scholarly journals Spatial-temporal dynamics of tree line in the Southern Siberia Mountains

2020 ◽  
Author(s):  
A.S. Golyukov ◽  
◽  
A.S. Shushpanov ◽  
I.A. Petrov ◽  
◽  
...  
Keyword(s):  
Air Temperature ◽  
Significant Relationship ◽  
Boreal Forests ◽  
Temporal Dynamics ◽  
Climatic Changes ◽  
Tree Line ◽  
Southern Siberia ◽  
Advance Rate

In recent decades, the tree line has been moving along the entire territory of the boreal forests due to climatic changes. In this work, the dynamics of the tree line and the area of closed stands in the Southern Siberian Mountains are analyzed. At all objects of the study, the advancement of the tree line is observed with an average advance rate of ~ 0.6 – 0.9 m per year. A significant relationship was found between the advancement of the tree line and the air temperature.

Tree line shifts, changing vegetation assemblages and permafrost dynamics on Galdhøpiggen (Jotunheimen, Norway) over the past ~4400 years

The Holocene ◽  
2021 ◽  
pp. 095968362110665
Author(s):  
Helen Hallang ◽  
Cynthia A Froyd ◽  
John F Hiemstra ◽  
Sietse O Los
Keyword(s):  
Scots Pine ◽  
Late Holocene ◽  
Accumulation Rate ◽  
Climatic Changes ◽  
Climatic Conditions ◽  
Tree Line ◽  
Peat Core ◽  
Modern Pollen ◽  
Modern Analogue ◽  
Downy Birch

An environmental reconstruction based on palynological evidence preserved in peat was carried out to examine late-Holocene alpine tree line dynamics in the context of past climatic changes on Galdhøpiggen (Jotunheimen, southern Norway). We analysed a peat core taken from a mire at the present-day tree line (1000 m a.s.l.), c. 450 m downslope from the lower limit of sporadic permafrost. We adopted a combination of commonly used indicators of species’ local presence to reconstruct past vegetation assemblages, such as the relative pollen abundance (%), pollen accumulation rate (PAR), and presence of indicator species. Additionally, fossil pollen from the peat sequence was compared to modern pollen from a surface moss polster to establish a modern analogue. The results were compared with studies covering the late-Holocene climatic changes in the area. The reconstruction demonstrates that a pine-dominated woodland reached above the present-day tree line at c. 4300 cal. yr BP, suggesting a warmer climate suitable for Scots pine ( Pinus sylvestris) growth at this altitude. Scots pine retreated to lower altitudes between c. 3400 and 1700 cal. yr BP, accompanied by the descent of the low-alpine shrub-dominated belt, in response to cooling climatic conditions. The colder period covered c. 1700–170 cal. yr BP, and an open downy birch ( Betula pubescens) woodland became widespread at 1000 m a.s.l., whilst pine remained sparse at this altitude. From c. 170 cal. yr BP onwards, warming allowed pine to re-establish its local presence alongside downy birch at 1000 m a.s.l.

scholarly journals Climatic changes and their influence on air temperature and precipitation in Ukraine during transitional seasons

2020 ◽  
pp. 60-67
Author(s):  
V. M. Khokhlov ◽  
H. O. Borovska ◽  
M. S. Zamfirova
Keyword(s):  
Air Temperature ◽  
Meteorological Parameters ◽  
Regional Climate ◽  
Monitoring Network ◽  
Climatic Changes ◽  
Precipitation Regime ◽  
Runoff Water ◽  
The West ◽  
Temperature And Precipitation ◽  
Dynamic Methods

      Since modern research indicates climatic changes in all regions of our planet, including on the territory of Ukraine (in particular, the deviation of temperature and other meteorological parameters from the values of the climatic norm), their study is extremely important. After all, they can lead to changes in the nature of precipitation distribution, the length of the growing season, a decrease in the duration of the stable snow cover, local runoff water resources, etc. Most scientific works in recent years describe changes in the distribution of temperature characteristics and precipitation regime, because they are one of the main indicators of the state of the climate system. Therefore, the purpose of this article is to identify the features of changes in air temperature and precipitation for the entire territory of Ukraine from 2021 to 2050 based on the results of 16 simulations of the ensemble of CORDEX models based on the RCP4.5 scenario. The CORDEX project is a modern simulation of the future climate and has a resolution of ~ 12.5 km in the horizontal plane, which makes it possible to better simulate the characteristics under study. It integrates regional climate predictions that are generated using statistical and dynamic methods. The results obtained are presented for 177 cities of Ukraine, which currently form the basis of a modern monitoring network. It was found that the number of days with precipitation ≥ 5 mm in transitional seasons increases on average by 1-3 days per month, depending on the region. The maximum values of the frequency of occurrence of the number of days with precipitation ≥ 5 mm are observed in the west and gradually decrease in the south. Compared to 1961-1990, the most significant changes occur with the number of frosty days with an air temperature of ≤ 0°С, which noticeably decreases during the study period from north to south. In April and October, for the southern regions of Ukraine, the considered parameter is equal to 0, which means that in these months the air temperature for these regions will have positive values. From the above, there is a tendency towards warming in transitional seasons and a change in the nature of moisture supply to the territory of Ukraine in the next thirty years.

scholarly journals Spatial–temporal dynamics of chemical composition of surface snow in East Antarctica along the Progress station–Vostok station transect

2014 ◽  
Vol 8 (3) ◽  
pp. 931-939 ◽  
Author(s):  
T. V. Khodzher ◽  
L. P. Golobokova ◽  
E. Yu. Osipov ◽  
Yu. A. Shibaev ◽  
V. Ya. Lipenkov ◽  
...  
Keyword(s):  
Significant Relationship ◽  
High Performance ◽  
Temporal Dynamics ◽  
Accumulation Rate ◽  
Middle Part ◽  
East Antarctica ◽  
Time Interval ◽  
Slope Gradient ◽  
Volcanic Origin ◽  
Surface Snow

Abstract. In January of 2008, during the 53rd Russian Antarctic Expedition, surface snow samples were taken from 13 shallow (0.7 to 1.5 m depth) snow pits along the first tractor traverse from Progress to Vostok stations, East Antarctica. Sub-surface snow/firn layers are dated from 2.1 to 18 yr. The total length of the coast to inland traverse is more than 1280 km. Here we analysed spatial variability of concentrations of sulphate ions and elements and their fluxes in the snow deposited within the 2006–2008 time interval. Anions were analysed by high-performance liquid chromatography (HPLC), and the determination of selected metals, including Na, K, Mg, Ca and Al, was carried out by mass spectroscopy with atomization by induced coupled plasma (ICP-MS). Surface snow concentration records were examined for trends versus distance inland, elevation, accumulation rate and slope gradient. Na shows a significant positive correlation with accumulation rate, which decreases as distance from the sea and altitude increase. K, Ca and Mg concentrations do not show any significant relationship either with distance inland or with elevation. Maximal concentrations of these elements with a prominent Al peak are revealed in the middle part of the traverse (500–600 km from the coast). Analysis of element correlations and atmospheric circulation patterns allow us to suggest their terrestrial origin (e.g. aluminosilicates carried as a continental dust) from the Antarctic nunatak areas. Sulphate concentrations show no significant relationship with distance inland, elevation, slope gradient and accumulation rate. Non-sea salt secondary sulphate is the most important contribution to the total sulphate budget along the traverse. Sulphate of volcanic origin attributed to the Pinatubo eruption (1991) was revealed in the snow pit at 1276 km (depth 120–130 cm).

Oxygen isotope compositions of phosphate from arvicoline teeth and Quaternary climatic changes, Gigny, French Jura

2004 ◽  
Vol 62 (2) ◽  
pp. 172-182 ◽  
Author(s):  
Nicolas Navarro ◽  
Christophe Lécuyer ◽  
Sophie Montuire ◽  
Cyril Langlois ◽  
François Martineau
Keyword(s):  
Oxygen Isotope ◽  
Air Temperature ◽  
Isotope Fractionation ◽  
Meteoric Water ◽  
Ice Core ◽  
Climatic Changes ◽  
Oxygen Isotope Fractionation ◽  
Air Temperatures ◽  
French Jura ◽  
Fractionation Equation

Oxygen isotope compositions of biogenic phosphates from mammals are widely used as proxies of the isotopic compositions of meteoric waters that are roughly linearly related to the air temperature at high- and mid-latitudes. An oxygen isotope fractionation equation was determined by using present-day European arvicoline (rodents) tooth phosphate: δ18Op = 20.98(±0.59) + 0.572(±0.065) δ18Ow. This fractionation equation was applied to the Late Pleistocene karstic sequence of Gigny, French Jura. Comparison between the oxygen isotope compositions of arvicoline tooth phosphate and Greenland ice core records suggests to reconsider the previously established hypothetical chronology of the sequence. According to the δ18O value of meteoric water–mean air temperature relationships, the δ18O value of arvicoline teeth records variations in mean air temperatures that range from 0° to 15°C.

Spatial distribution and temporal dynamics of high-elevation forest stands in southern Siberia

2010 ◽  
Vol 19 (6) ◽  
pp. 822-830 ◽  
Author(s):  
Vyacheslav I. Kharuk ◽  
Kenneth J. Ranson ◽  
Sergey T. Im ◽  
Alexander S. Vdovin
Keyword(s):  
Spatial Distribution ◽  
Temporal Dynamics ◽  
High Elevation ◽  
Forest Stands ◽  
Southern Siberia ◽  
High Elevation Forest

Saproxylic beetles in disturbed boreal forests: Temporal dynamics, habitat associations, and community structure

Ecoscience ◽  
2012 ◽  
Vol 19 (4) ◽  
pp. 328-343 ◽  
Author(s):  
Jonathan Boucher ◽  
Ermias T. Azeria ◽  
Jacques Ibarzabal ◽  
Christian Hébert
Keyword(s):  
Community Structure ◽  
Boreal Forests ◽  
Temporal Dynamics ◽  
Habitat Associations ◽  
Saproxylic Beetles

Holocene paleoclimate and paleoecology determined from fossil Coleoptera at Brampton, Ontario, Canada

2001 ◽  
Vol 38 (10) ◽  
pp. 1451-1462 ◽  
Author(s):  
John E Motz ◽  
Alan V Morgan
Keyword(s):  
Environmental Conditions ◽  
Boreal Forests ◽  
Bark Beetles ◽  
Younger Dryas ◽  
Temperate Species ◽  
Fossil Insects ◽  
Tree Line ◽  
Holocene Paleoclimate ◽  
M Sequence ◽  
Cold Events

An unusually rich and extensive 5 m sequence of organic-rich sediments (ca. 13 000 to ca. 4500 BP) from a drained glacial kettle near Brampton, Ontario, has produced a large and varied assemblage of fossil insects. Coleoptera (beetles) from the base include species typical of northern boreal or tree line habitats today. Approximately one metre above the base of the section (ca. 11 500 BP), there is an abrupt appearance of numerous bark beetles (family Scolytidae) and other Coleoptera that inhabit boreal forests. Temperate species whose ranges are predominantly or totally south of the Ontario border, appear, beginning at ca. 9500 BP, suggesting environmental conditions similar to modern ones. Younger Dryas and Pre-Boreal Oscillation cold events may be evident in lower parts of the boreal sequence, although considerations of temporal and climatic resolution make interpretation somewhat ambiguous.

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