The specific use of nesting territory by the lesser sandhill crane in Yakutia

The left Indigirka riverside in Yakutia is the western periphery of the habitat of the lesser sandhill crane. The size of its population, time budget, and use of territory during the nesting season were studied in the period from 1998 to 2007. The density of population of this species is much lower here than in the northwest of Chukotka and in Alaska, which is reflected in the specific behavior of broods. For a decade, the size of its population increased more than 20 times.     

Radioecological situation at the villages of the Techa river

The Techa river was contaminated in 1949-1956 from the nuclear enterprise "Mayak". The investigations were carried out in flood plain of the Techa river in 1992-2001. 90Sr and 137Cs stores were calculated in the soil-vegetation cover. There is uneven character of the spatial radionuclides contamination of the investigated area. The store with 90Sr changes from 25 to 930 kBq/m2 (0.7-25.0 Ci/km2) and that with 137Cs--from 30 to 1700 kBq/m2 (0.8-46.0 Ci/km2). In the preriver-bed soils the ratio 90Sr/137Cs increases with further from discharge point. Individual effective dose was calculated for the Brodocalmak population. 90Sr was revealed in the flood plain soils of the Iset river. The contribution of the contaminated Techa river and its flood plains soils accounted for as by incorporated radionuclides as background gamma-radiation does not exceed 0.13-0.17 mSv/yr if the contaminated Techa river utilization is limited. In other case the contribution of the contaminated Techa river increases to 1.6-3.0 mSv/yr. These values exceed international safety norms.     

Radioecological problems of aquatic ecosystems of the chernobyl exclusion zone

The dynamics of the main contaminating radionuclides in the components of aquatic ecosystems within the Chernobyl APP exclusion zone is considered. The possible causes are analyzed for the marked increase in the specific activity of ⁹⁰Sr in water and hydrobionts of the lakes at the dammed left bank of river Pripyat. Notable is the elevated frequency of chromosomal aberrations in the root meristems of aquatic higher plants (up to 17%) and in the embryonal tissues of gastropod mollusks (up to 27%), alterations in the hematological indices for gastropods, and high infestation of aquatic higher plants by parasitic fungi and gall arthropods in the most radiocontaminated reservoirs.     

Male Seychelles warblers use territory budding to maximize lifetime fitness in a saturated environment

In cooperatively breeding species, helping at the nest and buddingoff part of the natal territory have been advanced as strategiesto increase fitness in an environment that is saturated withterritories. The importance of helping or territory buddingas a determinant of lifetime reproductive success (LRS) hasbeen debated because the potential benefits of both strategiescould not be separated. Here we test the causes and the immediateand future fitness consequences of single dispersal decisionstaken by male Seychelles warblers (Acrocephalus sechellensis).Males breeding in high-quality territories (high food abundance)have significantly higher LRS than similar-aged males buddingoff part of the parental territory. Initially, budders havea low reproductive success (because of limited food resourcesor absence of a breeding partner). However, they have a longlife span and inherit high-quality territories through sitedominance, by which they gain higher LRS than breeders on low-qualityterritories, helpers, or floaters. Experimental creation ofmale breeding territory vacancies showed that most young malesbecame budders because of intense competition for high-qualityterritories. The translocation of warblers to the previouslyunoccupied Aride Island shows that males behave according tothe expected fitness benefits of each dispersal strategy. Inthe absence of competition for territories on Aride, all youngmales bred in high-quality territories. However, after saturationof high-quality habitat with territories, most males becamebudders rather than breeders on low-quality habitat, helpers,or floaters.     

Cold adaptation in insects of Central Yakutia

The mode of cold hardening was for the first time assessed for 20 insect species living in the extremely cold climate of Yakutia. All insects tested were found to adapt through freeze tolerance, producing ice-nucleating agents that cause the hemolymph to freeze at high subzero temperatures. For the first time ice-nucleating agents were demonstrated in Lepidoptera. Pieris rapae exemplified the possibility of switchover in the survival strategy depending on the climatic conditions.     

Radioecological condition of cleansing structures on the territory contaminated with radionuclides as a result of the accident on the Chernobyl Nuclear Power Station and the problems handing with the forming precipitates of sewage in republic Belarus

This article deals with the problems, connected with the formation of radioactive deposits in sewage (D.S.). It's shown that the main places of the accumulation of D.S. are the fields of filtration, silty sites and biological pools. In order to reduce the extent of the risk of the secondary contamination of environment we could offer the modernization of the elements of the cleansing structures, the development of refining technologies and reduction of mobility of radiocaesium.     

Segetal vegetation of Central Yakutia

Seven associations of segetal vegetation are distinguished for the vast arable lands of Central Yakutia. Low species richness and the prevalence of annual weeds are the main features of these communities. Only two dominant speciesSphallerocarpus gracilis andSaussurea amara represent Asian types of areals. Other dominantsFallopia convolvulus, Elytrigia repens, Chenopodium album, Brassica campestris, Lappula squarrosa, Scutellaria galericulata, Thlaspi arvense, Avena fatua andCrepis tectorum are typically cosmopolitan. The phytosociological system of the segetal communities is described.     

杭州湾六市土地生态环境的数量评价及其在国土规划上的意义

在系统调查分析和特尔斐测定的基础上,选取人口密度、耕地人口负荷量、土地工业经济密度、居民点、厂矿用地、>25°土地面积、单位森林蓄积占用土地、耕地非旱涝保收面积7项指标,应用分值权重累加、系统聚类分析和模糊综合评价3种方法对杭州湾6市土地生态环境作综合分析评价,结果可应用于国土规划实践,对探讨土地生态环境评价的理论与方法有参考价值。     

Classification of ultracontinental boreal forests in central Yakutia

Using the Braun-Blanquet approach, five associations of boreal forests were distinguished in central Yakutia, the most continental part of eastern Siberia. Ecological features of the syntaxa were explained with the use of the DCA ordination of 50 relevés. All available data from eastern Siberia were involved in the study for syntaxonomic analysis. Central Yakutian boreal forests were classified into two classes:Rhytidio-Laricetea sibiricae Korotkov etErmakov 1999 — ultracontinental light coniferous hemiboreal forests, andVaccinio-Piceetea Br.-Bl. inBr.-Bl. et al. 1939 — typical coniferous taiga forests of northern Eurasia. A new concept of higher syntaxonomic units of the classVaccinio-Piceetea in eastern Siberia has been developed. Three orders represent the diversity of taiga forests: (1)Cladonio-Vaccinietalia Kielland-Lund 1967 (with alliancesHieracio umbellati-Pinion sylvestris Anenkhonov etChytry 1998 andSaxifrago bronchialis-Pinion sylvestris all. nov.) — light coniferous boreal forests occurring in dry and moderately dry oligotrophic sites in various climatic sectors of Northern Eurasia; (2)Lathyro humilis-Laricetalia cajanderi ord. nov. (with alliancesAulacomnio acuminati-Laricion cajanderi all. nov. andRhododendro daurici-Laricion gmelinii all. nov.) — zonal boreal forests with xeric elements, which are typical of regions of northern Asia with cold, dry ultracontinental climate; (3)Ledo-Laricetalia cajanderi ord. prov. (with allianceLedo-Laricion cajanderi prov.) — North Eurasian boreal forests occurring in cold sites with excessive soil moisture, sometimes water-logged. Phytogeography and ecology of these orders are discussed in comparison with other regions of northern Asia.     

Migration of Cs-137 in frozen soils of Yakutia

The present-day levels of 137Cs global fallout in frozen soils of the tundra and taiga zones of Yakutia are analyzed in the paper. Patterns of radionuclide migration in different types of zonal soils have been considered. Influence of the frozen forms of micro- and mesorelief over redistribution of 137Cs in soils is investigated. Mean velocities of vertical 137Cs migration in the main types of the frozen soils have been determined. We have found that mean velocity of 137Cs vertical migration in soil profiles depends on water condition and texture of soils.     

Anastomoses in the territory of the posterior cerebral arteries

Anastomoses in the region of the posterior cerebral arteries were found in all of 40 brains examined. Anastomoses were channel-like, plexiform or combined. The former measured from 0.07 mm to 1.1 mm in diameter. They were most often found among the interpeduncular perforating vessels (71.2%), and between the branches of the posterior and anterior cerebral arteries (75.7%). The functional significance of the anastomoses is discussed.     

Chondrichthyans from the Lower Carboniferous of Yakutia,Russia

Paleontological Journal - Teeth of Cladodoides cf. wildungensis (Jaekel), fin spines of Ctenacanthus cf. angulatus Newberry et Worthen and Ctenacanthus sp. occur in the Lower Carboniferous Emyaksin...     

Woody plants of Yakutia and low-temperature stress

Physiological and biochemical features of woody plants (Pinus sylvestris L. and Betula platyphylla Sukacz.) during transition from vegetative to frost-resistant state under conditions of extremely severe climate of Yakutia were studied. In P. sylvestris such transition was accompanied by a decrease in the content of chlorophylls long before first frosts and by an increase in the proportion of Xanth and simultaneous decrease in the content of β-carotene in needles during the first and second phases of hardening. In the period of preparation to dormancy, overwintering organs of both P. sylvestris (needles) and B. platyphylla (buds) accumulated the two groups of major dehydrins, with low mol wts of 15–21 kD and middle mol wts of 66–141 kD. Simultaneously, low temperature led to a great increase in the content of polyunsaturated fatty acids (FAs) in lipids of P. sylvestris needles and B. platyphylla buds, primarily linoleic acid and also eicosenoic FAs differing in the extent of desaturation. Observed qualitative and quantitative changes in pigments, total proteins, dehydrins, and FAs during autumn hardening of P. sylvestris and B. platyphylla plants presume their important role in the development of resistance of these tree species to low-temperature stress (down to −60°C) in the cryolithic zone of Yakutia.     

Cold adaptation strategy in insects inhabiting central Yakutia

Cold hardiness in 20 insect species living in extremely cold climate of Yakutia has been investigated for the first time. It was shown that the Yakutian insects prefer to use the strategy of freeze tolerance according to which they produce special substances initiating the freezing of hemolymph at high subzero temperatures. The presence of ice-nucleating agents in the haemolymph of insects belonging to the phylogenetic group of Lepidopteran was shown. We postulate that Pieris rapae may shift between the different cold hardiness strategies when they move from moderately cold regions to a more severe environment.     

On the fauna of Scathophagidae (Diptera) of Yakutia

The fauna of the family Scathophagidae of Yakutia, including 44 species of 15 genera, was studied. 23 species are recorded from the territory for the first time. The Arctic and subarctic zones of Yakutia have been still poorly studied, and additional species are found there. The scathophagid fauna of Yakutia was compared with the faunas of the neighboring regions using the dendrogram similarity method based on calculation of the Czekanowski–Sørensen coefficient.     

Avian flu in Altay territory

The avian flu epizootia among wild waterfowl and poultry in personal farmsteads is described. In 38.9% of tests from a sectioning material from bird's mass destruction the genetic materials of a influenza virus type A (H5N1), and in 24% of tests of serum antibodies to a influenza virus type A (H5N1) in diagnostic titers are revealed. It is carried out serological monitoring among workers of integrated poultry farms and the population. Activation of epizootic process in second half of summer and is predicted by Autumn, 2006. For the prevention of distribution of disease among birds and infection of the person carrying out of a complex of the actions directed on creation of quarantine for a wild waterfowl and restriction of contacts to a poultry, and on vaccine prevention from annual 100% immunization of workers of integrated poultry farms is necessary.     

Cost of territory establishment in hummingbirds

Summary Time spent in territorial defense was measured during territory establishment for non-breeding Black-chinned (Archilochus alexandri) and Anna's (Calypte anna) hummingbirds. Newly established territory holders spent more time chasing intruders than neighboring established owners, which served as controls. This higher investment in defense by the new owners was due to 1) a longer time spent per each chase and 2) in some cases, a higher frequency of chases at the onset of territory ownership.