Pleiades Publishing Ltd

Changes in the abundance and taxonomic and trophic structure of necrophilous invertebrates inhabiting mixed forests have been studied in the area polluted with the emissions from the Middle Ural Copper Smelter. It has been shown that the abundance of most taxa decreases by factors of 2 to 80 along the pollution gradient, but the trophic structure and composition of major groups vary insignificantly. Changes in the necrophilous assemblage can be caused by either direct (toxic) action of industrial pollutants or their indirect effect exerted through modification of habitats.

The body size structure of carabid communities has been analyzed based on the 2009 and 2013 collections (with the use of pitfall traps) performed at 10 sites of a spruce–fir forest along the gradient of pollution with emissions from the Middle Ural Copper Smelter. A reduction in the unweighted mean body size of carabid individuals has been shown, as well as the heterogeneity of body sizes in the community (Gini coefficient) of the extremely polluted territory. It has been revealed that the weighted mean body size of individuals and the Lorentz asymmetry coefficient are not dependent on the level of pollution. Differences between the communities of carabids in the background and polluted territories are associated with the smaller number of large-sized species, while the similarity is explained by the dominance of medium- and small-sized species at all sites. The high interannual variability has been observed in the ratio of size groups of the analyzed communities at the background and moderate levels of pollution.

Studies on the reproductive biology of seabirds on Talan and Umara islands in 1987–1999 showed that the diet of nestlings and reproductive success of the tufted puffin (Lunda cirrhata) and horned puffin (Fratercula corniculata) considerably varied in different colonies. This was determined by differences in the hydrologic characteristics of water areas and the state of food resources in Taui Bay (the northern Sea of Okhotsk). The reproductive success of tufted puffins was higher on Umara Island due to more favorable environmental conditions and relatively stable food resources in Odyan Bay. The parameters of reproductive success and the nestling diet in tufted and horned puffins from Talan Island differed considerably. The survival of nestlings was always higher in horned puffins, which was related to some characteristics of their feeding ecology.

Interfamilial variation in metal tolerance and radioresistance of seed progeny from F 1 plants was studied in the dandelion from cenopopulations growing over several decades in gradients of radioactive or chemical contamination. The progeny from the impact zone of the Eastern Ural Radioactive Trace (EURT) proved to be highly viable but had latent injuries that accounted for a high sensitivity to additional technogenic impact. In the F 1 generation from the zone of chemical contamination, high seed viability was combined with increased tolerance to additional impact of radiation and heavy metals. No significant differences between responses to challenge with habitual and new factors were revealed in samples from either zone.

The functional state of the indicator species, the Gray mussel Crenomytilus grayanus (Bivalvia), has been analyzed in five areas of Peter the Great Bay exposed to anthropogenic pollution. The following indices of the state of mussels have been used: molecular biomarkers of energy metabolism—Na+,K+-ATPase, Mg2+-ATPase, and total ATPase activity—as well as the level of lipid peroxidation (LPO) and glutathione concentration in the hepatopancreas, gills, and gonads of mussels. The activity of ATPases, LPO level, and glutathione concentration significantly change in mussels from polluted areas relative to those in mussels from a conventionally unpolluted area (a bay in the Far Eastern State Marine Reserve). The molecular biomarkers used in the study provide reliable information on animal metabolism in impact areas. With consideration of the data obtained, it is concluded that the state of mussels in polluted areas is impaired.

The type of diaspore dispersal may have a significant effect on the vulnerability of herbaceous plants to anthropogenic transformation of ecosystems. However, there is still no unified opinion on the relationship between the type of diaspore dispersal and the processes of extinction and colonization. Here, descriptions of vegetation performed in the zone of impact from the Middle Ural Copper Smelter in the periods of high and low emission levels (1995–1998 and 2014–2016, respectively) have been analyzed to test two hypotheses: (1) the type of diaspore dispersal has an effect on plant vulnerability, with the species whose diaspores are dispersed farther being less vulnerable to habitat transformation; and (2) irrespective of the type of dispersal, recolonization is less intense under high than under low pollution levels. It has been found that the species richness of all plant groups highly varies in space: it decreases sharply in the zone of heavy toxic loads, but localities with high species richness occur even under conditions of heavy pollution. With the increasing pollution level, the species diversity within plant groups on a mesoscale (hundreds of meters) decreases more strongly than that on a macroscale (kilometers). Species with different types of diaspore dispersal differ from each other both in sensitivity to pollution and in the capacity for recolonization after reduction of emissions, but the relationship between vulnerability and the distance of diaspore dispersal is ambiguous. High sensitivity to pollution and low recolonization capacity have been revealed in species characterized by either the lowest (autochores) or the highest dispersal distance (epi- and endozoochores), with anemochores being the least vulnerable. The diversity of most groups in the zone of heavy pollution has remained low over the past 20 years; some positive shifts have occurred in myrmecochores and typical anemochores, with the dynamics of the latter being independent of pollution level.