Home – Home – Jornals – Contemporary Problems of Ecology 2018 number 6

In deep stratified lakes the processes of growth and death rates of zooplankton populations result in uneven vertical distributions of live and dead organisms in a water column. The carcasses in the water are removed by process of sinking, and degradation due to microbial decomposition and detritivory and etc. In case of epilimnion maximum of zooplankton and when the degradation prevails over the sinking the downward flux of carcasses exponentially decays with depth. The vertical profile of dead organisms, demonstrating the decline in meta- and hypoliminon, can be fitted with the curve of numerical model, presented in this paper. The model approximation of the field data allow to determine non-predator mortality rate m and degradation rate D in relative terms ( m / v and D / v , v - sinking velocity) or absolute values (with defined v ). For the case of copepod population of Arctodiaptomus salinus in Lake Shira the calculated m and D (medians of 0.13 and 0.26 day-1, respectively) were in a good agreement with the literature data. The presented method also gives the advantage of using the depth depended sinking velocity v .

The work is directed on proceeding study of cyclicity of long-term (1980-2010) population dynamics in odonates in the lake Chany basin (the south of Western Siberia). Four sympatric species of the genus Sympetrum were investigated with using of spectral analysis method. The cycle spectra of population dynamics have been constructed for each species, and the basic parameters of these cycles (period, phase, power) are calculated. The special number cycles were found in each species. Interspecific distinctions amplified in the direction from high to low frequencies of the spectrum. In cases of similar cycles an interspecific distinction was shown in the ratio of cycle powers and/or phases: identical phases can indicate ability of species to increase their number synchronously with any of close species, different phases can indicate opportunity in small species to reach its number maximum against number minimum at numerous species. Comparison of sympatric species spectra of the genera Coenagrion and Sympetrum has led to the conclusion that the more similarity in environmental standards among species inside genus (as at Sympetrum ), the more specific the species frequency spectra. All species of the genus Sympetrum can synchronize their number fluctuations with 2-3 and 4-5-years’ fluctuations of the local climate. Also the specific synchronization with important nature-climatic rhythms was found at each species: at S. danаe - with 18-year rhythm of the lake Chany level and with 16-year of June temperatures; at S. flaveolum - with 24-year briknerovsky, with 8-year of rainfall and with 28-year of April and May temperatures; at S. vulgatum - with 40-42-year of the lake Chany level, with 12-year of rainfall and with 7-year of April and June temperatures; at S. sanguineum - with 7-year of April and June temperatures. Perhaps, in the long-term number fluctuations of species the adaptation mechanism of species to each other and to environment is concluded.

Changes in the quantitative characteristics and functioning of phytoplankton in Lake Bol’shie Shvakshty have been assessed. The changes are evoked by the introduction of herbivorous fishes into the lake and the resulting disturbance of ecological balance in the ecosystem and the shift of the lake into a hypertrophic state from a weakly eutrophic state. Human interference has caused the cyanobacteria density (abundance) and biomass values in the overall phytoplankton composition to strongly exceed (3.5 x 109 cells/L and above 68 μg/L chlorophyll-а, respectively) the threshold value for safe recreational use of water bodies (20 million cells/L and 10 μg/L chlorophyll-а) established by the World Health Organization (WHO). The lake can be assigned to the third level of hazard to human health within the classification proposed by the WHO, as the cyanobacteria density is higher than 100 million cells/L and chlorophyll-а content is higher than 50 μg/L. MC-producing Microcystis species were identified among the cyanobacteria that has propagated in the lake in recent years, and five microcystin variants, including the highly toxic MC-LR, have been detected in the water.

The paper provides an overview of leaf-mining insects complex damaging willows ( Salix spp.) and poplars ( Populus spp.) in Siberia. According to literature data and our observations, 50 leaf-mining insect species (i. e. 24 species from Lepidoptera, 15 Coleoptera, 6 Diptera and 5 Hymenoptera) feed on plants from these two genera in Siberia. Using an integrative approach combining field work, morphological and DNA barcoding analyses, we identified 32 leaf-mining insects from 14 regions across Siberia (i. e. 64 % of all species on Salicaceae in this part of Russia). Among them, 26 species, most often found in parks and botanical gardens, represented new faunistic records for several poorly explored regions of Siberia. We increased the list of Salicaceae-feeding leaf-mining insects in Tomsk Region, Altai Territory and the Republic of Tuva in more than two times and for the first time provided data on leaf-miners for the northwestern region - Khanty-Mansiysk Autonomous Okrug. The micromoth Phyllocnistis gracilistylella (Gracillariidae), recently described from Japan, is a new record to Russia from the south of Krasnoyarsk Territory, where it was found on a new host plant ( Salix carpea ). Eight leaf-mining insect species (i. e. 5 gracillariids Phyllocnistis labyrinthella, Ph. unipunctella, Phyllonorycter apparella, Ph. sagitella , Ph. populifoliella , 2 beetles Zeugophora scutellaris, Isochnus sequensi and one sawfly Heterarthrus ochropoda ) can outbreak on poplars, in urban plantations, botanical gardens and plant nurseries in Siberia, rarely in natural stands. Forty five species of 50 leaf-mining insects known to feed on willows and poplars in Siberia also occur in Central and Eastern Europe. The remaining five species ( Phyllocnistis gracilistylella, Phyllonorycter sibirica, Heterarthrus fasciatus, Tachyerges dauricus, Isochnus arcticus ) recorded in Asia only. The species richness of the family Gracillariidae, the most diverse on Salicaceae in Siberia, has 80 % of similarity to that of the European part of Russia and 71 % to the Russian Far East. We discuss the faunal proximity of these regions and highlight the importance of applying an integrative approach combining ecological, morphological and DNA barcoding analyses to explore and characterize the insect fauna of poorly studied regions of Asian part of Russia.

The effect of alcohol extract and essential oil from Juniрerus sabinа L. (Cupressaceae) on the survival and nutrition of the larvae Galleria mellonella L. (Pyralidae) was studied. It was found that the essential oil has insecticidal, antifeedant, deterrent and repellent properties. The loss of larvae with topical application of 0.2 мl of essential oil to the dorsal part (contact action) reaches 64.0 %. Feeding larvae with food treated with essential oil of J. sabinа (200 мl of essential oil per 1.5 grams of feed) is reduced by 2.1 times compared to the control. It is shown that larvae G. mellonella avoid feeding on the oil treated feed during 14 days, and actively move in the opposite direction from the treated feed when they are placed in Petri dishes. It has been established that vapors of essential oil suppress the development of larvae G. mellonella even when fed with untreated food - there is a lag in body weight and a delay molting in the next age. The essential oil of J. sabinа also exhibits moderate toxicity (20.0 %) when the larvae eat the treated food, i. e. possess intestinal action. The alcohol extract of J. sabinа at a concentration of 2.5 % of active substances (on dry residue) has a negligible (insignificant) effect on the loss of larvae in the case with treatment of feed (10.0 % contact action). With topical application to the dorsal part, the extract causes 20.0 % of insect death. Antifeedant and repellent properties against larvae alcohol extract of J. sabina did not show, however, a low level of deterrental activity, expressed in suppressing the formation and development of pupae of Galleria mellonella , was noted. Essential oil reduced the percentage of pupated larvae.

Each species besides of having the unique morphological pattern, also has a unique ecological and climatic niche and a geographical range. The study of ecological-climatic and geographic divergence can make significant contribution to understanding of the species genesis and its volume. The purpose of this paper was to compare the ecologo-climatical niches of related species Poa palustris L., P. nemoralis L. and populations, which combined the morphological features of both and treated here as hybridogenous species P. intricata Wien. in order to reveal their identity. The research allowed to specify the areas of these species. Using GIS methods and based on the points of presence their ecologo-climatical niches were revealed. Then, taking into account 6 independent bioclimatic characters, their potential ranges - areas where the climatic conditions are favorable for growth - were identified and ecologo-climatical niches compared. It was established that the ecologo-climatical niches of three species, generated by MaxEnt, showed their differences at a statistically significant level.

The distribution and phytocenotic association of Parthenocissus vitacea and Vinca minor on the territory of the Bryansk region was studied, the assessment of these distributions was performed on a grid basis. Vinca minor is registered in 19 cells on the territory of the region, which is 4.9 % of the total number of cells and 11.9 % of the surveyed; Parthenocissus vitacea - in 50 cells, which is 12.8 % of the total number of cells and 31.2 % of the number surveyed. Invasive status of Parthenocissus vitacea and Vinca minor is Category 3: Adventive species whose invasions into natural and semi-natural habitats in the region are currently isolated and, as a rule, confined to the outskirts of populated areas, abandoned parks, old plantings. The indicator of successful invasion in forest communities is the formation of syntaxonomically valid variants of the communities of Corylo avellanae-Pinetum sylvestris Bulokhov et Solomeshch 2003 with impoverished cenoflora. Invasive species change the phytosphere, reliably decrease the indices of б and в diversity, structural indicators of the communities. The invasion of Parthenocissus vitacea and Vinca minor is successful due to active vegetative reproduction, allelopathic effects on native species, and decrease of the illumination of the ground cover. The introduction of invasive species into complex pine forests blocks demutational changes of endogenous succession in the restoration of broad-leaved forests: they simplify the structure of serial communities, extend the period of vectorized changes, and reduce the intensity of the mosaic. Parthenocissus vitacea and Vinca minor can exhibit signs of an edificator, a community builder, a violent and a transformer-type. The radical transformation of the natural community is a unique single case registered on the territory of the nature monument “Lubin Khutor” (Novozybkovsky district, Bryansk region).

The diversity of life forms, the structure of individuals and ontomorphogenesis of T. extremus , T. indigirkensis , T. breviрetiolatus and T. pavlovii under the conditions of Yakutia have been studied. It has been established that the formation of two life forms and three types of biomorphs is characteristic of the species: a monocentric vegetatively-immobile dwarf subshrub ( T. extremus ), an implicitly polycentric vegetatively-semimobile dwarf subshrub and dwarf shrub ( T. indigirkensis and T. breviрetiolatus, respectively), obviously polycentric vegetatively-mobile dwarf subshrub ( T. pavlovii ). The basis of the adult bush is a monopodially-sympodially growing compound skeletal axis which differs in thyme specimens by the method of growth and position in space. An analysis of the development of species in Yakutia made it possible to identify common and specific features. Common features for species are the predominance of the dwarf subshrub living form and its morphological plasticity, a small diversity and shortening of the morphogenesis phases, a shallow rejuvenation of the ramet, a prolonged monopodial growth of shoots (up to 10 years), and the predominance of rosette shoots in the structure of the individual. Differences are revealed depending on the conditions of specific habitats of species. When T. extremus grows on a flat surface and high sludge, a dense primary shrub is formed. In the free areas of the substrate with stepwise depressions of the microrelief - the primary shrub of T. extremus is loose. In T. breviрetiolatus , which grows in the steppe on the hillside, the structure of the individual is formed only by rosette shoots, their prolonged monopodial growth is maintained due to the preservation (for 1-2 years) of dry leaves. For T. pavlovii , growing on a mossy substrate, it is characteristic lodging of shoots, their intensive rooting and strengthening of vegetative mobility, reduction of the duration of ontogenesis of individuals due to rapid decay of maternal structures. The revealed features of thyme development are the mechanisms of morphological adaptation which provide species survival in different environmental conditions of Yakutia.

The results of bird counts carried out over the period 1996-2017 in Inner-mountain Province of Daghestan were analyzed. The bird species composition, average population abundance and ecological pattern of avifauna in one of difficult-to-reach mountain areas of the republic are described for the first time. Cluster analysis showed that population patterns of the most sampling areas were not only similar but also unique because of high heterogeneity of habitats and, consequently, faunal differences, emerging in mountains under a lack of humidification. It was suggested that a specific pattern of the avifauna of Inner-mountain Daghestan is provided not only by resident communities of typical mountain birds but also by nesting in mountains adapted populations composed of migratory birds of valleys.

On the base of observational data of 2009-2015 the spatial, seasonal and interannual variability of sedimentary pigment content and biomass of macrozoobenthos in the Rybinsk Reservoir (Russia) are analyzed. The peculiarities of the macrozoobenthos distribution in dependence of characteristics of biotopes, including the content of sedimentary pigments, water depth, water content in bottom sediments and their air-dry volumetric mass are revealed. Using correlations and the principal component analysis, the statistically significant positive relationship between the biomass of macrozoobenthos and the content of the sum of sedimentary chlorophyll a with pheopigments is established.

The European mink ( Mustela lutreola ) is one of the most endangered mammals in Europe and has the status CR (Critically Endangered). In Russia the European mink disappeared from most of its former range too and its population numbers are extremely small. In the near future its reintroduction into former habitats using captive-raised animals will be needed. The exploratory behavior of captive-raised European minks was studied. Research was conducted in the nursery of the European mink in the Ilmen Nature Reserve. Thirty captive-raised European minks of different ages from 4.5 months up to 7 years (17 females and 13 males) participated in the experiments. It is shown that among the European minks which during several generations lived in cages or enclosures a well expressed dispersion on exploratory behavior has remained. Minks have kept ability to a fast exploration of the unfamiliar area and search of shelters. There were no differences between males and females in the value of the covered distance in the test. Age did not affect the activity of mink in their exploration of the territory and finding shelters. Differences in activity and division into groups according to the number of crossed squares within the sexes were due to personality of the minks. Individual features of behavior prevailed over group characteristics (sex, age). Despite continuous contacts with the staff, the majority of minks had no adaptation to people.