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1.
The linear increment of Sphagnum fuscum and S. magellanicum in ombrotrophic mires of Western Siberia has been measured during two years over a transect about 2500 km long extending from forest–steppe to forest–tundra. Along the latitudinal gradient, the increment of both species has proved to be correlated with annual average air temperature and, in S. magellanicum, also with annual precipitation. The determinants of their growth differ between the southern, central, and northern parts of the study region. At the regional level, the annual and summer precipitation plays a more important role than the average air temperature. The increment of S. fuscum in the southern part is positively correlated with the amount of precipitation and negatively correlated with summer temperature, whereas the situation in the central part is inverse. In S. magellanicum, the linear increment is directly dependent on the annual average temperature and annual and summer precipitation in the south and on the annual and summer precipitation in the north of Western Siberia. The dynamics of linear growth of both species in bog pine forests during the growing season are similar: its rate is the highest in June, when the linear increment of S. fuscum and S. magellanicum amounts to 60 and 85% of the annual total, respectively.  相似文献   

2.
The composition and contents of secondary metabolites in Flavocetraria lichens from Eastern Siberia were analyzed using herbarium specimens. Based on the composition of identified metabolites, three F. cucullata chemotypes and two F. nivalis chemotypes were distinguished. Distinct geographic differentiation between the F. cucullata chemotypes was revealed, probably reflecting their adaptation to environmental conditions. The content of usnic acid in F. cucullata thalli was found to correlate with the latitude of growing region. This may be regarded as evidence for a protective role of this metabolite in lichens growing at high latitudes and exposed to excess solar irradiation during the polar day.  相似文献   

3.
Experimental studies of interactions between two amphipod species (Gmelinoides fasciatus and Gammarus lacustris) showed that predation is the basic mechanism accounting for their mutual exclusion in nature. Mortality from predation among similar-sized specimens of both species at an equal abundance ratio was similar (24–25% in G. lacustris and 27–30% in G. fasciatus). The displacement of G. lacustris by G. fasciatus was observed when the latter was dominant. Adult G. fasciatus and G. lacustris successfully preyed on juveniles of their competitors and did not differ significantly in daily food consumption as a percentage of body weight: 6–24% at a fresh body weight of 18–24 mg in both species. The potential for rapid population growth under new conditions contributed to the success of the invasive Baikal species G. fasciatus in displacing G. lacustris from many water bodies of Russia.  相似文献   

4.
The accumulation of fluorine in the trunk wood and branches of Larix gmelinii growing on soils with a naturally increased fluoride content and of L. sibirica growing in a zone affected by atmospheric emissions from an aluminum plant has been studied. Based on results of in vivo and in vitro experiments, it is concluded that larch trees manifest individual differences in their response to fluorine.  相似文献   

5.
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.  相似文献   

6.
The effects of birch resistance induced by its artificial defoliation on the development of gypsy moth larvae and their sensitivity to viral infection and on the state of the antioxidant and detoxification systems of the insect midgut were studied. The dynamics of larval body weight; larval mortality and its etiology; glutathione-S-transferase (GT), nonspecific esterase (NE), and catalase (CAT) activities; and the ratio between the concentrations of oxidized and reduced thiol-containing compounds (RSSR/RSH) were estimated. In larvae feeding on the leaves of a previously defoliated plant, body weight was decreased, NE was inhibited, and the RSSR/RSH ratio was increased.  相似文献   

7.
The capacity of species for expansion and colonization of new habitats is a key condition for the maintenance of their populations. In this study, specific features of the reproductive potential have been analyzed in Lobaria pulmonaria populations growing under contrasting climatic conditions. Certain ecological determinants governing the development of this lichen species have been revealed.  相似文献   

8.
A comparative analysis of reproductive behavior has been performed in the steppe lemming (Lagurus lagurus) and narrow-skulled vole (Microtus gregalis). The results show that the species are similar in certain behavioral features indicative of the stability of mating pairs. However, in the narrow-skulled vole, unlike in the steppe lemming, mature males in olfactory tests show preference for receptive sibling females versus non-kin females. Probably, it is the absence of the incest taboo that allows the involvement of young of the year in reproduction within growing family groups and accounts for “coloniality” of the species.  相似文献   

9.
Life history traits of gypsy moth larvae markedly decrease under the effect of host plant insect resistance, but no significant changes occur in immunity parameters such as hemolymph phagocytic activity and lysozyme-like activity of hemolymph plasma and midgut tissue; moreover, alkaline protease activity in the midgut contents becomes higher. The actual sensitivity of the larvae to Bacillus thuringiensis remains unchanged.  相似文献   

10.
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.  相似文献   

11.
The contents of the digestive tract in sables (Martes zibellina L.) of known sex and age from the Middle Kolyma basin were examined to assess the winter diet in general and the frequencies of particular types of food in different sex and age groups of these animals. No statistically significant sex-related differences in the diet were revealed. This is probably explained by a considerable overlap of size and weight parameters between male and female Kolyma sables, due to which probable differences in their diets are leveled off.  相似文献   

12.
The allozyme analysis of six local populations of Pinus mugo Turra and six populations of P. sylvestris L. in the Ukrainian Carpathians, Swiss Alps, and Schwarzwald has shown a higher polymorphism and greater interpopulation differentiation of the Carpathian group of P. mugo populations compared to the Alpine group (Nei’s genetic distance DN 78 at the level of geographic population group is −0.023). A genetic differentiation of DN 78 = 0.049 between these populations, which are isolated by a distance of more than 1000 km, has been found. This confirms the existence of the subspecies P. mugo ssp. mugo and P. mugo ssp. uncinata in the Carpathians and Alps, respectively. The hypothesis is put forward that the former subspecies has been formed in the Balkans and the latter, in the Pyreneans. It has been demonstrated that regional populations and geographic groups of P. sylvestris are less differentiated than those of P. mugo.  相似文献   

13.
A discrete approach to the study of ontogeny has made it possible to reveal a high degree of age heterogeneity in P. bifurca cenopopulations. The basal ontogenetic spectrum of cenopopulations has been determined. The index of regeneration is higher in cenopopulations of the young type and decreases in cenopopulations of the old type, whereas the situation with the index of senescence is inverse. The density of cenopopulations depends mainly on parameters of the substrate (density, composition, and moisture), its slope, and the intensity of plant vegetative reproduction and spread.  相似文献   

14.
The contents of Al, Ti, Fe, Cr, Cu, Zn, As, Se, Cd, Pb, and rare earth elements (REEs) were determined in mosses (the hydrophyte Fontinalis antipyretica and the epiphyte Pylaisia polyantha) by the inductively coupled plasma-mass spectrometry (ICP-MS) method. These plants were used for estimating the spatial distribution of heavy metals (HMs) in the basins of small and medium rivers of Vologda and Kostroma oblasts (Russia). It was shown that water mosses are good indicators of REEs and epiphytic mosses, of the pollutant metals Cu, Zn, Se, and Pb. The epiphytic and hydrophytic mosses did not differ in the macroelement (Al, Ti, and Fe) content.  相似文献   

15.
The distribution of nine chloroplast DNA haplotypes in four insular North-Atlantic and four European coastal Atlantic populations of Calluna vulgaris in the glacial zone of the range has been analyzed in comparison with that in six marginal southern populations in the nonglacial zone of the Atlantic and Mediterranean regions. As a result, two hypothetical Pleistocene refugia (HPRs) for this C. vulgaris population group have been revealed, one in the Cévennes mountain range and the other in the Southern Alps (Trento). Judging from the 1–FST value, it has been found that the group of populations in the glacial Atlantic zone and adjacent European coastal Atlantic region is genetically similar to the HPR in the Cévennes at a highly significant level (p ≥ 0.999) and less similar to the HPR in Trento; however, it differs significantly from other Mediterranean and Atlantic populations. It has been concluded that the most probable hypothetical Pleistocene refugium for the recent C. vulgaris populations of the northeastern Atlantic and European coastal Atlantic regions was in the west of the Mediterranean, in the Cévennes, while the additional refugium was in the Southern Alps. Possible directions of the postglacial dispersal and recolonization of habitats by C. vulgaris populations from the western Mediterranean to the northeast of the Atlantic and to Scandinavia have been revealed.  相似文献   

16.
The return of willow ptarmigans to the sites in which they nested the previous year has been studied using color banding. No factors influencing the return index have been revealed, except for its dependence in males on the time when spring begins in a given year. In northernYamal, in contrast to the temperate zone, some surviving birds fail to return to their former nesting sites. Polymorphism of individuals with respect to territorial behavioral strategy is proposed for L. lagopus populations at the northern boundary of the species range.__________Translated from Ekologiya, No. 3, 2005, pp. 215–221.Original Russian Text Copyright © 2005 by Tarasov.  相似文献   

17.
The rates of lipid peroxidation (LPO) have been studied in Taraxacum officinale Wigg. (Asteraceae) and Vicia cracca L. (Fabaceae) from urban ecosystems with different levels of soil pollution with heavy metals (HMs), including Pb, Zn, Cu, and Cr. The former species responds to the increased HM contents by intensification of LPO processes, with their parameters correlating with the concentrations of Pb, Zn, and Cu in the soil. In the latter species from the same biotopes, conversely, LPO homeostasis remains actually undisturbed.  相似文献   

18.
19.
A study has been performed on the ecological, morphological, and genetic diversity of burbot (sample size n = 204 and n = 134, respectively) from eight localities of the Ob–Irtysh and Taz river basins, Western Siberia. Fish differentiation in body size and weight depending on the dominant type of migration behavior, foraging conditions, and physiographic features of habitats has been revealed. A high genetic diversity (854-bp mtDNA control region) and a low level of between-sample differentiation is evidence for high intergroup gene flow.  相似文献   

20.
The population of foxes in the central regions of Yakutia has grown by a factor of four to five during the period from 2000 to 2011–2012, following an increase in the abundance of voles from the genus Microtus. A total of 130 carcasses of foxes taken in 2007–2012 have been examined. Age- and sex-related variation in morphological features has been described. The demographic structure of the population has been studied by estimating animal age from annual layers in the recording structures. Changes in female fertility and involvement in reproduction depending on age and feeding conditions have been analyzed. Changes in the composition of fox diet caused by long-term population depression in the mountain hare and their effect on the dynamics of fox abundance have been revealed. Age- and sex-related characteristics of the condition factor in foxes and sex-related differences in their dietary preferences have been demonstrated.  相似文献   

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