scholarly journals Multi-proxy reconstruction of mire development in the Poręby Wojsławskie ecosystem (Sandomierz Basin, southeastern Poland)

2013 ◽  
Vol 40 (3) ◽  
pp. 177-186
Author(s):  
Jacek Chodorowski ◽  
Andrzej Plak ◽  
Irena Pidek ◽  
Radosław Dobrowolski
Keyword(s):  
Water Supply ◽  
Human Impact ◽  
Radiocarbon Dating ◽  
Late Glacial ◽  
Geochemical Data ◽  
Pollen Diagram ◽  
The Holocene ◽  
Se Poland ◽  
Mire Ecosystem ◽  
Precipitation And Temperature

AbstractMulti-proxy analysis (sedimentological, palaeobotanical, geochemical data and results of radiocarbon dating) of the biogenic sediments from a small mire ecosystem in the Sandomierz Basin (SE Poland) is presented. The ecosystem contains a full hydroseral sequence from minerotrophic to ombrotrophic wetland. It is one of the few sites in this region which is so thoroughly investigated in terms of the palaeoenvironmental record. Changes in the water supply of the mire area, and consequently the changes in the plant and sediment succession, were well correlated with the regional tendencies in precipitation and temperature during the Late Glacial/Holocene transition and in the Holocene. Human impact is very well recorded in pollen diagram from the Subboreal period.

scholarly journals A major hydrobiological change in Dasht-e Arjan Wetland (southwestern Iran) during the late glacial – early Holocene transition revealed by subfossil chironomids

2019 ◽  
Vol 56 (8) ◽  
pp. 848-856
Author(s):  
Cyril Aubert ◽  
Morteza Djamali ◽  
Matthew Jones ◽  
Hamid Lahijani ◽  
Nick Marriner ◽  
...  
Keyword(s):  
Lake Level ◽  
Regional Scale ◽  
Younger Dryas ◽  
Late Glacial ◽  
Early Holocene ◽  
Geochemical Data ◽  
The Holocene ◽  
Chironomus Plumosus ◽  
Subfossil Chironomids ◽  
Southwestern Iran

The late glacial – early Holocene transition is a key period in the earth’s history. However, although this transition is well studied in Europe, it is not well constrained in the Middle East and palaeohydrological records with robust chronologies remain scarce from this region. Here we present an interesting hydrobiological record showing a major environmental change occurring in the Dasht-e Arjan Wetland (southwestern Iran, near to Persepolis) during the late glacial – early Holocene transition (ca. 11 650 years cal BP). We use subfossil chironomids (Insecta: Diptera) as a proxy for hydrological changes and to reconstruct lake-level fluctuations. The Arjan wetland was a deep lake during the Younger Dryas marked by a dominance of Chironomus plumosus/anthracinus-type, taxa adapted to anoxic conditions of deep waters. At the beginning of the Holocene, a drastic decrease (more than 80% to less than 10%) of Chironomus plumosus/anthracinus-type, combined with diversification of littoral taxa such as Polypedilum nubeculosum-type, Dicrotendipes nervosus-type, and Glyptotendipes pallens-type, suggests a lake-level decrease and a more vegetalized aquatic environment. We compare and contrast the chironomid record of Arjan with a similar record from northwestern Iran. The palaeoclimatic significance of the record, at a local and regional scale, is subsequently discussed. The increase in Northern Hemisphere temperatures, inferred by geochemical data from NGRIP, at the beginning of the Holocene best explains the change from the Younger Dryas highstand to early Holocene lowstand conditions in the Dasht-e Arjan wetland. However, a contribution of the meltwater inflow from small local glaciers in the catchment basin is not excluded.

scholarly journals Reconstruction of vegetation in the foothills of the Carpathian Mountains, Gorgany region, in the late glacial (based on pollen data of peat-bog Pidluzhia)

2015 ◽  
pp. 333-340
Author(s):  
Natalia Chumak
Keyword(s):  
Key Words ◽  
Radiocarbon Dating ◽  
Environmental Changes ◽  
Younger Dryas ◽  
Late Glacial ◽  
Peat Bog ◽  
Pollen Data ◽  
Carpathian Mountains ◽  
The Holocene ◽  
Short Period

The environmental changes on short-period stages of the Late Glacial were reconstructed based on pollen data of peat-bog Pidluzhia deposits and their radiocarbon dating. There are the Older and Younger Dryas, the Allerod (three phases) are allocated on palynological data in the Late Glacial. Vegetation had evolved from cold meadows to pine forest during this time. The transition from the Late Glacial to the Holocene was identified by the emergence of broad-leaved trees (elm, oak and linden), the spreading of spruce and disappearance of xerophytic elements. Key words: paleovegetation, paleoclimate, palinology, the Late Glacial, the foothills of the Carpathian Mountains.

A CARBON-DATED POLLEN DIAGRAM FROM THE CAPE BRETON PLATEAU, NOVA SCOTIA

1967 ◽  
Vol 45 (3) ◽  
pp. 339-359 ◽  
Author(s):  
D. A. Livingstone ◽  
A. H. Estes
Keyword(s):  
Nova Scotia ◽  
Radiocarbon Dating ◽  
Late Glacial ◽  
Pollen Diagram ◽  
Cape Breton ◽  
Poplar Trees ◽  
Glacial Time ◽  
Nova Scotian

Organic sedimentation in a lake near the southwestern edge of the Cape Breton Plateau began about 9000 years ago. Before that time the vegetation was an open tundra, probably with scattered conifer and poplar trees. Since then the vegetation has been dominated by closed fir forest of a variety of types not dissimilar to forests growing in various parts of Nova Scotia today. Organic sedimentation and the establishment of forest, and by implication deglaciation, began more recently at Wreck Cove Lake than at any other Nova Scotian locality that has been investigated. The establishment of forest occurred 1300 years sooner in part of lowland Cape Breton, and 1800 years sooner in part of mainland Nova Scotia, than it did on the Cape Breton Plateau. The length of postglacial, preforest time, which cannot be measured by radiocarbon dating, appears to have been much shorter at Wreck Cove than it was in lowland Cape Breton. The Cape Breton Plateau was not, as some phytogeographers have suggested, a nunatak during glacial time. It may have been a center of late-glacial readvance.

Postglacial evolution of a small lake in the South Baltic coastal zone based on geochemical, pollen and subfossil Cladocera analysis

2018 ◽  
Vol 47 (4) ◽  
pp. 384-397 ◽  
Author(s):  
Monika Niska ◽  
Joanna Gadziszewska ◽  
Jerzy Jonczak ◽  
Wacław Florek ◽  
Bogusława Kruczkowska
Keyword(s):  
Water Level ◽  
Late Glacial ◽  
Water Level Fluctuations ◽  
Geochemical Data ◽  
Peat Bogs ◽  
Subfossil Cladocera ◽  
Sedimentary Records ◽  
Pollen Content ◽  
Mire Ecosystem ◽  
Climate Fluctuation

Abstract The paper presents sedimentary records acquired as part of the research on the coastal cliff located between 221.3 and 221.4 km of the Slovincian (Słowinskie) Coast near Debina. Palynological and subfossil Cladocera analysis of sediments combined with geochemical data proves the existence of varying environmental conditions that occurred depending on the climate fluctuation. The Debina reservoir was formed in the Late Glacial period. Mud and gyttja were deposited in an initially cold proglacial lake. Species of Cladocera identified in this period indicate a deeper oligotrophic reservoir. The end of the Late Glacial cooling inhibited the development of fauna in the reservoir. Climate change at the beginning of the Holocene improved the habitat conditions in the Debina paleolake, which is reflected in the growth of zooplankton biodiversity and enrichment of the aquatic pollen content. We distinguished three phases that illustrate the evolution of the studied aquatic-mire ecosystem. In the following periods, the trophic level in the reservoir increased and significant water-level fluctuations led to periodic transformations of reservoirs into peat bogs. Gradually, the water-level lowering and the intensification of eolian processes led to terrestrialization of the paleolake.

scholarly journals Holocene vegetation, fire and land use dynamics at Lake Svityaz, an agriculturally marginal site in northwestern Ukraine

2021 ◽  
Author(s):  
Christoph Schwörer ◽  
Erika Gobet ◽  
Jacqueline F. N. van Leeuwen ◽  
Sarah Bögli ◽  
Rachel Imboden ◽  
...  
Keyword(s):  
Bronze Age ◽  
Human Impact ◽  
Central Europe ◽  
Large Scale ◽  
Mixed Forest ◽  
Fire Risk ◽  
Late Glacial ◽  
Future Climate Change ◽  
Agricultural Activity ◽  
Fire Dynamics

AbstractObserving natural vegetation dynamics over the entire Holocene is difficult in Central Europe, due to pervasive and increasing human disturbance since the Neolithic. One strategy to minimize this limitation is to select a study site in an area that is marginal for agricultural activity. Here, we present a new sediment record from Lake Svityaz in northwestern Ukraine. We have reconstructed regional and local vegetation and fire dynamics since the Late Glacial using pollen, spores, macrofossils and charcoal. Boreal forest composed of Pinus sylvestris and Betula with continental Larix decidua and Pinus cembra established in the region around 13,450 cal bp, replacing an open, steppic landscape. The first temperate tree to expand was Ulmus at 11,800 cal bp, followed by Quercus, Fraxinus excelsior, Tilia and Corylus ca. 1,000 years later. Fire activity was highest during the Early Holocene, when summer solar insolation reached its maximum. Carpinus betulus and Fagus sylvatica established at ca. 6,000 cal bp, coinciding with the first indicators of agricultural activity in the region and a transient climatic shift to cooler and moister conditions. Human impact on the vegetation remained initially very low, only increasing during the Bronze Age, at ca. 3,400 cal bp. Large-scale forest openings and the establishment of the present-day cultural landscape occurred only during the past 500 years. The persistence of highly diverse mixed forest under absent or low anthropogenic disturbance until the Early Middle Ages corroborates the role of human impact in the impoverishment of temperate forests elsewhere in Central Europe. The preservation or reestablishment of such diverse forests may mitigate future climate change impacts, specifically by lowering fire risk under warmer and drier conditions.

Development of the mixed conifer forest in northern New Mexico and its relationship to Holocene environmental change

2008 ◽  
Vol 69 (2) ◽  
pp. 263-275 ◽  
Author(s):  
R. Scott Anderson ◽  
Renata B. Jass ◽  
Jaime L. Toney ◽  
Craig D. Allen ◽  
Luz M. Cisneros-Dozal ◽  
...  
Keyword(s):  
New Mexico ◽  
Pinus Ponderosa ◽  
Late Glacial ◽  
Conifer Forest ◽  
Lake Levels ◽  
Mixed Conifer ◽  
The Holocene ◽  
Groundwater Levels ◽  
Mixed Conifer Forest ◽  
Jemez Mountains

Chihuahueños Bog (2925 m) in the Jemez Mountains of northern New Mexico contains one of the few records of late-glacial and postglacial development of the mixed conifer forest in southwestern North America. The Chihuahueños Bog record extends to over 15,000 cal yr BP. AnArtemisiasteppe, then an openPiceawoodland grew around a small pond until ca. 11,700 cal yr BP whenPinus ponderosabecame established. C/N ratios,δ13C andδ15N values indicate both terrestrial and aquatic organic matter was incorporated into the sediment. Higher percentages of aquatic algae and elevated C/N ratios indicate higher lake levels at the opening of the Holocene, but a wetland developed subsequently as climate warmed. From ca. 8500 to 6400 cal yr BP the pond desiccated in what must have been the driest period of the Holocene there. C/N ratios declined to their lowest Holocene levels, indicating intense decomposition in the sediment. Wetter conditions returned after 6400 cal yr BP, with conversion of the site to a sedge bog as groundwater levels rose. Higher charcoal influx rates after 6400 cal yr BP probably result from greater biomass production rates. Only minor shifts in the overstory species occurred during the Holocene, suggesting that mixed conifer forest dominated throughout the record.

scholarly journals Timing of Medieval Fluvial Aggradation at Bremgarten in the Southern Upper Rhine Graben – a Test for Luminescence Dating

2009 ◽  
Vol 57 (3/4) ◽  
pp. 411-432
Author(s):  
Manfred Frechen ◽  
Dietrich Ellwanger ◽  
Daniel Rimkus ◽  
Astrid Techmer
Keyword(s):  
Little Ice Age ◽  
Radiocarbon Dating ◽  
Experimental Studies ◽  
Luminescence Dating ◽  
Ice Age ◽  
Upper Rhine Graben ◽  
River Rhine ◽  
Fluvial Sediments ◽  
The Holocene ◽  
Short Period

Abstract. The Holocene flood plain of the River Rhine is a complex dynamic sedimentary system. A series of geochronological results for the Bremgarten section including optically stimulated luminescence (OSL) and radiocarbon dating was determined to improve the understanding of part of the Holocene evolution of the River Rhine. The applied single aliquot regenerative (SAR) protocols and the applied experimental studies to find the best luminescence behaviour leave us with confidence that OSL dating is a suitable method for dating fluvial sediments from large river systems. Insufficient bleaching of the sediments from Bremgarten prior to deposition seems to be not as dramatic as previously thought. OSL and radiocarbon dating results give evidence for a short period of major erosion and re-sedimentation of fluvial sediments from the “Tiefgestade” at the Bremgarten section between 500 and 600 years before present. This time period correlates with the beginning of the Little Ice Age at about AD 1450. Several severe floods occurred in Southern Germany between AD 1500 and 1750; all those floods correlate to the period of the Little Ice Age, including the destruction of the village of Neuenburg AD 1525.

CONTRIBUTIONS TO THE HOLOCENE PALEOECOLOGY OF WESTCENTRAL CANADA: A LATE-GLACIAL DEPOSIT FROM THE MISSOURI COTEAU

1964 ◽  
Vol 42 (6) ◽  
pp. 677-692 ◽  
Author(s):  
J. C. Ritchie ◽  
Bernard de Vries
Keyword(s):  
Great Plains ◽  
Late Glacial ◽  
Pollen Spectrum ◽  
Pollen Diagram ◽  
Glacial Deposit ◽  
Carbon 14 ◽  
Missouri Coteau ◽  
Plant Assemblages ◽  
Mixed Prairie ◽  
Artemisia Pollen

A buried deposit of limnic sediment was excavated from a site on the Missouri Coteau of Saskatchewan, within the Mixed Prairie section of the Great Plains. Carbon-14 determinations indicate that the section is late-glacial, possibly deposited during an interstadial terminated by the Condie (= Valders?) re-advance. On the basis of the records of about 60 taxa of Tracheophyta and a pollen diagram, the section is characterized by lower, middle, and upper plant assemblages. It is suggested that the lower and upper assemblages, distinguished mainly by a Picea – Shepherdia canadensis – Salix – Artemisia pollen spectrum, indicate the prevalence on mesic sites of a spruce forest. The middle assemblage, having an array of macrofossils and a few microfossils of temperate geographical affinity and a pollen spectrum suggesting relatively less spruce and (or) more herbaceous vegetation, is interpreted in terms of a mixed spruce–poplar forest on mesic sites with shrub and grassland communities on the more xeric habitats. This tripartite division of the section in terms of ecologically concordant plant assemblages suggests an amelioration of environment followed by a deterioration which was probably correlative with the Condie re-advance.

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