Home – Home – Jornals – Contemporary Problems of Ecology 2012 number 2

Polymorphism of the main morphological characteristics used in species diagnostics was studied at the northern limits of Siberian spruce (Picea obovata Ledeb.) habitation. The analysis of population structure was performed. The results were compared with the characteristics of spruces from the central regions of the area. The data obtained permit making the conclusions about population structure and a pattern of Siberian spruce variation within the area.

Reconstruction of the dynаmics of the range of Artemisia genus was carried out with the help of palynoareological method on the basis of the data of 97 pollen diagrams from the territory of West Siberia and the Altay-Sayan mountainous region over the millennial time sections since the Late Glacial time till the present time. It was revealed that the maximal spread of the absinthe steppe communities (probably of the cryoarid pattern) occurred at the territory under examination 13-10 thousand years ago. After the time point of 9 thousand years ago, a fundamental change of the landscapes of West Siberia occurred, which resulted in the decomposition of previously continuous absinthe steppe cover into separate blocks. Since 8 thousand years ago, the absinthe steppe communities of modern appearance occupied the zone of modern steppe and forest-steppe of West Siberia and Northern Kazakhstan, while over the taiga zone the absinthe communities were spread occasionally under the extrazonal conditions and as the pioneering plant groupings on affected soil. Since the time point of 4 thousand years ago till the present time, the northern boundary of the steppe zone underwent pulsing shifts to the north and back, and also broadening and narrowing of isolated steppe islands took place. At present, we observe an increase in the role of absinthe plants in the tundra zone of West Siberia and in the Altay mountains.

Morphological and anatomic features of underground bodies of 12 species of Magnoliophyta plants growing in the tundra of the Yamal peninsula are revealed. The structural attributes of roots and rhizomes used for their identification and important for understanding of adaptation of species to extreme conditions are determined.

Tree plants in ten types of forest-tundra virgin spruce phytocenoses were studied for the purpose of revealing the factors that determine their vital state.

Comparative characterization of the response physiognomical reactions (classes of chloroses, necroses and crown scarcity) of woody plants in the industrial cities Ust-Kamenogorsk and Zyryanovsk is given. The regularities were revealed in the changes of the functional state of green plantations depending on the degree of greenery planting, species composition and structure of plantations, sanitary and hygienic care, the amount of poolutants entering the atmosphere, and city scale.

The concept of equivalence classes and factor-sets, known from ensemble theory, is introduced in application to the theory and practice of botanical investigations. The properties of taxonomic, typological and gradient factor-sets and their connection with the comparative floristic and phytoindicative analysis are considered. Upsized groups of regimes for 10 ecological factors of D. N. Tsyganov's phytoindicative scales are proposed. Computer realization of processing the data on plant cover with the help of factor-sets in the integrated botanical information information system IBIS is described.

Features of progressive successions in the landscapes with different levels of anthropogenic transformation (the southeast of Belarus) are considered. The comparative analysis of succession characteristics in weakly and strongly disturbed landscapes is performed. It is established that succession in strongly disturbed landscape differs by the slower speed of changes of the vegetation and essential delay at early stages (including initial stages). Strongly disturbed landscapes are characterized by the high degree of synanthropization and a significant level of invasion at all the stages of succession.

Changes in the content of triterpene alcohols of dammaran series in the leaves of Betula pendula Roth along the zonal-climatic trasect from the northern to the southern limit of the range of this species in the Trans-Ural region was studied for the first time. It was shown that the populations from the northern and southern regions differ in the amount of triterpenes. A connection between the content of triterpene alcohols in the leaves of Betula pendula with climatic parameters was revealed. In this situation, the amplitude of intra-population variability of triterpene content is essentially lower than that of inter-population variability, which is the evidence of the promising character of population selection on the basis of this biochemical index.

Approaches to the use of bioindication methods for estimation of the ecological conditions of water ecosystems under pollution with hydrocarbons are discussed. The consequences of the transboundary pollution of the Amur River ecosystems with benzene derivatives after a technogenic accident at a petroleum chemical plant in China are considered for the example of responses of microbic complexes and the accumulation of toxic substances in fish.

Forest litter is the most significant component of forest biogeocoenosis for the studies of the behavior of chemical elements and artifical radionuclides during forest fire events. The ubiquitous distribution of forest litter, active biogeochemical processes that occur in it due to permanently incoming organic matter, high depositing properties with respect to chemical components preciрitated from the atmosphere align forest litter as the natural objects playing an exclusive role of biogeochemical barrier at the routes of element migration in forest ecosystems. Investigation of the distribution of chemical elements in forest litter and the degree of its burning out during forest fires allow us to distinguish a group of elements that migrate from the sites of fire and to determine the degree of their carry-over quantitatively.

Stable nitrogen isotopes (δ ¹⁵N) were measured in the organic matter (OM) of the thallii of vagrant lichen Xanthoparmelia camtschadalis collected across the altitudinal gradient, from 1550 to 3250 m a.s.l. in the steppe and highland meadows in the Khangai Plateau, Mongolia. On the regional scale (all sites), a correlation between δ ¹⁵N values and the altitude range is absent. However, in the steppes at low and medium altitudes (Eastern Khangai) OM is depleted in ¹⁵N with increasing altitude from 1550 to 2300 m a.s.l. Also in the highland meadows of Central Khangai, OM is depleted in ¹⁵N with increasing altitude. According to our own data, the results obtained at a local scale do not always correspond to those on the regional scale.

Data on beryllium content in the ash and air-dry mass of the organs of Pinus sylvestris were obtained. The certain regularity in the distribution of beryllium in needles and branched over years was revealed. It was established that beryllium is an element of strong accumulation for Pinus sylvestris under the conditions of the region under investigation, but its role in the general cycle of matter is of minor importance.

The ability of 128 plant species from 44 families and 28 genera of the Far East flora to accumulate lead was investigated. A substantial range of deviation was revealed for lead content in the assimilative organs of plants: 0,81-25,67 mg/kg of the dry matter. The major regularities of metal accumulation in the plants of different  systematic taxons and biomorphological groups were established. Plants were grouped on the basis of the intensity of lead accumulation, and metal concentrating species were determined. Species promising for phytoindication and phytoremediation of the urban environment are recommended.

Results of monitoring studies of mine dumps in the area of uranium deposit in South Yakutia are presented. The complex application of biological, biochemical and geochemical methods allowed us to reveal mass transfer of radionuclides and heavy metals in the system radioactive dumps - soil - plant and their influence on seed progeny of Duschekia fruticosa (Rupr) Pouzar.

Informaiton about changes in the state of plants under the action of waste materials from oil and gas well-boring (WB) and about the transfer of toxic elements from soil to vegetative organs is presented. It was established that the growth and productivity of plants are stimulated if the concentration of WB in oligotrophic substrates is up to 20 %, without the transfer of individual elements into vegetative organs.