Ecology of Nuclear Polyhedrosis Virus in Western Siberian Populations of the Gypsy Moth (<Emphasis Type="Italic">Lymantria dispar</Emphasis> L.)

The impact of the nuclear polyhedrosis virus on the population dynamics of the gypsy moth Lymantria dispar L. has been studied. The results have shown that polyhedrosis morbidity in the western Siberian population of the insect is relatively low, compared to that reported for North American and European populations. A possible cause of this situation is found in the high migration activity of moths in the Asian L. dispar populations, which allows the virus load on the biotope to remain relatively stable and insufficient for the initiation of mass viral diseases during population outbreaks.__________Translated from Ekologiya, No. 3, 2005, pp. 222–226.Original Russian Text Copyright © 2005 by Ilinykh.     

Estimation of the maximal population frequency of “alien” biotypes taking into account a priori data

A method is described for calculating the probability that the percentage of alien biotypes is higher than a specified threshold (e.g., 5%) in a population in which a certain number of alien biotypes has been found preliminarily. The method is based on the Bayesian approach; it assumes that the researcher has preliminary (a priori) information on the frequency of these biotypes. This a priori information makes it possible to estimate the aforementioned probability more accurately than is possible with the use of the standard binomial estimation. The method is illustrated by the results of the estimation of cultivar purity in batches of stock and foundation seeds of spring barley with the use of protein markers.Translated from Ekologiya, No. 2, 2005, pp. 106–109.Original Russian Text Copyright © 2005 by Zhivotovsky, Pomortsev, Lyalina, Kalabushkin, Pukhalskii.     

Gradient Genogeographic Analysis of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. Populations in Europe

Gradients of Nei's genetic distances between 15 samples of Pinus sylvestris L. trees were analyzed along three submeridional transects, from Scandinavia to the Mediterranean and Transcaucasia. As a result, distinct chorogenetic differentiation was revealed between the populations of this species growing in climatically specific regions of northern and southern Europe. Considerable Nei's distances (DN = 0.045–0.056) and their gradients, combined with differences in stable phenotypic characters (the composition of monoterpenes and morphological parameters of cones) determined at the Pyrenean and Caucasian mountain borders, suggest that the P. sylvestris species structure includes two South Eurasian subspecies, the Pyrenean P. sylvestris L., ssp. iberica Svoboda and the Transcaucasian P. sylvestris L., ssp. hamata (Stev.) Fomin.     

Acute and sublethal toxicity tests to monitor the impact of leachate on an aquatic environment

In this study, a specific landfill leachate (1200 mg l(-1) COD and 600 mg l(-1) BOD(5)) was used to develop a standardised short-term acute and longer-term sublethal ex-situ toxicity testing programme, in order to determine the potential ecological implications of leaching contaminants reaching the water table. Bioassays were undertaken with juvenile Gammarus pulex and Asellus aquaticus macro-invertebrates. Preliminary acute test variables included static and static renewed flow rates for 96-h, starved and fed specimens, and aerobic and oxygen depleting conditions. However, regardless of any test variable, the lethal concentration (LC(50)) for A. aquaticus remained at 12.3% v/v leachate in deionized water, whilst that for G. pulex was only 1%. Sublethal toxicity was judged on the basis of frequency of births and the growth rate of newly born individuals. Tests showed that even a dilution as high as 1:66- would influence the fecundity of a Gammarus population, whilst a dilution of 1:20 would affect the size of an Asellus breeding colony.     

Cladocerans under conditions of small river damming by man and beavers

In beaver ponds, the species diversity, abundance, biomass, and production of cladocerans and the amount of food consumed by them have increased and the composition of dominant species has changed as compared to those in the stretches of small rivers with running water or dammed by man. The stimulating effect of water from a beaver pond has been confirmed in laboratory experiments. The average number of juvenile Ceriodaphnia affinis produced by one female was considerably greater in this water than in the water from flowing and dammed (by man) river stretches.     

Soil organic carbon dynamics of croplands in European Russia: estimates from the “model of humus balance”

The Model of Humus Balance was used to estimate the influence of climate effects and changing agricultural practices on carbon (C) levels in soddy–podzolic soils in the Russian Federation for the years 2000–2050. The model was linked with a spatial database containing soil, climate and farming management layers for identification of spatial change of C sequestration potential. Analysis of relationships between C, soil texture and climate indicated that compared with a business-as-usual scenario, adaptation measures could increase the number of polygons storing soil organic carbon (SOC) by 2010–2020. The rate of possible C loss is sensitive to the different climate scenarios, with a maximum potential for SOC accumulation expected in 2030–2040, thereafter decreasing to 2050. The effect is most pronounced for the arid part of the study area under the emission scenario with the highest rate of increase in atmospheric CO₂ concentration, supporting findings from the dynamic SOC model, RothC. C sequestration during the study period was permanent for clay and clay loam soils with a C content of more than 2%, suggesting that C sequestration should be focused on highly fertile, fine-textured soils. We also show that spatial heterogeneity of soil texture can be a source of uncertainty for estimates of SOC dynamics at the regional scale. Figures in color are available at     

Specific features of the growth of Scots pine vegetative organs in the forest-steppe zone of Cisbaikalia

The dependence of the annual increment of vegetative organs on air temperature and humidity and the amount of precipitation per phenophase, as well as the period of their growth in Scots pine, were studied in the forest-steppe zone of Cisbaikalia. The multiple effect of variation in environmental conditions on the annual increment of organs increased when precipitation in September of the previous year was taken into account. These factors proved to have a stronger effect on variation in the annual increment of needles (R ² = 0.59, p = 0.00005) than that in the annual ring width (R ² = 0.38, p = 0.0002).     

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.