Combined influence of food level and inoculation density on competition between <Emphasis Type="Italic">Anuraeopsis fissa</Emphasis> and <Emphasis Type="Italic">Brachionus patulus</Emphasis> or <Emphasis Type="Italic">Brachionus macracanthus</Emphasis> (Rotifera: Brachionidae)

We tested separately the effect of two taxonomically related rotifers (B. patulus and B. macracanthus) on the population dynamics of another species (A. fissa) at low (0.5 ×10 ⁶) and high food levels (1.5 × 10⁶ cells/ml of Chlorella vulgaris) using different inoculation densities (0–100%). We also quantified the impact of A. fissa on the two brachionid species. Regardless of the presence of the competing species, an increase in the availability of food led to increase in the abundances of the three rotifers. The population growth of B. patulus, B. macracanthus, or A. fissa was affected negatively when cultured together with another species. An increase in the initial density of any one of the competing species became advantageous to maintain a certain population size. At a low algal food level, B. patulus was able to suppress A. fissa more strongly than B. macracanthus. On the other hand, at a high food level, B. macracanthus suppressed the population of A. fissa more strongly than B. patulus. Peak population densities for A. fissa varied from about 150 to 1000 ind./ml, depending on food density and the presence of competitors. The rate of population increase (r) of A. fissa, B. patulus, and B. macracanthus increased with an increase in food availability but decreased with increasing initial density of the competitor. Both Brachionus spp. experienced negative growth rates in the presence of A. fissa, especially at a high initial density of the latter. Published in Russian in Ekologiya, 2007, Vol. 38, No. 5, pp. 381–390. The article was submitted by the authors in English.     

Changes of leaf morphology in <Emphasis Type="Italic">Betula pendula</Emphasis> roth and <Emphasis Type="Italic">B. pubescens</Emphasis> Ehrh. along a zonal-climatic transect in the Urals and Western Siberia

Leaf size, shape, and parameters of venation in Betula pendula and B. pubescens have been studied along a 1600-km latitudinal zonal transect in the Urals and Western Siberia. The results show that leaf size and venation density depend on the geographic location of population, with these parameters in the two species changing in opposite directions along the transect. In its northern part (forest tundra-southern taiga), B. pubescens shows a positive correlation of leaf area with long-term-average air temperature, while this correlation in B. pendula is negative. In the southern part, correlations of leaf size with long-term average precipitation in the two species are also opposite in sign. Parameters of leaf shape in both species depend mainly on weather conditions in the current year rather than on long-term average climatic parameters. The conclusion is drawn that B. pendula and B. pubescens have different mechanisms of structural adaptation of leaves to climate and weather conditions that are based on changes in leaf size and shape.     

Analysis of rodent populations in technogenically transformed areas (with reference to <Emphasis Type="Italic">Apodemus</Emphasis> (<Emphasis Type="Italic">S.</Emphasis>) <Emphasis Type="Italic">uralensis</Emphasis> from the EURT zone)

It is shown that the response of rodent populations to acute and chronic irradiation depends on its functional structure, i.e., on specific features of animals with two alternative types of ontogenetic development. Upon acute irradiation, sexually immature young of the year (animals with the second type of ontogeny) are most radioresistant. Exposure to chronic irradiation, as in the zone of the Eastern Ural Radioactive Trace (EURT), leads to an increase in the proportion of mature young of the year (animals with the first type of ontogeny), which are the most radiosensitive part of the population. The abundance and fecundity of mice in the impact zone are consistently higher than in the background zone, which improves the adaptive potential of the population. The role of species ecological specialization and configuration of the contaminated zone in the formation of migrant rodent population is emphasized. It is concluded that a high migration activity allows the pigmy wood mouse (a radiosensitive species) to avoid long-term radiation exposure.     

On the term <Emphasis Type="Italic">Station</Emphasis> used in Russian ecological and faunistic literature

The history of the term station (in Russian, statsiya) in the Russian ecological and faunistic literature, interpretation of its meaning by different authors, and relationships between the terms station, habitat, biotope, and ecological license are discussed. It is suggested that station should be interpreted as the entire set of all external conditions affecting a population, which is observable as a part of physical space possessing certain properties.     

Characteristics of Cajander Larch (<Emphasis Type="Italic">Larix cajanderi</Emphasis> Mayr) on Dredging Waste Dumps in the Amur Region

Former dredging sites were studied in the taiga zone of the Amur region (in Khabarovsk Krai). The involvement of Larix cajanderi in plant succession on dredging waste dumps was revealed. Some morphological-anatomical parameters of L. cajanderi needles were compared in trees growing on the dumps and in adjacent open larch stands on waterlogged peaty soils.__________Translated from Ekologiya, No. 4, 2005, pp. 259–263.Original Russian Text Copyright © 2005 by Osipov, Burundukova.     

Influence of intra- and interspecific competition on daily activity of common (<Emphasis Type="Italic">Microtus arvalis</Emphasis>) and East European (<Emphasis Type="Italic">Microtus rossiaemeridionalis</Emphasis>) voles in experiments

The influence of intra- and interspecific competition of common and East European voles on their daily activity was studied in 34-m² enclosures at the Chernogolovka Experimental Research Station (Moscow Region). Family groups of animals captured in the same biotopes were placed in enclosures and, 25 day later, their daily activity was observed. Thereafter, the animals were pooled and observations were repeated 25 days later. The experiment consisted of three stages. At the first stage, the daily activity, time budget, and social behavior of common voles were studied before and after pooling different family groups; at the second stage, the same was performed with East European voles; and at the third stage, with both species. The species proved to use different strategies for alleviating intraspecific competition: in common voles, this was segregation of ecological niches via desynchronization of daily activity; in East European voles, conversely, aggregation in groups and synchronization of activity. Under experimental cohabitation, the strategy of the common vole, a more aggressive species, was to force out the other species, ecologically similar but less competitive; the strategy of the East European vole was aimed at avoidance via segregation of ecological niches in time.     

Spatial distribution and mobility of butterflies in a population of the cranberry fritillary <Emphasis Type="Italic">Boloria aquilonaris</Emphasis> (Lepidoptera,Nymphalidae)

A population of the cranberry fritillary (Boloria aquilonaris) was studied in a forest bog in Southern Karelia. The butterflies in this habitat were distributed unevenly, forming large aggregations in the driest sites overgrown by Comarum palustre. All areas inhabited by the population were interconnected by fluxes of butterflies. The maximum recorded distance covered by a an individual was 1.5 km. The B. aquilonaris residence area was delimited on the basis of an exponential model. Specific features of the spatial organization of B. aquilonaris populations in spatially homogeneous and fragmented environments are discussed.     

Intrapopulation spatial segregation in bream (<Emphasis Type="Italic">Abramis brama</Emphasis>) and roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis>) in the Rybinsk Reservoir

In the course of studies on mass fish species (bream and roach) in water bodies of the Upper Volga basin, intraspecific groups of individuals have been distinguished. Conditions and possible mechanisms of spatial differentiation of these groups are considered. The intrapopulation divergence of individuals by some adaptive characters, primarily behavioral, enables them to utilize alternative resources, which provides for more efficient use of the environment by populations.     

Effects of the <Emphasis Type="Italic">Astacus astacus</Emphasis> L. Population on Biomass of Macrophytes in a Fresh Water Body

In experiments performed in aquariums, the daily consumption of Chara vulgaris alga by crayfish (Astacus astacus L.) has been determined. These quantitative data have been used to make a prognosis of the effect of the A. astacus population on the biomass of macrophytes in Lake Berezovo (Pskov oblast). The density of the crayfish population and the biomass of higher aquatic vegetation in the lake have been determined in field studies. Extrapolation of the results of laboratory experiments to a natural water body has shown that crayfish are capable of controlling no less than 40% of submersed macrophytes in the area used by their population.__________Translated from Ekologiya, No. 4, 2005, pp. 300–305.Original Russian Text Copyright © 2005 by Kholodkevich, Shumilova, Fedotov, Zhuravlev.     

Breeding habitat characteristics and nest survival of yellow-rumped flycatcher (<Emphasis Type="Italic">Ficedula zanthopygia</Emphasis>) in natural tree-cavities

Studies of nest-site selection and reproduction are essential for bird species assessment and conservation. We compared breeding habitats and random sites within a secondary cavity-nesting bird, Yellowrumped Flycatcher (Ficedula zanthopygia), in a 5-year studying period in northeast China. We also modeled the effects of factors on daily nest survival rates. The flycatcher nest cavities were mostly located in tree trunks, with only 15% found in limbs. They often located their nests in east and south direction (45°–180°) with dense canopy cover surrounding the nest trees. Yellow-rumped Flycatcher nest-site selection appears to be nonrandom, such that they select nest sites with higher tree density and higher canopy closure. Yellowrumped Flycatcher daily nest survival rate was 0.9731 ± 0.007. Daily nest survival increased with increasing percent cover of canopy closure and decreased with the distance closing to the edges. The causes for nest failure were mainly nest usurpation by other secondary cavity-nesters. Predation rate and the competition for cavities with other secondary cavity-nesters may constrain the ability of Yellow-rumped Flycatchers to optimize nest nest-site selection.     

Sixty years of habitat decline: impact of land-cover changes in northern Italy on the decreasing ortolan bunting <Emphasis Type="Italic">Emberiza hortulana</Emphasis>

Habitat loss and degradation are main global threats to biodiversity, and land-use changes in agriculture-dominated landscapes are crucial for an important portion of biodiversity, especially in Europe. We evaluated the effects of land-use changes (1954–2012) on a threatened species, the ortolan bunting, in an agricultural area crucial for its conservation in Italy. We built a distribution model for ortolan bunting in current landscapes and then re-projected it to past scenarios (1954 and 1999–2000). We evaluated the most important land-use changes occurred and estimated their effects on habitat suitability. Bunting occurrence was mostly affected by the extent of grassland (positively; used as foraging/breeding ground), shrubland (quadratic effect; perches/shelter), forest and urbanized land (negatively), and by solar radiation (positively) and slope (quadratic), consistent with other studies carried out especially in southern Europe. The potential distribution of the species was much larger in the past: the estimated decline in suitable habitat is 44–72 % (since 1999–2000/1954), coherent with historical data suggesting strong decline and contraction. Changes in suitability (1954–2012) were mostly associated with changes in the cover of forest, vineyards and abandoned areas (negatively), and shrubland (positively). Land-use/land-cover changes are the main drivers of species occurrence and of habitat decline. The heterogeneous landscape of hilly/low-mountain sites in this area, characterized by a mix of habitats offering complementary resources to ortolan buntings and other species of conservation concern, is currently threatened by abandonment and intensification, but its maintenance may be promoted by a correct definition of Rural Development Programme measures.     

Relationships between developmental instability in morphological characters and fitness of <Emphasis Type="Italic">Aphis fabae</Emphasis> population reared on two host plants

Fluctuating asymmetry (FA) and the coefficient of within-environment variation (CV _e) are often used as measures of developmental instability and indicators of developmental deviations. Aphis fabae genotypes generally manifest higher developmental instability on novel host plants, but there is genotypic variability in this respect. Some genotypes have manifested lower developmental instability on nasturtium, where their fitness is higher. At the population level, aphids reared on nasturtium have shown higher developmental instability and lower fitness. When large samples are analyzed and the nonsignificant pattern of correlations is taken into account, the results of the study do not support the hypothesis that developmental instability is always a reliable indicator of fitness. Published in Russian in Ekologiya, 2007, Vol. 38, No. 2, pp. 131–136. The text was submitted by the authors in English.     

Insularization and polymorphism in marginal island populations of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.

Comparative allozyme analysis of 26 marginal island populations of Pinus sylvestris L. and 20 populations from the center of the species range has confirmed, at the species level, the Wright-Dubinin “island model” of automatic genetic processes and Mayr’s hypothesis about homozygotization of small isolated populations at range boundaries. It has been shown that the polymorphism of isolated populations sharply decreases when their area is reduced below 15–20 km² and increases to the level observed in the center of the range when the population area exceeds 50–100 km². A chorogenetic classification of marginal P. sylvestris populations is proposed.     

MANAGING POLLUTION FROM SSI<Emphasis Type="SmallCaps">s</Emphasis> – DESIGNING FOR A SUSTAINABLE INSTITUTION

The common effluent treatment plants (CETPs) are being propagated as the policy response to circumvent the pollution problem from the small-scale industries (SSIs), which abound in developing countries. The formation of the CETPs has been hailed as a collective action or co-operative solution to a common problem involving all the agents responsible for pollution. This paper investigated the desired criteria for designing an institution aimed at solving a common resource problem and factors ensuring the smooth functioning or sustainability of the institution. The design criteria and factors are then tested on a CETP set up in the Indian state of Haryana. The CETP, which was commissioned in 1997 had to be converted to a sewage treatment plant (STP) as the collective arrangement collapsed. The criteria used in the present analysis are that of Ostrom’s [Governing the Commons. Cambridge, UK, Cambridge University Press, 1990] design principles, whereas the factors considered for sustainability are the one suggested by Rawls [A Theory of Justice. USA, Harvard University Press, 1971]. The analysis indicates that the Kundli CETP failed in both counts as neither all the design principles were met nor did the institution fulfil different sustainability criteria. The paper concludes with the lessons that can be learnt from Kundli’s failure. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

The narrow-skulled vole (<Emphasis Type="Italic">Microtus gregalis</Emphasis> Pall.) in the dynamics of zonal rodent communities of northern Eurasia

On the basis of abundant fossil and subfossil bone remains, the ecological and faunal role of the narrow-skulled vole in zonal rodent communities of northern Eurasia is analyzed over the period from the Late Pleistocene to the present time. Special attention is given to the correlated dynamics of relative abundance of Microtus gregalis and other rodent species in the course of transition from one zonal type to another and to specific features of this correlation in the southern, middle, and northern parts of the species range. It is shown that distinctive dimensional and morphotypic features of the two currently existing subspecies, Microtus gregalis major Ogn. and M. g. gregalis Pall., are the product of concordant development of the species and environmental conditions in the past 3000–4000 years (transition from the Holocene optimum to the present-day climate and state of the natural environment). Published in Russian in Ekologiya, 2007, Vol. 38, No. 2, pp. 117–123. The article was translated by the authors.     

Influence of silts on the growth,reproduction and chlorophyll fluorescence of <Emphasis Type="Italic">Potamogeton crispus</Emphasis> in turbid water

Turions of Potamogeton crispus were planted in several turbid waters. Some parameters of growth, reproduction and chlorophyll fluorescence were measured. The results were as follows: (1) Sprouting rates in all groups reached to 100.0% on the 17^th day. (2) The parameters of the growth (stem and leaf) and chlorophyll fluorescence (Φ_PSII, qP and qN) in 120 and 150NTU waters were inhibited heavily 60 days later, and their survival time was only 140 days. However, the plants in 30 to 90NTU waters could grow near water surface, their survival time was about 190 days. (3) After 150 days, the saturating irradiance intensity and rETR_max of the leaves in 30 to 90NTU waters markedly decreased with an increase in the amount of attached silts, and the number and fresh mass of turions (propagula) in 60 and 90NTU waters were significantly lower than the control. In summary, P. crispus in 0.7-metre-deep turbid water with suspended silts (not more than 90NTU) could sprout and grow normally, and produce the turions.     

Reproductive allocation patterns in different edaphic types populations of <Emphasis Type="Italic">Haloxylon ammodendron</Emphasis> in Gurbantünggüt desert

The reproductive allocation (RA) of Haloxylon ammodendron (C.A. Mey.) Bunge was studied in different edaphic types of the Gurbantünggüt desert. Results showed that the RA had significant hierarchical variation. Both RA and reproductive output (RO) were size-dependent, and relationships between above-ground total biomass and RA/RO were represented by linear or exponential equations. The RA in loam increased with aboveground total biomass increased. However, the RA showed a faint decrease in gravel soil and significant decrease in sandy soil with aboveground total biomass increased. Then, the stability of the population was analyzed in three edaphic types.     

The gyrfalcon, <Emphasis Type="Italic">Falco rusticolus</Emphasis>, in the Yamal Peninsula: Dynamics of brood size and nest size over the years 1973–2008

The gyrfalcon in the Yamal Peninsula nests mostly on trees. The average brood size in this species decreased from 3.1 nestlings per active nest (n = 28) between 1973 and 1989 to 2.2 (n = 22) between 1998 and 2008. This decrease is probably explained by switching to the habit of using mostly smaller nests (built by the rough-legged buzzard, raven, or hooded crow) instead of large nests built by the white-tailed eagle. The survival rate of gyrfalcon nestlings in smaller nests is considerably lower: the average brood size is only 1.6 (n = 12), compared to 2.5 (n = 20) in medium-sized and 3.0 (n = 34) in large nests. The possible role of increase in snow cover density caused by climate warming in making large nests less accessible to the gyrfalcon is discussed.