Aeolian processes in forest-steppe landscapes in the Upper Angara region in the Holocene.

2020 ◽  
Vol 41 (4) ◽  
pp. 381-389
Author(s):  
V. A. Golubtsov ◽  
M. Yu. Opekunova ◽  
F. E. Maksimov ◽  
A. Yu. Petrov

Radiocarbon ◽  
2002 ◽  
Vol 44 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Lyubov A Orlova ◽  
Valentina S Zykina

We have constructed a detailed chronological description of soil formation and its environments with data obtained on radiocarbon ages, palynology, and pedology of the Holocene buried soils in the forest steppe of western and central Siberia. We studied a number of Holocene sections, which were located in different geomorphic situations. Radiocarbon dating of materials from several soil horizons, including soil organic matter (SOM), wood, peat, charcoal, and carbonates, revealed three climatic periods and five stages of soil formation in the second part of the Holocene. 14C ages of approximately 6355 BP, 6020 BP, and 5930 BP showed that the longest and most active stage is associated with the Holocene Climatic Optimum, when dark-grey soils were formed in the forest environment. The conditions of birch forest steppe favored formation of chernozem and associated meadow-chernozem and meadow soils. Subboreal time includes two stages of soil formation corresponding to lake regressions, which were less intense than those of the Holocene Optimum. The soils of that time are chernozem, grassland-chernozem, and saline types, interbedded with thin peat layers 14C dated to around 4555 B P, 4240 BP and 3480 BP, and 3170 B P. Subatlantic time includes two poorly developed hydromorphic paleosols formed within inshore parts of lakes and chernozem-type automorphic paleosol. The older horizon was formed during approximately 2500–1770 BP, and the younger one during approximately 1640–400 B P. The buried soils of the Subatlantic time period also attest to short episodes of lake regression. The climate changes show an evident trend: in the second part of the Atlantic time period it was warmer and drier than at present, and in the Subboreal and Subatlantic time periods the climate was cool and humid.


CATENA ◽  
2019 ◽  
Vol 172 ◽  
pp. 619-633 ◽  
Author(s):  
Svetlana Sycheva ◽  
Olga Khokhlova ◽  
Polina Pushkina ◽  
Pavel Ukrainsky

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Chao Zhao ◽  
Xiaoqiang Li ◽  
Xinying Zhou ◽  
Keliang Zhao ◽  
Qing Yang

Pollen samples from peat sediments on the south bank of the Heilongjiang River in northern Northeast China (NE China) were analyzed to reconstruct the historical response of vegetation to climate change since 7800 cal yr BP. Vegetation was found to have experienced five successions from cold-temperate mixed coniferous and broadleaved forest to forest-steppe, steppe-woodland, steppe, and finally meadow-woodland. From 7800 to 7300 cal yr BP, the study area was warmer than present, andBetula, Larix, andPicea-dominated mixed coniferous and broadleaved forests thrived. Two cooling events at 7300 cal yr BP and 4500 cal yr BP led to a decrease inBetulaand other broadleaved forests, whereas herbs of Poaceae expanded, leading to forest-steppe and then steppe-woodland environments. After 2500 cal yr BP, reduced temperatures and a decrease in evaporation rates are likely to have resulted in permafrost expansion and surface ponding, with meadow and isolated coniferous forests developing a resistance to the cold-wet environment. The Holocene warm period in NE China (7800–7300 cal yr BP) could have resulted in a strengthening of precipitation in northernmost NE China and encouraged the development of broadleaved forests.


The Holocene ◽  
2016 ◽  
Vol 27 (7) ◽  
pp. 941-950 ◽  
Author(s):  
Robert D McCulloch ◽  
Maria J Figuerero Torres ◽  
Guillermo L Mengoni Goñalons ◽  
Rebecca Barclay ◽  
Claudia Mansilla

There are few continuous palaeoenvironmental records spanning the Holocene in Andean Southern Patagonia near the Northern Patagonian Ice Field (~47°S). Insights into the environmental context for human–landscape interactions have relied mostly on data extrapolated from distant extra-Andean locations that suggest limited environmental change during the Holocene. La Frontera (46°52′S), a high altitude site on the southern beech forest–steppe ecotone boundary in the Río Zeballos valley, provides lithostratigraphical and palaeoecological evidence, constrained by 14C dating and tephrochronology, for dynamic environmental change during the last ~8000 years. An initial amelioration in environmental conditions after c. 8210 cal. BP was followed by a reversal to colder conditions between c. 7420 and 6480 cal. BP, coincident with initial human occupation within the Paso Roballos and Lago Pueyrredón basin. Between c. 6480 and 3700 cal. BP, the woodland/steppe composition continued to fluctuate in response to climatic change. After c. 3700 cal. BP, a gradual shift to more stable and temperate conditions, punctuated by increased fire activity, is contemporary with the later phases of human occupation extending up into the Paso Roballos–Río Zeballos corridor.


2018 ◽  
Vol 65 (2) ◽  
pp. 109-122
Author(s):  
Ekaterina N. Badyukova ◽  
Leonid A. Zindarev ◽  
Svetlana A. Lukyanova ◽  
Galina D. Solovieva

AbstractThis article addresses the southern sector of the Curonian Spit, the largest coastal barrier of the Baltic Sea. A comparative analysis of the deposits that make up parts of the Curonian and Vistula Spits is given. The detailed analysis of the geological and geomorphological structure of the southern part of the Curonian Spit suggests that, within this sector, it is not a sedimentary barrier created by wave action and Aeolian processes in the Holocene, but a part of a pre-Holocene fluvioglacial plain. Field work has shown that the ancient alluvial or fluvioglacial plain is in the lagoon shore of the Vistula Spit.


10.12737/1790 ◽  
2013 ◽  
Vol 3 (3) ◽  
pp. 43-49
Author(s):  
Харченко ◽  
Nikolay Kharchenko ◽  
Харченко ◽  
Nikolay Kharchenko

The article contains a critical review of publications on the origin of oak forests in Central forest steppe.The article contains a critical review of publications on the origin of oak forests in Central forest steppe. Our hypothesis can not be considered mutually exclusive. The primacy of the steppe towards the forest is well recognized, as well as the reality of the periodic changes of plant com-munities within the natural areas in different chronological intervals of the Holocene. Sequential change of steppe vegetation formations for oak forest ones occurred depending on the global climate change. Intra-ecosystem successional processes are based on the biological characteristics of interacting tree species.


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