Correlations between the contents of volatile compounds in needle samples from Scots pine populations of southern Siberia

Intrapopulation diversity and correlations of 30 volatile compounds in needles have been studied in Scots pine populations of southern Siberia. Significant differences between populations have been revealed in the correlation pattern of relative terpenoid contents in needle samples. Stable combinations of closely associated mono- and sesquiterpenes and specific features of the general pattern of correlations between relevant characters have been determined.     

Comparative analysis of small mammal communities in Chisinau and Yaroslavl, two European cities located in different biomes

Comparative analysis of the structure of small mammal communities has been performed in two European cities located in different biomes: Chisinau (2008?C2009) and Yaroslavl (1994?C2002). The parameters studied included abundance, species composition, similarity and difference of faunas, species diversity, and proportions of groups differing in predisposition to synanthropy. It has been found that the structure of small mammal communities in these cities depends on specific physiographic conditions of the surrounding areas and on the distinctive features of the cities themselves (their structure, age, etc.). The similarity between the faunas is accounted for by the common ecological patterns of fauna formation in the biota of urban cenoses.     

Intra- and Interpopulation Variation of Leaf Life Span in Rhododendronledebourii Pojark. and Rh. dauricum L. (Ericaceae Juss.) and Its Environmental Determination

Russian Journal of Ecology - Twenty cenopopulations of Rhododendron dauricum and Rh. ledebourii, two closely related and morphologically hardly distinguishable species, have been studied with...     

Impact of a small city on the structure of small mammal fauna in forests of the northeastern Moscow region

Forests in and around the reserve located near the city of Chernogolovka (50 km northeast of Moscow), forests adjoining the city, and urban forests were examined during the period from 1992 to 2004. Differences between forests of the reserve proved to be less significant than those resulting from the impact of urban factors. The influence of a small city was found to change the structure of communities of small mammals in surrounding forests by reducing their diversity and enhancing the dominance of ecologically restrained synanthropic species.     

Contributions of genotypic and meteorological factors to variation of annual tree increment in clonal scots pine plantations

Variation in radial increments of 28-year-old Pinus sylvestris L. clones in response to changes in weather conditions during the period between 1986 and 2007 has been studied in the Sredneobskii Bor pine forest. Significant genotypic differences in the adaptive reaction norm of the clones have been revealed. It has been shown that the contribution of genotypic differences to the total variance of test characters is usually significant and depends both on the conditions of growing season and on a given increment character.     

Sex Structure of Scotch Pine Populations in the Dry Steppe

it has been determined that the sex structure of the population is of great importance for pine adaptation to extreme environmental conditions. As environmental conditions deteriorate, differentiation of populations with respect to sex becomes more apparent, the proportion of trees of mixed type decreases, and the number of male trees increases. A tendency toward correlation between tree habitus, needle and shoot sizes, and the sex structure of population is noted. The prevalence of male trees in populations exposed to increasing stress reflects the rearrangement of such populations aimed at the more efficient use of natural resources.     

Genetic polymorphism of dwarf Scots pines in the south of Central Siberia

Polymorphism of 11 enzyme systems has been studied in dwarf Scots pine trees occurring on sand dunes and crags in two populations of southern Central Siberia. High genotypic variability of dwarfs and their similarity to normal trees in basic indices of genetic diversity have been revealed. Both populations, including normal and dwarf trees, are in the Hardy-Weinberg equilibrium. The sample of dwarf trees has proved to differ from the “norm” in showing an age-related trend toward decreased heterozygosity. The observed linkage disequilibrium at some pairs of loci can be explained by unequal contributions of trees to population reproduction or by a recent bottleneck event. The populations studied are similar to other Scots pine populations from the Asian part of the species range. Increased frequencies of some rare alleles in the populations from Tuva provide evidence for the probable presence of a glacial refugium for pine in this region.     

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.     

Structure of small mammal communities in Moscow parks and public gardens

Data collected between 1987 and 2002 have been used to analyze the structure of small mammal communities in parks and public gardens of the city of Moscow. With regard to several ecological parameters, four categories of parks markedly differing in biotopic conditions have been distinguished. The least stable zoocenoses are formed in deteriorating parks. More favorable ecological conditions exist in public gardens and regular parks, where not only synanthropic but also hemisynanthropic rodents can be found. The fauna of small mammals in landscape parks is similar to that in forest cenoses, but this fauna in park forests better complies with the concept of forest community.     

Changes in the sex structure of pine populations related to temperature anomalies

The results of ten-year observations on fluctuations in the sex of individual trees and the sex structure of tree stands in two insular pine forests in the south of Central Siberia are presented. It is noted that the ratio of sex types of pine trees has markedly changed since 1998–1999. Significant correlations between the sex structure of stands and anomalies of the annual average air temperature have been recorded since the early 1990s. The male generative sphere of pine has changed to the greatest extent. Periodicity and delay in the change of shoot sexualization in response to changes in temperature are discussed.