Home – Home – Jornals – Contemporary Problems of Ecology 2005 number 1

Methodical problems of analysis of influence of the chemical atmosphere pollution due to burning casing-head gas in flares installed in the territory of petroleum and gas deposits on boreal forests using geoinformation technologies and remote probing data are described. The landscape structure of petroleum extraction territories of the southern part of West Siberia based on the treatment of space images of middle resolution obtained from the apparatus Resource-01 is estimated. The pollution zones were determined by means of modelling the scattering of the polluting agents in the atmosphere using standardized scattering models. Relative areas of polluted landscape individuals depending on the change of petroleum extraction volume were estimated.

Biogeochemical cycles of Ba, Mn, Cu, Ni and Zn are studied in birch stands situated at various distances from the source of technogenius discharges. It is demonstrated that a 10-year long period of functioning of the hydroelectric power station-1 has not told on the reserves of heavy metals in basic blocks of forest ecosystems and on the flows connecting them. The C balance in birch stands points to their satisfactory ecological condition and capacity of performing their biospheric and environment-forming functions.

For a model description of processes of formation of liquid and solid surface outflows, experimental data collected as a result of multiannual systematized over seven classes of high-zone forest type complexes were used. The carried out studies have demonstrated that the projective cover characterizing both tree stands (composition, completeness, age) and the proportion of living surface cover may be used as the key information variable. A system of simple regression models describing the dimensions of liquid and solid outflows depending on the projective cover unified for all high-zone complexes has been constructed.

Data on the fraction structure of phytomass of forest swamps in West Siberia are presented and discussed in association with accumulation of organic carbon. Two mutually replenishing variants of calculating the phytomass and carbon are proposed, based on the materials of the State performed estimation of the forest reserves of administrative territories and of direct stationary experiments in various ecosystems of forest swamps of the southern taiga subzone. For the first time, materials are presented on biological productivity of a large group of swamp birch stands dominating, at the same level as the pine stand formation, in the system of forest swamp complexes of the region. A conclusion is drawn that a differentiated estimation of catching and retention of organic carbon by the phytomass of forest swamps considerably extend the modern ideas of the deposing role of hydromorphous ecosystems of the West Siberian plain and their partici

It is demonstrated that in the fir tree increment in the northern taiga , suppressed and dominant plants of Siberian pine and Scots spruce react in different manner to weather conditions. It is established that in July, the indices of radial increment in all fir and spruce trees correlate positively with precipitations independently of their position in the tree stand. A contrary reaction of radial increment of dominant and suppressed trees was observed in fir to changes of precipitations in June and temperature in July, and in spruce to changes of July temperature. The factor on which the radial increment depends stronger than on weather factors in all fir and spruce trees is the deficit of substance and energy resources.

Reconstruction of the summer (June-July) and mean annual air temperature for the last 2000 years for two subarctic regions of Siberia - north-east Yakutia and the eastern part of the Taimyr peninsula - has been carried out. According to the reconstruction data, synchronous and asynchronous extreme warming and cooling-off periods within the period studied were found. The performed analysis of long-term measurements of climatic conditions has demonstrated that during 2000 years, there have been clear-cut climatic variations in the annual ring chronology of global character (middle age accumulation, short glacial period, modern warming). It has been shown that in the East Taimyr and North-East Yakutia the summer air temperature in the XX century, as compared to XIX century, increased on the average by 0.5-0.6 

For the purpose of search for new characteristics of annual rings, a mechod of measurement of CO₂emitted by a ring is proposed. The object of study were annual rings of Scots pine (Pinus silvestris L.) and Siberian spruce (Picea obovata Ldb). The carbon dioxide concentration was measured by a laser opticoacoustical gas an

Analysis of the modern state of cultivated forest reserves of the southern taiga subzone in the Krasnoyarsk region is given, and an algorithm of detachment of forest-growing types in areas of cultivated forests is proposed using a geoinformation system for a more substantiated choice of forest vegetation species in artificial reforestation.

The considerable change of climatic structure of regions of Siberia that started by the middle of the last century and is observed during the last years has inevitably to be reflected on the time course of the forest-steppe contact zone. Estimation of intensity of this process will make it possible to judge about the greatness of climatic changes. In order to clear up the main factors determining the time course of changes of the forest-steppe border, dendrochronological studies were carried out in one of sites of the forest-steppe zone in the territory of West Transbaikalian region. These studies demonstrated that the time course of the border changes in the region studied is to a certain degree associated with the changes of hydrothermal regime.

Changes of maximal intensity of photosynthesis of Scots pine (Pinus silvestris L.) and Siberian larch (Larix sibirica Ledeb.) depending on the radiation intensity, air and soil temperature, air humidity and reserves of accessible soil humidity of the upper half-meter layer were studied. It is shown that optimal ranges within whose limits the highest values of photosynthetic activity are realized change both during the vegetation period and in years of various heat and moisture-providing levels. The species specificity of ranges is analyzed taking into account the peculiarities of water regime and components of carbon dioxide exchange - the true photosynthesis and respiratory activity of each species. The analysis of assimilation activity in "abnormal" season makes it possible to specify the notions of peculiarities of realization of the photosynthetic potential of conifers under natural conditions.

During several vegetation seasons, the dependence of the maximal diurn

Areas of unreforestated fillings in Siberia increase every year. The reserve of surface burning materials in them is often as large as 120 ton/ha. Therein, 70 % of fires arise in these areas, which exerts a strong influence on the carbon balance in the ecosystem. Our studies were carried out in continuous fellings in coniferous forests of the lower reaches of the Angara, Yenisei range and East Sayan. Estimation of biomass burning has demonstrated that in classes III - IV of fire hazard by weather conditions, fire emissions amounted to 20-28 ton/ha, in class V it was 30-35 ton/ha. Carbon "conservation" therein amounted to 15-35 ton/ha. The rate of the post-fire deposition of carbon depends on the success of reforestation which is determined by the further type of felling overgrowing and the availability of seed sources.

It is demonstrated that the basic components of volatile emanations of coniferous forests actively participating in the substance circulation are terpenoid compounds. Reserves of these compounds have been seudied in stands, air and soil of pinr forests, The amount of ether oil is on the average in phytocenoses 200, including in the leaf-fall and forest litter 23 kg/ha. Emission of terpenoids in pine forests, depending on the age and other causes, varies within the limits of 36-86 kg/ha. Together with the emission of these substances and other sources, the total annual mass of soil terpenoids is estimated at 65-80 kg/ha, which amounts to 2-3 % of the mass of humus substances.

Adaptation of the larch Larix gmelinii at the levels of a single tree, a stand, and the species in the northern taiga of Central Siberia is considered. It is established that the species is characterized by a low fire resistance of single trees and stands and the species as a whole has a high fire resistance, thanks to which it retains its area. It is demonstrated that at early stages of post-fire successions the larch displays the properties of pyrogenic explerent, wherein r-selection takes place. When the forest restitution period is mainly completed, the explerent state is replaced by the patient one including all the properties characteristic of K-selection. The notion of adaptive reactions to the pyrogenic factor at a single tree, plantation and forest stand levels have been united into a whole adaptive complex, which is the determinant condition of the species viability.

Experimental data on the density of sods of separate sphagnum moss species on an oligotrophic swamp are presented. Fraction analysis of moss stalks by weight and morphological properties is carried out. The contribution of each fraction to the biomass production is studied. Linear and weight parameters of the photosynthesizing surface of separate moss species, the productivity of dominant moss species on swamps of oligotrophic type are estimated.

Changes of the species composition and structure of the living surface cover under the influence of controlled burning in the pine stand of shrub-lichen-green moss subzone of middle taiga of Central Siberia were studied. Destruction of the moss-lichen cover and degradation of mosses and lichens take place already in the first year after a fire. The direction of the initial stage of pyrogenic succession is determined by the depth of burning of the litter and by the degree of damage of the surface cover. After fires of weak intensity, the cover mosaicism is decreased due to magnification of small contours, and after strong ones, formation of a small-contour mosaicism is observed. In this case, the leading role in the cover structurization is played by explerent or early succession species. Thanks to the pyrofitness of the pine and manifoldity of the formed pyroecological regimes, the species diversity of the grass-shrub storey is conserved, and it is only the abundance and the projective cover of plant species that change.

The impact of low fires of various intensity on the main physical, physicochemical, chemical and biological properties of soils in middle-taiga pine stands is considered. The influence of fires on the microflora and invertebrate complexes of sandy podzols and on the processes of post-fire transformation of the soil biota is studied.

The applicability of the surveying Landsat to an