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Thereuonema tuberculata (Wood, 1862), a centipede, is distributed mainly in Asia. In Japan, T. tuberculata is found throughout Honshu Island and southwards, although less commonly to the north on Hokkaido. Our survey additionally showed that this species occurs commonly at altitudes of 0-540 m on Hokkaido. The northern limit of this species in Japan seems to be Nakagawa Town, Hokkaido. Thereuonema tuberculata was also collected on isolated islands off southwestern Hokkaido. Although previous studies have suggested distribution of T. tuberculata in Hokkaido is anthropogenic, it may be natural. [ABSTRACT FROM AUTHOR]

After a long break since 1994, the dynamics of the structure and abundance of phytoplankton was studied again at different depths in the White Sea in March–November 2017. The microalgae abundance varied from 3.8 × 106 to 3519 × 106 cells/m3. Phytoplankton biomass ranged from 0.2 to 90 mg C/m3; it was the highest in the surface layer of the water column (0–5 m) with some exceptions. The algal abundance and biomass, integrated throughout the water column, varied from 0.2 × 109 to 68.5 × 109 cells/m2 and 0.01 to 1.38 g C/m2, respectively. Two peaks of phytoplankton biomass were identified, in early May after the ice melting and in early September. The summer peak of phytoplankton biomass, reported by previous studies in July in the surface layers, was not observed in 2017. This was caused by the dominance of smaller groups of nanoplanktonic prasinophytes, cryptophytes, and dinoflagellates. The change of dominant species may be related to the general tendency of decreasing the contribution of large species and increasing the share of heterotrophic taxa in the phytoplankton community due to more pronounced stratification of the water column caused by the climate warming. [ABSTRACT FROM AUTHOR]

The relevance of the research is related to the need for environmental monitoring of subarctic zone soils change in the Tyumen region at the stage of developing hydrocarbon deposits in modern conditions of transformation of the region into strategic base of Russia. The aim of the research is to evaluate the transformation of physical state and chemical composition of soils in subarctic zone of the Tyumen region under the influence of natural conditions and technogenic stress. Methods: landscape-geochemical and statistical, soil-geochemical studies, methods for determining chemical composition of organic and inorganic pollutants of soils, decoding of space images. Results. It is shown, that under the influence of anthropogenic load, which began in 1972, synlitogenic soils of floodplain are the most resistant to physical transformation and post-lithogenic soils – podzols – are the least resistant. The structure of soils, determined by the features of their formation and transformation should be considered the indicator of physical stability of soils. Podzols are the most susceptible to chemical transformations (on heavy metals), and floodplain soils and organogenic soils are the least susceptible; on organic matter – the soils of floodplains and organogenic soils, respectively. The indicator of chemical stability of soils is their ability to accumulate, move, release and transform inorganic and organic contamination. The area of physically transformed soils of this site at the stage of industrial development of the territory since 1972 has increased from 10,734 km2 (2008) to 11,705 km2 (2012).

Based on the NOAA climate datasets, trends, regional features, and possible causal relationships of interannual variations in water temperature on the surface (SST) and in the upper 750-meter layer of the subarctic Pacific with variations in the fields of air temperature, air pressure, wind, and climate indices over the past four decades are identified. The results revealed a degree of heterogeneity of the study region response to the ongoing global climate change, identified isolated areas, and quantified the warming rate in these areas. It is shown that in the west of the region, the SST trends are much higher than in the east, and in the warm season, they are about twice higher than in the cold season. Changes in water temperature and heat content anomalies in the water column of different regions are extremely uneven. The phases of alternating warm and cold periods are consistent with trends in the characteristics of the atmospheric centers of action, climate indices, and different climatic parameters. [ABSTRACT FROM AUTHOR]

Changes of soil properties along elevational gradients were studied in a less accessible and explored forest-tundra ecotone in the NW part of Central Siberia. Data on soil physical and chemical properties were collected along three horizontal transects at an elevation of 100–420 m a.s.l., at two localities differing in the slope angle. At each transect, five soil pits were excavated to a depth of 0.3–0.4 m. Soil samples were taken from the depths of 0–0.1 m, 0.1–0.2 m, and 0.2–0.3 m. The results showed a pronounced effect of slope angle on the pattern of soil properties along the elevational gradient. At the locality with a gentle slope, soils exhibited 2.5 times larger thickness of the surface organic layer (SOL), higher pH, and Na+ content, and lower C, N, Ald, and Fed concentration indicating slower pedogenic processes on this site. On the other hand, at the locality with a steeper slope, soil properties were better differentiated between transects situated along elevational gradient especially at the depths of 0.1–0.2 and 0.2–0.3 m. However, a clear positive or negative trend with the altitude was observed only for some soil characteristics, e.g., SOL, C, N, or Ald concentrations on the Lama location.

(1) Background: Boreal forests influence global carbon balance and fulfil multiple ecosystem services. Their vegetation growth and biomass are significantly affected by environmental conditions. In the present study we focused on one of the least accessible and least studied parts of the boreal region situated in the western part of Putorana plateau, Central Siberia (Lama and Keta lakes, Krasnoyarsk region), northern Russia. (2) Methods: We derived local height-diameter and crown radius-height models for six tree species. We used univariate correlation and multiple regression analyses to examine the relationships between tree biomass and environmental conditions. (3) Results: Total tree biomass stock (aboveground tree biomass + aboveground and buried deadwood) varied between 6.47 t/ha and 149 t/ha, while total deadwood biomass fluctuated from 0.06 to 21.45 t/ha. At Lama, biomass production decreased with elevation. At Keta, the relationship of biomass to elevation followed a U shape. Stand biomass changed with micro-terrain morphology and soil nutrient content, while the patterns were location-specific. (4) Conclusions: The majority of the derived models were significant and explained most of the variability in the relationships between tree diameter or crown radius and tree height. Micro-site environmental conditions had a substantial effect on tree biomass in the studied locations.

The characteristics of the annual cycles and the ecology of thrush birds in the Lower Priobye and the Yamal Penisula have been compared. The factors limiting the species migration northward and the perspectives on the range expansion in the subarctic region under the effects of the climate-related warming trend are analyzed. Annual cycles in thrush birds are rather common, despite their wintering in the different parts of Eurasia. The variations in the pattern of the annual cycle generally occur in the postnesting period. These variations concern the age at the onset of the postjuvenile molt, the type of molt control (photoperiodic or endogenous), the degree of overlap of postbreeding molting and nesting, and the degree of the molt-migration overlap. [ABSTRACT FROM AUTHOR]

The increase in tick-borne encephalitis (TBE) incidence is observed in recent decades in a number of subarctic countries. The reasons of it are widely discussed in scientific publications. The objective of this study was to understand if the climate change in Arkhangelsk Oblast (AO) situated in the north of European subarctic zone of Russia has real impact on the northward expansion of Ixodid ticks and stipulates the increase in TBE incidence. This study analyzes: TBE incidence in AO and throughout Russia, the results of Ixodid ticks collecting in a number of sites in AO, and TBE virus prevalence in those ticks, the data on tick bite incidence in AO, and meteorological data on AO mean annual air temperatures and precipitations.It is established that in recent years TBE incidence in AO tended to increase contrary to its apparent decrease nationwide. In last 10 years, there was nearly 50-fold rise in TBE incidence in AO when compared with 1980–1989. Probably, the increase both in mean annual air temperatures and temperatures during tick active season resulted in the northward expansion of Ixodes Persulcatus, main TBE virus vector. The Ixodid ticks expansion is confirmed both by the results of ticks flagging from the surface vegetation and by the tick bite incidence in the population of AO locations earlier free from ticks. Our mathematical (correlation and regression) analysis of available data revealed a distinct correlation between TBE incidence and the growth of mean annual air temperatures in AO in 1990–2009.Not ruling out other factors, we conclude that climate change contributed much to the TBE incidence increase in AO.

Background: The increase in tick-borne encephalitis (TBE) incidence is observed in recent decades in a number of subarctic countries. The reasons of it are widely discussed in scientific publications. The objective of this study was to understand if the climate change in Arkhangelsk Oblast (AO) situated in the north of European subarctic zone of Russia has real impact on the northward expansion of Ixodid ticks and stipulates the increase in TBE incidence. Methods: This study analyzes: TBE incidence in AO and throughout Russia, the results of Ixodid ticks collecting in a number of sites in AO, and TBE virus prevalence in those ticks, the data on tick bite incidence in AO, and meteorological data on AO mean annual air temperatures and precipitations. Results: It is established that in recent years TBE incidence in AO tended to increase contrary to its apparent decrease nationwide. In last 10 years, there was nearly 50-fold rise in TBE incidence in AO when compared with 1980--1989. Probably, the increase both in mean annual air temperatures and temperatures during tick active season resulted in the northward expansion of Ixodes Persulcatus, main TBE virus vector. The Ixodid ticks expansion is confirmed both by the results of ticks flagging from the surface vegetation and by the tick bite incidence in the population of AO locations earlier free from ticks. Our mathematical (correlation and regression) analysis of available data revealed a distinct correlation between TBE incidence and the growth of mean annual air temperatures in AO in 1990--2009. Conclusion: Not ruling out other factors, we conclude that climate change contributed much to the TBE incidence increase in AO. [ABSTRACT FROM AUTHOR]

The distribution and flux of planktonic foraminifera in the North Pacific Ocean were studied for a 1 year period beginning in July 1993 using time-series samples collected in three sediment traps deployed in a north–south transect along 175°E longitude. Sediment trap locations allowed monitoring of faunas within the Subarctic, Transition and Subtropical water masses in this region. Seasonally high foraminiferal flux rates were recorded at the Subarctic site during periods of intense stratification of surface water accompanied by high fluxes of organic matter and biogenic opal contents. Faunal composition dominated by sinistral forms of Neogloboquadrina pachyderma and Globigerina umbilicata at the latter site characterized the Subarctic water mass feature. Data collected at the Transitional and Subtropical sites illustrate differences in seasonal flux rates and in relation to those recorded at the Subarctic site. Faunal composition at the Transitional water mass site was dominated by dextral phenotypes of N. pachyderma, whereas this taxon was absent at the Subtropical site. Also, during the period of warmest surface temperature (October), Globigerinoides ruber became dominant at the Transitional water mass site in contrast to the Subtropical water mass site where Globigerinoides sacculifer became dominant while associated with common occurrences of Globigerinoides tenellus and Globorotalia tumida. Much lower fluxes of planktonic foraminifera, organic matter and biogenic opal also marked Subtropical water. The distinctive differences in faunal composition and flux rates at the Transitional and Subtropical sites suggest that little if any exchange of surface water occurred between these two sites and, in particular, in the area representing the distal Kuroshio Extension. [Copyright &y& Elsevier]

Changes of soil properties along elevational gradients were studied in a less accessible and explored forest-tundra ecotone in the NW part of Central Siberia. Data on soil physical and chemical properties were collected along three horizontal transects at an elevation of 100–420 m a.s.l., at two localities differing in the slope angle. At each transect, five soil pits were excavated to a depth of 0.3–0.4 m. Soil samples were taken from the depths of 0–0.1 m, 0.1–0.2 m, and 0.2–0.3 m. The results showed a pronounced effect of slope angle on the pattern of soil properties along the elevational gradient. At the locality with a gentle slope, soils exhibited 2.5 times larger thickness of the surface organic layer (SOL), higher pH, and Na+ content, and lower C, N, Ald, and Fed concentration indicating slower pedogenic processes on this site. On the other hand, at the locality with a steeper slope, soil properties were better differentiated between transects situated along elevational gradient especially at the depths of 0.1–0.2 and 0.2–0.3 m. However, a clear positive or negative trend with the altitude was observed only for some soil characteristics, e.g., SOL, C, N, or Ald concentrations on the Lama location. [ABSTRACT FROM AUTHOR]

(1) Background: Boreal forests influence global carbon balance and fulfil multiple ecosystem services. Their vegetation growth and biomass are significantly affected by environmental conditions. In the present study we focused on one of the least accessible and least studied parts of the boreal region situated in the western part of Putorana plateau, Central Siberia (Lama and Keta lakes, Krasnoyarsk region), northern Russia. (2) Methods: We derived local height-diameter and crown radius-height models for six tree species. We used univariate correlation and multiple regression analyses to examine the relationships between tree biomass and environmental conditions. (3) Results: Total tree biomass stock (aboveground tree biomass + aboveground and buried deadwood) varied between 6.47 t/ha and 149 t/ha, while total deadwood biomass fluctuated from 0.06 to 21.45 t/ha. At Lama, biomass production decreased with elevation. At Keta, the relationship of biomass to elevation followed a U shape. Stand biomass changed with micro-terrain morphology and soil nutrient content, while the patterns were location-specific. (4) Conclusions: The majority of the derived models were significant and explained most of the variability in the relationships between tree diameter or crown radius and tree height. Micro-site environmental conditions had a substantial effect on tree biomass in the studied locations. [ABSTRACT FROM AUTHOR]