Changes in the species composition and abundance of young-of-the-year fishes in the upper Volga stretch of the Kuibyshev Reservoir during the period of 1991 to 2009

The species composition and abundance of young-of-the-year fishes have been analyzed in catches made in the upper Volga stretch of the Kuibyshev Reservoir between 1991 and 2009. It has been found that the juvenile abundance of roach and blue bream has decreased, while that of perch, silver bream, and spined loach has increased, with young-of-the-year juveniles of common rudd, tubenose goby, round goby, and black-striped pipefish appearing in catches. The results of the study show that, against the background of juvenile population decline in many spring-spawning fish species, the abundance and species diversity of young of the year in summer-spawning species has increased during the observation period.     

Changes in the ratio of plants with different mycorrhizal status in the course of pasture digression in the Southern Ural steppes

Trends in the proportions of plants differently interacting with mycorrhizal fungi in the course of pasture digression have been analyzed in the steppe zone of the Southern Urals. Estimates of species richness and abundance of plant groups with different mycorrhizal status have been obtained by comparing original data on the structure of phytocenoses with published data on the ability of plant species to form mycorrhizae. It has been shown that the proportions and abundance of obligate mycorrhizal species decrease significantly in the course of digression, with consequent increase in those of species less dependent on or independent of symbiosis with fungi, i.e., facultative mycorrhizal or obligate nonmycorrhizal plants.     

Changes in the structure of ichthyofauna in water bodies of Kaluga oblast over the past few decades

The structure of the ichthyofauna in water bodies of Kaluga oblast has undergone significant rearrangements over the past 20 years. The abundance of some species has increased, while that of other species has decreased; spontaneous dispersal of some fishes is underway. Synchronous fluctuations of fish abundance (“waves of life”) take place simultaneously in the Western Dvina, Dnieper, and Volga basins. These processes differ in intensity depending on fish species and are conditioned by a number of factors, including changes in hydrological regimes of rivers, improvement of the ecological state of small rivers, and increased poaching pressure. The results of monitoring the ichthyofauna fauna of small rivers are used as an example to trace the routes of fish dispersal and discuss changes in the composition of fish communities.     

Initial stages of recovery of epiphytic lichen communities after reduction of emissions from a copper smelter

Analysis has been made of changes in the species composition and abundance of epiphytic lichens on fir trees during the first decade after a sharp reduction of emissions from a large copper smelter in the Middle Urals. The results show that lichens have recolonized the area of the former lichen desert and that the abundance of lichen species in the impact and buffer zones has increased. However, a fairly long time is required before lichen communities in the vicinity of the smelter can recover to the background state, since species highly sensitive to pollution still occur only in the background area.     

Patterns of the formation of bird population in the lake-river system of the Asian Subarctic mountains based on the example of the Putorana Plateau

This paper analyzes the patterns of the formation of the aquatic and semiaquatic bird species population under the conditions of the altitudinal zonality of the Putorana Plateau. The population density and abundance of a number of background species was ascertained to decrease from the subalpine belt towards the forest and alpine belt. The bird population density in all the considered aquatic and semiaquatic habitats was revealed to change in a rather narrow range of values: the maximal population density indicator in aquatic and semiaquatic habitats is only 1.9 times higher than the minimal indicator. In the mountainous Subarctic region with a radial macrosymmetry, the spatial dynamics of abundance has a concentrically centrifugal nature in many aquatic and semiaquatic bird species.     

Prevalence and intensity of mycorrhiza formation in herbaceous plants with different types of ecological strategies in the Middle Urals

The prevalence of arbuscular mycorrhizas and abundance of mycorrhizal fungi in the roots of herbaceous plants with different types of Grime-Ramenskii’s ecological strategies (competitors, ruderals, and stress tolerators) have been studied in the Middle Urals. The closest association with arbuscular fungi has been observed in species with a competitive strategy. Compared to them, stress-tolerant species are characterized by lower abundance of mycorrhizal fungal hyphae in the root system, while ruderal plants include a relatively large proportion of nonmycotrophic species showing no interaction with arbuscular fungi.     

Structural-temporal organization of a rodent community in the Teletskaya Taiga,Altai Mountains

The structural-temporal organization of a murine rodent community in the taiga has been studied near Lake Teletskoe, Mountain Altai. The results show that the long-term dynamics of indices characterizing community diversity depend mainly on changes in the structure of dominance rather than on the population dynamics of species. The distribution of species in the factor space corresponds to their preference for certain biotopes, from dry to relatively moist. An analysis of relationships within the rodent community has revealed the synchronous dynamics of species abundance and antiphase pattern of changes in the structural indices of dominant species.     

Chernov’s compensation principle and the effect of rodent community completeness on the variability of bank vole (<Emphasis Type="Italic">Clethrionomys glareolus</Emphasis>) population in the Middle Urals

Using methods of geometric morphometrics, significant differences have been revealed in manifestations of variability and morphological disparity in allochronous samples from the population of model species, the bank vole (Clethrionomys glareolus Schreb. 1780), in the Middle Urals at different levels of rodent community (taxocene) completeness in different years. Two states of the taxocene—oligospecific (two species) and polyspecific (five species)—and the level of relative abundance of bank voles (high or low) have been taken into account. Comparative analysis of variation in the size and shape of the mandible in same-aged (late-summer) young of the year has shown that significant morphogenetic differences exist between the animals sampled from the rodent taxocene at its different states (oligospecific and polyspecific) and, to a lesser extent, at high and low levels of abundance. The level of variation and the parameter of intragroup morphological disparity (MNND) in the mandible shape reach a maximum when the community has a reduced composition and decrease to a minimum when its composition is complete (i.e., in the oligo- and polyspecific taxocene). A parallelism is observed in the manifestation of morphofunctional changes of the mandible in male and female voles under conditions when the taxocene has high abundance and oligospecific composition or low abundance but polyspecific composition. Different morphogenetic responses of the population to oligo- and polyspecific composition of the community are considered as a compensatory increase of morphological disparity in the dominant species (the bank vole) under conditions of incomplete composition of the taxocene and low population density, in accordance with Chernov’s ecological compensation principle.     

Assessment of the hunting of mammals using local ecological knowledge: an example from the Brazilian semiarid region

The hunting of wild animals remains a common activity in various parts of the world, especially in rural communities with poor socioeconomic conditions. To investigate patterns of mammal hunting, this study adopted a rural community located in semiarid Brazil as a model to test whether variables such as perceived abundance, activity period (day or night) and animal biomass could influence the consumption potential of mammal taxa. For this study, a checklist/interview technique using 32 photographs of mammals recorded in the region and two photographs of species that did not occur in the region, which acted as “control” species, was used, in addition to other visual stimuli and free lists. All species presented in the photographs, with the exception of the “control” species, were recognized as occurring in the region. Fourteen species were cited as being those most hunted locally. The species cited as most hunted had an average perceived abundance higher than the group of the least-hunted species. However, there was no significant relationship between hunting of a species and its locally perceived abundance. No significant difference in hunting pressure between diurnal and nocturnal species was found, nor was a relationship between animal biomass and hunting pressure observed. Our findings suggest that perceived abundance is an important factor for choosing a resource fauna, but other factors such as intended use, meat flavor and vulnerability to hunting, among others, may influence the potential use of a species.     

Changes in the dry tropical forests in Central India with human use

Understanding changes in forest composition and structure is important to help formulate effective policies that promote future ability of forests to provide local livelihood needs, habitat and ecosystem services. This is particularly important in dry tropical forests that are ecologically different from other forests and are heavily used by local, forest-dependent residents. In this study, we identify biophysical, demographic and use factors associated with differences in species diversity, vegetation structure (abundance at different size classes), biomass and relative abundance of species across the Kanha–Pench landscape in Central India. We sampled vegetation in twenty transects across different human and livestock population densities and frequencies of use. We found that biomass, species diversity and vegetation (abundance at different size classes) are negatively associated with increasing population density, and species composition at different size classes is significantly different at higher frequencies of use at low population densities. Lack of difference in species composition at high population densities may be due to colonization and growth of individuals at some of these sites due to creation of new ecological niches and gaps at high human use. Relative abundance of species at different size classes also varies with frequency of use and population density. Results suggest that human use is altering relative abundance of species, which may change long-term forest composition and thus alter biomass and vegetation structure of the forest. We conclude that human use is an agent in altering long-term composition that can alter availability of tree species for local use and other ecosystem services.     

The status of mammal populations in the middle Urals and factors determining their distribution and density

Changes in the distribution and abundance of some game mammals have been analyzed over the past 100–150 years. Correlations between changes in the population density of species in slightly and strongly transformed habitats have been revealed, which show that the influence of anthropogenic factors on the population density of species has a highly complex pattern. Transformation of habitats leads to disturbances in the species composition of communities, changes in the population density of species, and disruption of functional relationships between them.     

The role of floods in the Long-term dynamics of geobiont and chortobiont communities on islands of the Kuibyshev Reservoir

Interannual changes in geobiont and chortobiont abundance on the islands of Kuibyshev Reservoir are largely determined by flood conditions, because the seasonal average abundance of many taxa is negatively correlated to the water level in May and June. Floods influence the abundance of these animals both directly and indirectly, through biocenotic connections and some aspects of behavior. Long-term positive trends are observed in the abundance of many species. The hypothesis is proposed that this increase in the abundance of geobionts and chortobionts is a consequence of adaptation processes in these communities, which are stimulated by the flood regime of the reservoir.     

Specific features of the oribatid fauna in high-mountain pine forests of the Eastern Caucasus in relation to altitudinal zonality

The abundance, structure, and distribution of oribatid communities in high-mountain pine forest biotopes of the Eastern Caucasus are described in dependence on elevation above sea level. The oribatid fauna of high-mountain pine forests proved to be characterized by high abundance, an assortment of dominants, and species richness. It was shown that, as the elevation increases, specific dominants typical of particular altitudinal zones appear in communities, and changes in the mass species occur. These species are stable in terms of their long-term dynamics, and zonal groups (communities) demonstrate a high species diversity.     

Dynamics of the Mite Communities (Acari: Parasitiformes) in Nests of the Parus major

The dynamics of nest-dwelling mites from the nests of the great tit in the protected area of Kamchia Mountain in Northeastern Bulgaria was investigated. The mite fauna inhabiting the nests of great tit differs significantly in terms of the degree of infestation, species richness, abundance and structure of communities in study years. There are statistically significant differences in the specimens’ number between 2014 and the other years 2012, 2013 and 2015. The mite species such as Dermanyssus gallinae, Androlaelaps casalis and Ornithonyssus sylviarum demonstrated significant changes in the abundance over the study years. A relation between the abundance of a species and the species diversity in the nests was not registered. Comparison of the annual dynamics of mites in the nests of great tit and the nests of semi-collared flycatcher for the same period of time and for the same environment, showed similarities—a significant fluctuation in the abundance of mites over the years and differences—in the species richness. Regarding the structure of the communities, both similarities and differences were recorded.

     

Abundance of orchids on calcareous grasslands in relation to community species,environmental, and vegetational conditions

The abundance of Orchidaceae on three calcareous grasslands is studied in relation to floristic composition, environmental and vegetational factors and plant traits (ecological and life forms). The aims are: (i) to identify a group of species that is significantly correlated with the abundance of Orchidaceae or with individual species of orchids on calcareous grasslands; (ii) to study the relationship between traits associated with habitat specialisation, community life forms and the abundance of orchids; (iii) to identify the main environmental and vegetational predictors of the abundance of orchids. A shortlist of species is found to be significantly correlated with the abundance of total orchids, Orchis pauciflora and O. morio. The life forms of the community species do not show any correlation with the orchids, with the exception of Orchis pauciflora, which tends to increase in communities rich in hemicryptophytes and poor in annual species. Analyses of Orchis morio seem to suggest that it has a high level of ecological tolerance. The most important predictors of the abundance of orchids are the substrate reaction (basic) and arid grassland with low herbaceous vegetation cover (i.e. high soil reaction and luminosity values, positive correlation with the cover of lichens and rockiness, negative correlation with tree cover and herbaceous layer). The least favourable sites were the least basic and most superficial and arid sites.     

三峡水库春季浮游植物群落特征及影响因素

浮游植物群落特征是水域生态系统的一个基础信息,三峡水库作为长江经济带环境保护的重要区域,而关于三峡水库全水域浮游植物群落特征及其影响因素的研究报道仍不多见。为了解三峡水库浮游植物群落特征差异及影响因素等一系列基础信息,于2015年4月对三峡水库进行了大范围的调查,调查范围包括17个长江断面(共51个样点)及22条支流库湾(共122个样点)。结果显示:共采集到浮游植物7门39属61种,以绿藻门、硅藻门、甲藻门为主,其中绿藻门有26种,占据总种数的42.62%;硅藻门有16种,占据总种数的26.23%;甲藻门有7种,占据总种数的11.48%。丰度方面,硅藻门占绝对优势,比例为34.26%,其次是隐藻门(23.72%)、蓝藻门(20.96%)。生物量方面,则是甲藻门占绝对优势,其比例达到了44.18%,随后是隐藻门(29.92%)、硅藻门(14.32%)。丰度和生物量分别变化在2.22×10~4～5.12×10~(7 )cells/L和0.001 8～120.99 mg/L之间,且存在一致的趋势,从三峡大坝往长江上游,丰度值和生物量值逐渐增加。支流库湾浮游植物Shannon-Wiener多样性指数显著高于长江干流(Mann-Whitney U检验,P0.001)。冗余分析(Redundancy Analysis,RDA)表明,在长江干流中,水温(WT)、可溶性硅酸盐(DSi)是影响浮游植物群落结构的主要环境因子(P0.001);在支流库湾中,硝态氮(NO~-_3-N)、水温(WT)是影响浮游植物群落结构的主要环境因子(P=0.002)。该研究的成果有助于全面认识了解三峡水库长江干流和支流库湾春季浮游植物种类组成和影响因子,同时对三峡水库水资源管理和水生态保护具有一定参考价值。     

Saturation and invasion resistance of non-interactive plant communities

Open plant assemblages in shoals of western Caucasian rivers were used as examples to analyze the relationship between the species saturation and the number and total abundance of alien species in non-interactive communities. Invasion of exotic species into highly saturated communities has been demonstrated to be, on average, less probable than their invasion into unsaturated communities. A hypothesis explaining the relationship between these parameters has been put forward. According to the hypothesis, the number of alien species in a specific locality in a community is determined by their ratio to the number of native species in the species pools of these communities; and their mean abundance, by the ratio of the total number of species to the number of individuals in the localities. Both ratios are smaller in saturated biocenoses, which determines a relatively small admixture of alien species in them.     

Using the useful: characteristics of used palms in south-eastern Ecuador

Plant families differ greatly with regard to their usefulness to humans. Within families there are also large differences in the usefulness between species; some are used for many different purposes, while most are used for few or no purposes. Which ones and to what extent species are used often varies between areas and cultural groups. To better understand variation in speciesȁ9 usefulness we studied the use of different palm species (Arecaceae) among two socio-cultural groups (one indigenous and one colonist group of mixed ethnic descent) living in the same area. We used regression and correlation analyses to determine to what degree use is related to ecological and morphological characteristics, to geographical differences in abundance, and to peopleȁ9s perceptions of speciesȁ9 availability. We found that abundance and height were the most important characteristics related to use, possibly due to the effect of height and abundance on salience, search time, and (for height) suitability for different purposes. Abundance was most important for palm heart extraction, probably due to the opportunistic nature of this activity. There was no difference between socio-cultural groups with regard to the relationship between palm abundance and use, but abundance seemed to be more decisive for people who used moderate amounts of palms. Finally, it was seen that peopleȁ9s estimates of palm abundance were not related to our measurements of abundance, which may be due to use of different spatial scales in evaluating abundance and to the subjective nature of terms such as “rare” and “abundant”.     

Abundance and community structure of bats (Chiroptera: Vespertilionidae) hibernating in artificial caves of Samarskaya Luka

The structure of hibernating bat communities has been studied in eight artificial caves of Samarskaya Luka differing in size and layout. Three types of the relative abundance distribution (RAD) of species in these communities have been revealed. Conditions for hibernation are most favorable in large caves with a stable microclimate, where the abundance of bats is high, the Shannon index has the peak values, and variation in the index of species evenness is the lowest. In such caves, RAD fits the broken-stick and log-series models. Variation in diversity indices reaches the highest level in shallow adits with a changeable microclimate, where RAD fits the geometric series model. The abundance, diversity, and structure of communities depend mainly on cave size and the presence of absence of drafts and, to a lesser extent, on ambient temperature, availability of microshelters, and the type of landscape surrounding the cave. Anthropogenic factors have a weak effect only on the abundance of individual species (M. nattereri, M. daubentonii, M. dasycneme, and E. nilssonii) but not on the overall diversity of bat communities.     

Impact of fires on the fauna of terrestrial arthropods in protected steppe ecosystems

The abundance of terrestrial arthropods in the Orenburgskii Nature Reserve has decreased since its establishment in 1989. At present, this parameter fluctuates considerably, and the species composition of arthropods is changing in favor of xerobiontic and eurybiontic species. These changes result from the absence of grazing load as well as from periodic fires. Therefore, it is necessary to organize controlled livestock grazing and reliable fire protection in reserved areas.