone of technogenic emissions’ impact in the city of Krasnoyarsk have been studied. The studies were carried out on permanent sample plots established in birch stands growing in the southeastern, northern and northeastern environments of the city of Krasnoyarsk. Reproductive processes of drooping birch in the Krasnoyarsk forest-steppe were studied for the first time. The studies have shown that two-year periodicity of fruiting is characteristic of drooping birch trees of the Krasnoyarsk forest-steppe. The sizes of female catkins and birch-capsules vary depending on the genotypic characteristics of trees, the conditions of growth of the tree stand, also in different years of studies. With an increase in the degree of technogenic load, birch trees showed certain signs of a decrease in reproductive activity (a decrease in the morphometric parameters of female catkins and birch-capsules), as well as qualitative indicators (germination and germination power) of birch-capsules. It was revealed that the length of female catkins and the width of birch-capsules are negatively correlated with the content of fluorine in the foliage. The regression equations were calculated within the range of parameters: y = -0.0489 x + 2.8127 и y = -0.0346 x + 1.7732. The quality characteristics of birch-capsules (germination and germination power) were negatively correlated with the amount of settled dust on the lamines, as well as with the fluorine content in the leaf mass. At the same time, the maximum quality indicators were characterized by fruits harvested in background conditions. Functional signs of the female reproductive sphere of drooping birch are the diagnostic criteria for assessing the condition of trees, and can also be a direct indicator of the environmental conditions of growth.

Forest biomass is a key ecosystem trait and an important component of the global carbon cycle. Biomass modelling is performed in terms of forest stands and sample trees. However, all current studies of this subject are carried out, firstly, within limited ecoregions and secondly, without harmonizing in relation to fractional composition of the biomass. Models harmonized in accordance with fraction composition of biomass are widespread and are referred to as additive ones. Among them, two groups of models are distinguished: one is focused on the calculation of equations separately for each fraction, followed by their modification in accord with a special algorithm so that the total result of these equations is equal to the result of the common equation. The second procedure of equation harmonizing applies the opposite algorithm, according to which the common equation is calculated, which is divided into partial ones according to a special scheme, and their total is equal to the final result of the common equation. The database on biomass of 1035 spruce and fir trees growing in their Eurasian habitats developed by the author, is used as a basis for revealing differences between equal-sized trees of two genera in the structure of biomass, while ensuring the principle of consistency in the second of these options. A harmonized model allowing to compare the biomass structure of trees of two genera in terms of a continental approach is proposed for the first time. It has been revealed that total, aboveground and underground biomass of fir trees exceeds that of spruce by13, 11 and 20 % respectively. However, there are some differences between Abies and Picea genera in the ratio of aboveground and underground biomass in the total biomass and in the ratio of the crown and stem biomass in the aboveground biomass, while any differences between two genera are not in the ratio of needles and branches in the crown biomass and in the ratio of wood and bark in the total stem biomass. The proposed model of additive biomass structure makes it possible to calculate spruce and fir stand biomass in Eurasian forests when using ground forest survey data.

International conference on «Preparing Europe for invasion by the beetles emerald ash borer and bronze birch borer, two major tree-killing pests» took place on October 1-4 2018 at Vienna, Austria. Conference was organized by Austrian research and training center for forests (BFW, Vienna) and UK government Department for environment, food and rural affairs (Defra) within the EUPHRESCO project “Pest risk evaluation and pest management” (PREPSYS). 90 researches from 16 countries took part in the conference. 39 oral and 7 poster presentations were devoted to ecology, behavior, distribution, monitoring and control methods of emerald ash borer Agrilus planipennis - an Asian invasive pest of European and North American ash species and bronze birch borer Agrilus anxius - an American species, potential invader for Europe. Presented information was distributed among few section: (1) the threats: history and potential, (2) European initial perspectives, (3) monitoring and detection, (4) dispersal and range expansion, (5) managing infestations of invasive buprestids, (6) economic and social dimensions of managing pest invasions, (7) taking stock of multiple factors and next steps. The main interest of audience was concentrated on the situation with emerald ash borer in Russia. Secondary range of invader here occupies 13 administrative districts (oblasts): Yaroslavl, Tver, Smolensk, Kaluga, Moscow, Vladimir, Ryazan, Orel, Tula, Tambov, Voronezh, Lipetsk and Volgograd Districts. The pest is extremely close to the border with Belorussia and surely had crossed Ukrainian border. Conference participants pointed out the necessity of urgent consolidation of European countries efforts in preparing for dendrophagous buprestids invasion. This sad and dangerous event can hardly be avoided.