Vol 11, No 1 (2018)

The understanding of relationships between the plants and environmental variables is important for ecological restoration. The objective of this research was to investigate the controlling soil factor in plant growth and salt tolerance of leguminous plant Alhagi sparsifolia Shap. (A. sparsifolia) in a saline desert ecosystem of western China. Results showed that coverage of A. sparsifolia was positively linked to soil total K. A. sparsifolia accumulated the toxic Na⁺ in either roots or stems and thus reduced their allocation in the leaves to adapt the salt stress. The most important factor that determined Na⁺ uptake of A. sparsifolia was soil total K content, which suggests that total K can alleviate toxic Na⁺ accumulation in A. sparsifolia. In addition, there was a significant negative correlation among toxic Cl⁻ concentration in A. sparsifolia, soil total K and pH. Overall, soil total K accounted for 18.2% of plant growth and salt tolerance of A. sparsifolia, followed by soil pH 13.1%, and soil total P 11.6%. In order to restore A. sparsifolia in the degraded desert ecosystems on salinized soil, first we need to consider the effects of soil total K, and then synergistically consider the soil pH and total P.

We have investigated changes in the complex of biochemical parameters reflecting the disturbance of the homeostatic state and the activity of the adaptive reactions in Pinus sylvestris L. under the conditions of technogenic pollution. Disorders of the physiological state of trees growing under the effect of the excessive accumulation of pollutant elements result in changes in a number of parameters: a decrease in the ratio of protein and nonprotein nitrogen fractions in the needles by 52%; a decrease in the total phosphorus and its acid-soluble fraction by 40 and 63%, respectively; a decrease in carbon concentration by 31%; and a decrease in the amount of chlorophyll a, chlorophyll b, and carotenoids based on the weight of one needle by 23, 40, and 42%, respectively. The activation of protective reactions of pine is proven by an increase in the amount of ascorbic acid in needles by 48%; in the amount of water-soluble phenolic compounds by 29%; in the ratio of Chl. a/Chl. b by 35%; in the ratio of green pigments to yellow by 40%; and in the level of water- and alcohol-soluble proteins 40 and 30%, respectively. The highest activity of biochemical protection components was recorded in trees growing near the Shelekhovsky industrial center, the emissions of which contain a large amount of fluorides and polycyclic aromatic hydrocarbons (PAHs).

This study evaluates dynamic changes in levels of Hsp70s and products of lipid peroxidation due to hyperthermia in the laboratory-raised freshwater pulmonate mollusk Stagnicola corvus (Gmelin, 1791). It is concluded that acute hyperthermia in S. corvus leads to the activation of nonspecific mechanisms of stress adaptation, which is manifested in an elevated Hsp70s level in the beginning of exposure, followed by a reduction in protein concentration, and the further preservation of the Hsp70 at a level exceeding the constitutive forms. At the same time, the level of LPO products tends to decrease, which indicates strengthening of the antioxidant defense processes in response to stress.

The distribution of zooplankton has been studied in a waterbody whose entire area is occupied by phytocenoses with the dominance of plants of different ecological groups. It is shown that, in the phytocoenosis of the submerged hydrophyte Elodea canadensis, zooplankton is involved in the classical grazing trophic web. The zooplankton community in this phytocoenosis is mainly made up by algaephagous species. In the habitats occupied by emergent plant Carex riparia, zooplankton is more closely associated with the components of the “microbial loop,” where the most abundant groups are predators and bacterio-detritophagous species.

The status of the environment in the development area of oil and gas condensate fields (OGCFs) in the north of Western Siberia (the Yamalo-Nenets autonomous okrug (YNAO)) has been evaluated on the basis of long-term investigations (1993–2016). The content of oil hydrocarbons, polycyclic aromatic hydrocarbons, and heavy metals (Cu, Zn, Fe, Pb, Cd, Ni, Co, Cr, Ba, Cd, and Mn) is determined in soils, natural waters, bottom sediments, and indicator plants (Larix sibirica, Betula nana, Salix lanata, Ledum decumbens, Vaccinium vitis-idaea, Vaccinium uliginosum, and Cladonia alpestris). Species pleiads, corresponding to the ecological conditions of habitats and the intensity of technogenic impact, are specified with the use of the coefficients of interspecies conjugation of plants. A complex of indicators of the transformation of natural complexes under the effect of oil and gas extraction is proposed.

The phenomenon of trunk twisting in Pinus sylvestris L. and Picea obovata Ldb. during a vegetation period has been revealed and described by direct measurements. The frequency of this phenomenon, magnitude, and direction of twists and their 2-year dynamics have been studied on five sample plots located in different forest-growing conditions. The average rotation angle is 0.2°–0.5°, while its maximum values reach 1.3°–1.7°. These characteristics depend on forest type and weather conditions. Next year more, than half of the trees change their twisting direction to the opposite one, whereas 8–19% of pine trees keep it unchanged. Based on an analysis of our results and the data of other authors, a qualitative model of morphogenetic processes has been proposed to explain the mechanism of this phenomenon.