Eastern Siberian Research Articles

Total Ozone Mapping Spectrometer (TOMS) observations of increases in Asian aerosol in winter from 1979 to 2000

Emission inventories indicate that the largest increases in SO2 emissions have occurred in Asia during the last 20 years. By inference, the largest increases in aerosol, produced primarily by the conversion of SO2 to sulfate, should have occurred in Asia during the same time period. Decadal changes in regional aerosol optical depths are calculated by analyzing Total Ozone Mapping Spectrometer (TOMS) vertical aerosol optical depths (converted to 550 nm) from 1979 to 2000 on a 1° by 1° global grid. The anthropogenic component of the TOMS aerosol record is maximized by examining the seasonal cycles of desert dust and boreal fire smoke and identifying the months of the year for which the desert dust and boreal fire smoke are least conspicuous. Gobi and Taklimakan desert dust in Asia is prevalent in the TOMS record during spring, and eastern Siberian smoke from boreal forest fires is prevalent during summer. Aerosol trends are calculated on a regional basis during winter (November–February) to maximize the anthropogenic component of the aerosol record. Large increases in aerosol optical depths between 1979 and 2000 are present over the China coastal plain and the Ganges River basin in India. Aerosol increased by 17% per decade during winter over the China coastal plain, while SO2 emissions over the same geographical region increased by 35% per decade.

New paleomagnetic paleolatitudes for the Omulevka terrane of northeast Russia: a comparison with the Omolon terrane and the eastern Siberian platform

Paleomagnetic measurements were made on samples from Silurian, Devonian, Carboniferous and Permian aged rocks from the Omulevka terrane, northeast Russia. The Omulevka terrane is a fragment of continental margin that forms a major component of the Kolyma–Omolon superterrane, a superterrane that constitutes the core of northeast Russia. All samples were collected from sites along the Taskan river, and all showed a very strong secondary overprint and in some cases more than one. With detailed thermal demagnetization, a component of magnetization that decayed towards the origin when viewed as an orthogonal plot was commonly present and showed better clustering of magnetization directions in stratigraphic coordinates. All of the sites sampled were tilted, but none had enough variation in bedding attitude to perform fold tests. Comparing data between localities was used as a pseudo fold test and indicates that in all but one case the characteristic remanent magnetization found represents a magnetization acquired very early in the history of the rock. Interpretation of these data in terms of both virtual pole positions and paleolatitude changes with time shows that the Omulevka terrane and the adjacent Omolon terrane were together at low latitudes in Silurian and Devonian time and until late Devonian their latitude was consistent with them being closely related to the Siberian Craton. Between Devonian and Permian times, the paleolatitudes of the terranes decreased and, when compared with equivalent reference paleolatitudes for the nearby Siberian platform, show a clear latitudinal separation. From Permian to Jurassic time, the Omulevka and Omolon terranes move steadily northwards, reducing the relative latitudinal separation from Siberia. By late Jurassic to early Cretaceous time, the observed and equivalent Siberian paleolatitudes are identical, indicating the accretion of the Kolyma–Omolon superterrane to the eastern Siberian continent.

Comparative Phylogenetic Study of Native North Eurasian Populations Using a Panel of Autosomal Microsatellite Loci

Genetic relationships among eighth Siberian and Central Asian ethnic groups were examined using autosomal microsatellite loci. Genetic similarity of Buryats and Evenks, as well as close relationships between Tuvinians and Kyrgyzes, most likely resulting from the Altai-Slavic co-ancestry of their gene pools, was demonstrated. Studies of gene flow in these populations demonstrated that, in general, Turkic ethnic groups of Southern Siberia (Altaians and Tuvinians) were the recipients of more intense gene flow compared to Eastern Siberian populations belonging to Altaic family. The local Buryat populations displayed substantial differences in the direction and the level of deviation of the observed gene diversity from the expected one, which was probably caused by the differences in the degree of isolation and/or in effective population sizes.

Reconstruction of ice complex remnants on the eastern Siberian arctic shelf

AbstractBased on the analysis of seafloor topography together with historical, geological and palaeogeographical data obtained from published and archived sources, the position of former Ice Complex (IC) islands has been reconstructed. Within the Laptev Sea shelf and in the western part of the East Siberian Sea shelf, most of these islands have been destroyed by coastal thermal erosion and thermal abrasion during the last thousand years or so. The IC islands were the remnants of the ice‐rich syncryogenic freshwater terrestrial deposits (so called IC), which covered most of the arctic coastal plains and the emerged arctic shelf during the Late Pleistocene. At the present time, sandbanks exist at the places of former IC islands. These sandbanks are the subject of intense seafloor thermal abrasion. The approximate rates of seafloor thermal abrasion and the time of complete disappearance of these islands during the last thousand years have been estimated. The rate is different for different islands and for different time intervals. The most common values are between 0.02 and 0.3 m/year. Schematic maps of the former IC islands within the Laptev Sea and western part of the East Siberian Sea shelves have been compiled. Copyright © 2003 John Wiley & Sons, Ltd.

Accumulation patterns of polychlorinated biphenyl congeners and organochlorine pesticides in Steller's sea eagles and white-tailed sea eagles, threatened species, in Hokkaido, Japan

Polychlorinated biphenyls (PCBs), including coplanar congeners, hexachlorocyclohexane isomers, chlordane-related compounds, and hexachlorobenzene, were found in the breast muscle of Steller's sea eagles (SSE) and white-tailed sea eagles (WSE) threatened species, collected in Hokkaido, Japan, during the two years from 1998 to 1999. Both PCBs and DDTs were the most notable compounds, with concentrations one to two orders of magnitude higher than the other compounds, that is, from 120 to 39,000 and from 68 to 15,000 ng/g wet weight, respectively. Non-ortho (International Union of Pure and Applied Chemistry [IUPAC] 77, 126, and 169) and mono-ortho (IUPAC 105, 118, and 156)-substituted coplanar PCB congeners amounted to 9.2 to 740 pg/g of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents derived from the World Health Organization, Paris, France (WHO), toxic equivalent factors. The atmospheric PCBs and DDTs in eastern Siberian cities, such as Khabarovsk and Magadan, have been reported to be much higher than Hokkaido and the North Pacific. Thus, we speculated that the eagles might have been contaminated in these areas, where they spend most of the year except winter, which they spend in eastern Siberia. Adult eagles accumulated more PCBs and DDTs than younger ones. The patterns of PCB congeners were also found to change, depending on the age of the eagle examined; adult eagles showed relatively higher proportions of highly chlorinated PCBs than juvenile eagles did. This difference would be related to the efficiency of the excretion and the metabolism of each PCB congener in the eagles.

Accumulation patterns of polychlorinated biphenyl congeners and organochlorine pesticides in Steller's sea eagles and white-tailed sea eagles, threatened species, in Hokkaido, Japan.

Polychlorinated biphenyls (PCBs), including coplanar congeners, hexachlorocyclohexane isomers, chlordane-related compounds, and hexachlorobenzene, were found in the breast muscle of Steller's sea eagles (SSE) and white-tailed sea eagles (WSE) threatened species, collected in Hokkaido, Japan, during the two years from 1998 to 1999. Both PCBs and DDTs were the most notable compounds, with concentrations one to two orders of magnitude higher than the other compounds, that is, from 120 to 39,000 and from 68 to 15,000 ng/g wet weight, respectively. Non-ortho (International Union of Pure and Applied Chemistry [IUPAC] 77, 126, and 169) and mono-ortho (IUPAC 105, 118, and 156)-substituted coplanar PCB congeners amounted to 9.2 to 740 pg/g of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents derived from the World Health Organization, Paris, France (WHO), toxic equivalent factors. The atmospheric PCBs and DDTs in eastern Siberian cities, such as Khabarovsk and Magadan, have been reported to be much higher than Hokkaido and the North Pacific. Thus, we speculated that the eagles might have been contaminated in these areas, where they spend most of the year except winter, which they spend in eastern Siberia. Adult eagles accumulated more PCBs and DDTs than younger ones. The patterns of PCB congeners were also found to change, depending on the age of the eagle examined; adult eagles showed relatively higher proportions of highly chlorinated PCBs thanjuvenile eagles did. This difference would be related to the efficiency of the excretion and the metabolism of each PCB congener in the eagles.

The origin and flux of icebergs released into the Last Glacial Maximum Northern Hemisphere oceans: the impact of ice‐sheet topography

AbstractThe precipitation fields of a palaeoatmospheric general circulation model are used to derive estimates of the geographical distribution, and flux, of icebergs from the Laurentide, Fennoscandinavian and eastern Siberian ice‐sheets at the Last Glacial Maximum (LGM). The atmospheric model fields from LGM simulations using CLIMAP or Peltier (ICE‐4G) ice orography were studied, to test the sensitivity of the predicted flux. The estimated Northern Hemispheric LGM iceberg flux is 3500–4000 km3 yr−1, of which about 60% issued directly into the North Atlantic. The iceberg flux from the St Lawrence area is of similar significance to that issuing from Hudson Strait in all estimates. Both the North Pacific and the Arctic received substantial iceberg fluxes (ca. 700 km3 yr−1), with relatively minor differences occurring between the two ice‐sheet reconstructions. Apparent discrepancies between Arctic deep‐sea core samples of ice‐rafted debris and our estimates of mean glacial iceberg flux may be ascribed to coastal trapping of bergs, the existence of floating ice tongues or a rapid exit of icebergs from the Arctic basin into the Greenland Sea through the Fram Strait. Copyright © 2001 John Wiley & Sons, Ltd.

Seasonal variation in the energy and water exchanges above and below a larch forest in eastern Siberia

AbstractThe water and energy exchanges in forests form one of the most important hydro‐meteorological systems. There have been far fewer investigations of the water and heat exchange in high latitude forests than of those in warm, humid regions. There have been few observations of this system in Siberia for an entire growing season, including the snowmelt and leaf‐fall seasons. In this study, the characteristics of the energy and water budgets in an eastern Siberian larch forest were investigated from the snowmelt season to the leaf‐fall season. The latent heat flux was strongly affected by the transpiration activity of the larch trees and increased quickly as the larch stand began to foliate. The sensible heat dropped at that time, although the net all‐wave radiation increased. Consequently, the seasonal variation in the Bowen ratio was clearly ‘U’‐shaped, and the minimum value (1·0) occurred in June and July. The Bowen ratio was very high (10–25) in early spring, just before leaf opening. The canopy resistance for a big leaf model far exceeded the aerodynamic resistance and fluctuated over a much wider range. The canopy resistance was strongly restricted by the saturation deficit, and its minimum value was 100 s m−1 (10 mm s−1 in conductance). This minimum canopy resistance is higher than values obtained for forests in warm, humid regions, but is similar to those measured in other boreal conifer forests. It has been suggested that the senescence of leaves also affects the canopy resistance, which was higher in the leaf‐fall season than in the foliated season. The mean evapotranspiration rate from 21 April 1998 to 7 September 1998 was 1·16 mm day−1, and the maximum rate, 2·9 mm day−1, occurred at the beginning of July. For the growing season from 1 June to 31 August, this rate was 1·5 mm day−1. The total evapotranspiration from the forest (151 mm) exceeded the amount of precipitation (106 mm) and was equal to 73% of the total water input (211 mm), including the snow water equivalent. The understory evapotranspiration reached 35% of the total evapotranspiration, and the interception evaporation was 15% of the gross precipitation. The understory evapotranspiration was high and the interception evaporation was low because the canopy was sparse and the leaf area index was low. Copyright © 2001 John Wiley & Sons, Ltd.

Chromosomal evolution of the Common Shrew Sorex araneus L.from the Southern Ural and Siberia in the postglacial period

This paper summarizes a series of studies on chromosomal geography of the common shrew Sorex araneus L. in Siberia and the Southern Urals. Chromosomal races inhabiting the Southern Urals and the Western Siberian Plain sequentially replace each other in the latitudinal direction. In this region, karyotypes of each two adjacent races differ from each other by a single whole-arm reciprocal translocation. In the Eastern Siberian branch, the neighboring races differ mainly in the number or set of metacentric chromosomes. Analysis of the race distribution in the common shrew in the context of paleophysiology of the glacial period allowed us to reconstruct the sequence of events leading to the establishment of the present-day structure of the species.

Potential analogues for paleoclimatic variations in eastern interior Alaska during the past 14,000 yr: atmospheric-circulation controls of regional temperature and moisture responses

The paleoclimatic history of a region can be viewed as a series of surface temperature and moisture anomalies through time. The effects of changes in large-scale climatic controls (e.g., insolation, major circulation controls) can be mediated by the influence of smaller-scale controls (e.g., topographic barriers, coastlines); this may result in heterogenous surface climatic responses at the regional and sub-regional scale. Divergent paleoclimatic trajectories between regions may be explainable in terms of such meso-scale patterns. Using modern analogues for paleoclimate we examine how the sequence of climatic variations in eastern interior Alaska during the interval 12,000–0 14 C yr BP could have been generated by specific atmospheric circulation patterns. Fossil-pollen and lake-level records document the long-term trends in temperature and effective moisture for the region. Water-balance modelling provides additional estimates of paleoprecipitation. Synoptic climatological patterns are described using the modern (instrumental) record of upper-level and sea-level pressure, surface temperature, and precipitation. At 12,000 14 C yr BP, eastern interior Alaska was cooler and drier than present, a situation generated today by a southward displacement of the jet stream. Conditions warmer and drier than present at 9000 14 C yr BP may have been generated by increased ridging north of Alaska and a weakened westerly circulation. Warmer, wetter conditions than present possibly prevailed in the late-middle Holocene; these might reflect ridging over Alaska and troughing further west. Cool, wet conditions feature enhanced westerly flow into Alaska through an eastward shift in the east Asian trough and positive pressure anomalies in the North Pacific; they may be analogous to cold periods of the Little Ice Age. The analogues demonstrate how surface conditions in other parts of Beringia may sometimes be similar to, while at other times different from those in the eastern interior. These broader spatial patterns provide hypotheses about past climates that can be tested with paleoclimatological data. For example, the widespread positive temperature anomalies associated with the warm/dry (9000 14 C yr BP) analogue fit with the expansion northward of the eastern Siberian treeline. The anomalously cool conditions in northeast Siberia associated with the warm/wet analogue may explain the continued (late-middle Holocene) treeline advance in Alaska while there was retreat in Siberia.

Terminal Pleistocene—Early Holocene occupation in northeast Asia and the Zhokhov assemblage

A knowledge of the history of ancient human occupation in the eastern Siberian Arctic differs distinctly from that of areas south of the Arctic Circle, where numerous sites are located (Fig. 1). A study of the latter provided a basis for a framework of cultural development, which was later applied to the archaeological materials of the arctic regions of eastern Siberia. Accordingly, the ideas on the chronology and the cultural interpretation of the northern sites are based essentially on the southern materials. The number of sites representing different stages of the Polar Stone Age is extremely small compared to that of the southern regions. If there are some dozens of Neolithic sites in the continental regions of the East Siberian Arctic, the early sites are significantly rare. Thus, there are very few sites presumed to be of the Dyuktai or Sumnagin culture, and the connection of these sites with the Late Paleolithic (or the Mesolithic) culture is rather questionable. The Late Pleistocene stage of human occupation of northeast Asia is considered to be related to a spreading and development of the Paleolithic Dyuktai culture.

Evolution and biogeography of the woody Hawaiian violets (Viola, Violaceae): arctic origins, herbaceous ancestry and bird dispersal.

Specialists studying the genus Viola have consistently allied the Hawaiian violets comprising section Nosphinium--most of which are subshrubs or treelets--with putatively primitive subshrubs in certain South American violet groups. Hawaiian violets also possess inflorescences, a floral disposition otherwise found only in other genera of the Violaceae, thus strengthening the hypothesis of a very ancient origin for the Hawaiian species. A survey of phylogenetic relationships among infrageneric groups of Viola worldwide using nuclear rDNA internal transcribed spacer (ITS) sequences revealed a dramatically different biogeographic origin for the Hawaiian violets: A monophyletic Hawaiian clade was placed in a close sister relationship with the amphi-Beringian tundra violet, V. langsdorffii s. 1., in a highly derived position. This remarkable and unforeseen relationship received strong clade support values across analyses, and monophyly of the Hawaiian lineage was further indicated by a unique 26-base-pair deletion in section Nosphinium. The high polyploid base chromosome number (n approximately equal to 40) in the Hawaiian violets relates them to Alaskan and eastern Siberian populations in the polyploid V. langsdorffii complex. More than 50 species of the 260 allochthonous birds wintering in the Hawaiian Islands are found to breed in the Arctic, occupying habitats in which individual birds might have encountered ancestral V. langsdorffii populations and served as dispersers to the central Pacific region. Acquisition of derived morphological traits (e.g., arborescence and inflorescences), significance of a confirmed Arctic origin for a component of the Hawaiian flora, and the likelihood of other "cryptic" Arctic elements in the Hawaiian flora deserving independent molecular phylogenetic corroboration are discussed.

Song variation in an avian ring species.

Divergence of mating signals can occur rapidly and be of prime importance in causing reproductive isolation and speciation. A ring species, in which two reproductively isolated taxa are connected by a chain of intergrading populations, provides a rare opportunity to use spatial variation to reconstruct the history of divergence. I use geographic variation in the song of a likely ring species, the greenish warbler (Phylloscopus trochiloides) to reconstruct the microevolutionary steps that occurred during divergence of a trait that is often important in speciation in birds. Populations of a western Siberian (P. t. viridanus) and an eastern Siberian (P. t. plumbeitarsus) form of the greenish warbler meet, but do not interbreed in central Siberia; these forms are connected by a chain of interbreeding populations extending in a ring to the south around the treeless Tibetan Plateau. I show that: (1) song structure differs greatly between the two Siberian forms, which share the same habitat; (2) song structure changes gradually around the ring; (3) singing behavior is relatively simple in the Himalayas, but becomes increasingly complex to the north, both to the west and east of the Tibetan Plateau; and (4) song varies along independent axes of complexity in the western and eastern south-north clines. By comparing geographic variation in singing behavior and ecological variables, I distinguish among possible causes of song divergence, including selection based on the acoustic environment, stochastic effects of sexual selection, and selection for species recognition. I suggest that parallel south-to-north ecological gradients have caused a greater intensity of sexual selection on song in northern populations and that the stochastic effects of sexual selection have led to divergence in song structure.

Riverine fluxes of the persistent organochlorine pesticides hexachlorcyclohexane and DDT in the Russian Federation

The contribution of gross riverine organochlorine pesticide (OCP) transport to estuaries of Russian seas and Lake Baikal was determined to help understand OCP transboundary transfer and to provide a basis for estimating Russia's contribution to global pollution by these pesticides. The official OGSNK/GSN data ranks sea/ocean/lake basins in the following order based upon the amounts of total OCPs received from agricultural use: Eastern Arctic>Western Arctic>Pacific>Baltic>Caspian>Azov/Black>Baikal. A similar ranking was obtained using an independent set of data: Eastern Arctic>Pacific>Caspian>Western Arctic>Baltic>Azov/Black. In terms of riverine flow-associated discharge of HCH isomers (i.e., sum of α-, β- and γ-HCH) estuaries of the Kara, Okhotsk and Beloye (White)/Barents seas received more pesticides than other seas. No HCH was discharged to estuaries of the Eastern Siberian and Bering seas. For DDT and its derivative (DDE), estuaries of the Kara, Caspian, Okhotsk and Baltic seas received the greatest amounts. During our study period (1988–1996), HCH transport was more prevalent in the majority of rivers reflecting both the official ban on the use of DDT in the former Soviet Union and the greater popularity of HCH as a pesticide. In general, it appears that Russian rivers play a significant role in OCP contamination of some estuaries of regional seas, especially those of the eastern Arctic basin, such as the Kara Sea.

SONG VARIATION IN AN AVIAN RING SPECIES

Divergence of mating signals can occur rapidly and be of prime importance in causing reproductive isolation and speciation. A ring species, in which two reproductively isolated taxa are connected by a chain of intergrading populations, provides a rare opportunity to use spatial variation to reconstruct the history of divergence. I use geographic variation in the song of a likely ring species, the greenish warbler (Phylloscopus trochiloides) to reconstruct the microevolutionary steps that occurred during divergence of a trait that is often important in speciation in birds. Populations of a western Siberian (P. t. viridanus) and an eastern Siberian (P. t. plumbeitarsus) form of the greenish warbler meet, but do not interbreed in central Siberia; these forms are connected by a chain of interbreeding populations extending in a ring to the south around the treeless Tibetan Plateau. I show that: (1) song structure differs greatly between the two Siberian forms, which share the same habitat; (2) song structure changes gradually around the ring; (3) singing behavior is relatively simple in the Himalayas, but becomes increasingly complex to the north, both to the west and east of the Tibetan Plateau; and (4) song varies along independent axes of complexity in the western and eastern south-north clines. By comparing geographic variation in singing behavior and ecological variables, I distinguish among possible causes of song divergence, including selection based on the acoustic environment, stochastic effects of sexual selection, and selection for species recognition. I suggest that parallel south-to-north ecological gradients have caused a greater intensity of sexual selection on song in northern populations and that the stochastic effects of sexual selection have led to divergence in song structure.Corresponding Editor: S. Edwards

Mitochondrial DNA variation in Koryaks and Itel'men: population replacement in the Okhotsk Sea-Bering Sea region during the Neolithic.

In this study, we analyzed the mitochondrial DNA (mtDNA) variation in 202 individuals representing one Itel'men and three Koryak populations from different parts of the Kamchatka peninsula. All mtDNAs were subjected to high resolution restriction (RFLP) analysis and control region (CR) sequencing, and the resulting data were combined with those available for other Siberian and east Asian populations and subjected to statistical and phylogenetic analysis. Together, the Koryaks and Itel'men were found to have mtDNAs belonging to three (A, C, and D) of the four major haplotype groups (haplogroups) observed in Siberian and Native American populations (A-D). In addition, they exhibited mtDNAs belonging to haplogroups G, Y, and Z, which were formerly called "Other" mtDNAs. While Kamchatka harbored the highest frequencies of haplogroup G mtDNAs, which were widely distributed in eastern Siberian and adjacent east Asian populations, the distribution of haplogroup Y was restricted within a relatively small area and pointed to the lower Amur River-Sakhalin Island region as its place of origin. In contrast, the pattern of distribution and the origin of haplogroup Z mtDNAs remained unclear. Furthermore, phylogenetic and statistical analyses showed that Koryaks and Itel'men had stronger genetic affinities with eastern Siberian/east Asian populations than to those of the north Pacific Rim. These results were consistent with colonization events associated with the relatively recent immigration to Kamchatka of new tribes from the Siberian mainland region, although remnants of ancient Beringian populations were still evident in the Koryak and Itel'men gene pools.

Leaf conductance and CO(2) assimilation of Larix gmelinii growing in an eastern Siberian boreal forest.

In July 1993, we measured leaf conductance, carbon dioxide (CO(2)) assimilation, and transpiration in a Larix gmelinii (Rupr.) Rupr. ex Kuzen forest in eastern Siberia. At the CO(2) concentration of ambient air, maximum values (mean of 10 highest measured values) for CO(2) assimilation, transpiration and leaf conductance for water vapor were 10.1 micro mol m(-2) s(-1), 3.9 mmol m(-2) s(-1) and 365 mmol m(-2) s(-1), respectively. The corresponding mean values, which were much lower than the maximum values, were 2.7 micro mol m(-2) s(-1), 1.0 mmol m(-2) s(-1) and 56 mmol m(-2) s(-1). The mean values were similar to those of Vaccinium species in the herb layer. The large differences between maximum and actual performance were the result of structural and physiological variations within the tree crowns and between trees that reduced maximum assimilation and leaf conductance by about 40 and 60%, respectively. Thus, maximum assimilation and conductance values averaged over the canopy were 6.1 micro mol m(-2) s(-1) and 146 mmol m(-2) s(-1), respectively. Dry air caused stomatal closure, which reduced assimilation by an additional 26%. Low irradiances in the morning and evening had a minor effect (-6%). Daily canopy transpiration was estimated to be 1.45 mm day(-1), which is higher than the value of 0.94 mm day(-1) measured by eddy covariance, but similar to the value of 1.45 mm day(-1) calculated from the energy balance and soil evaporation, and less than the value of 2.1 mm day(-1) measured by xylem flux. Daytime canopy carbon assimilation, expressed on a ground area basis, was 0.217 mol m(-2) day(-1), which is higher than the value measured by eddy flux (0.162 mol m(-2) day(-1) including soil respiration). We discuss the regulation of leaf gas exchange in Larix under the extreme climatic conditions of eastern Siberia (temperature > 35 degrees C and vapor pressure deficit > 5.0 kPa).

Evaporation from an eastern Siberian larch forest

Total forest evaporation ( λE), understorey evaporation, and environmental variables were measured on nine summer days under different weather conditions in a 130-year-old stand of Larix gmelinii (Rupr.) Rupr. trees located 160 km south of Yakutsk in eastern Siberia, Russia (61°N, 128°E, 300m above sea-level (a.s.l.)). Tree and broad-leaved understorey vegetation one-sided leaf area indices were 1.5 and 1.0, respectively. Agreement of λE and sensible heat flux ( H), both measured by eddy covariance, and the available energy ( R a) was generally good: ( H + λE) = 0.83 R a + 9 W m −2 with r 2 = 0.92 for 364 half-hour periods and the mean ± 95% confidence limit was 129 ± 17 for ( H + λE) and 144 ± 19 for R a. Daily E was 1.6–2.2 min, less than half of the potential evaporation rate and accounting for 31–50% of R a, with the lowest percentage on clear days. A perusal of the sparse literature revealed that average daily E of boreal coniferous forest during the tree growing season (1.9 mm day −1 for this study) is relatively conservative, suggesting that low evaporation rates are a feature of this biome's energy balance. Using the Penman-Monteith equation, the maximum bulk-surface conductance ( G smax) was 10 mm s −1. E and G s were regulated by irradiance, air saturation deficit, and surface soil water content during a week-long dry period following 20 mm rainfall. From lysimeter measurements, 50% of E emanated from the understorey at a rate proportional to R a. Based on the measurements and published climatological data, including average annual precipitation equal to 213 mm, water balance calculations indicated growing season forest E equal to 169 mm, the occurrence of a late summer-autumn soil water deficit, and annual runoff of 44 mm by snowmelt.

Characteristics of the Alpine Flora of the Tokinskyi Stanovik Mountains, Southeastern Siberia in Relation to the Japanese Alpine and Eastern Siberian Arctic Floras

Characteristics of the Alpine Flora of the Tokinskyi Stanovik Mountains, Southeastern Siberia in Relation to the Japanese Alpine and Eastern Siberian Arctic Floras

Early summer temperatures since 1670 A.D. for Central Kamchatka reconstructed based on a Siberian larch tree-ring width chronology

A tree-ring width chronology of larch (Larixkurilensis Mayr) has been developed from along the Bystraya River near Esso in the interior valley of the Kamchatka Peninsula, Russia. The chronology, which covers from 1670 to 1992, explains 38% of the variance in May–June temperatures for the Esso meteorological station. This ring-width series is used to develop the first dendroclimatic reconstruction for Kamchatka. We caution that the Esso station record, the closest to the tree-ring site, is only 42 years in length, making model verification difficult. Periods of above-average temperatures are inferred for ca. 1750, 1800, and over the last few decades; colder than average conditions are inferred for 1710–1720, 1760–1770s, and 1860–1880s. The ring-width chronology cross-dates with other larch tree-ring data for Kamchatka and, during certain intervals, with a larch ring-width record from eastern Siberia. Comparison of the two records suggests that the insertion of a missing ring for the year 1816 in the eastern Siberian series is not justified. A birch (Betulaermanii Cham.) chronology from a coastal site near Petropavlovsk-Kamchatskiy correlates with July–August temperatures. Both the larch and more widespread birch species show promise for further dendroclimatic studies in Kamchatka.