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001-es BibID:	BIBFORM079443
Első szerző:	Buczkó Krisztina (biológus)
Cím:	Diatom-based evidence for abrupt climate changes during the Late Glacial in the Southern Carpathian Mountains / Buczkó Krisztina, Magyari Enikő K., Soróczki-Pintér Éva, Hubay Katalin, Braun Mihály, Bálint Miklós
Dátum:	2009
ISSN:	1788-2281 1789-3348
Megjegyzések:	A high-resolution paleolimnological record from Lake Brazi (TDB-1; 45?23'47"N, 22-54'06"E, 1740 m a.s.l.), a small, glacial lake in the Retezat (South Carpathian Mountains, Romania) provides a sensitive record of the impacts of late glacial climatic change on siliceous algal assemblages. The sequence, ranging from 15,700 cal yr BP to 9500 cal yr BP, suggests that the most significant changes in diatom assemblages took place at 12,800 and 10,400 cal yr BP, when alkaliphilous fragilarioid taxa were replaced by acidophilous diatoms. Altogether eight zones were distinguished with sharp and rapid changes of diatom assemblages. The paper discusses the application of siliceous algae in multi-proxy paleolimnological analyses, demonstrates the advantages and disadvantages of this proxy and presents the story of floristic discovery of unique diatom assemblages, the closest recent analogs of which are found in the arctic region.
Tárgyszavak:	Természettudományok Környezettudományok idegen nyelvű folyóiratközlemény hazai lapban diatoms glacial lakes
Megjelenés:	Central European Geology. - 52 : 3-4 (2009), p. 249-268. -
További szerzők:	Magyari Enikő (1973-) (biológus) Soróczki-Pintér Éva Hubay Katalin (1985-) (biológus, környezetkutató) Braun Mihály (1966-) (vegyész, analitikus) Bálint Miklós
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001-es BibID:	BIBFORM073714
Első szerző:	Hubay Katalin (biológus, környezetkutató)
Cím:	Holocene environmental changes as recorded in the geochemistry of glacial lake sediments from Retezat Mountains, South Carpathians / Hubay Katalin, Braun Mihály, Buczkó Krisztina, Pál Ilona, Veres Daniel, Túri Marianna, Biró Tamás, Magyari Enikő
Dátum:	2018
ISSN:	1040-6182
Megjegyzések:	Sediment cores obtained from two deep (>15?m) glacial lakes were analyzed in context of terrestrial vegetation development and in-lake processes from the Retezat Mountains (Southern Carpathians, Romania). Only the Holocene parts were chosen for study for testing what is the connection between geochemical changes and biotas around and in the lakes. The lakes are situated at slightly different altitudes on the northern (Lake Gales, 1990 m a.s.l.) and southern slope (Lake Bucura, 2040 m a.s.l.), respectively. Changes in geochemical composition were relatively low amplitude during the studied period (10,300?1790 and 10,300?695?cal?yr BP) in both lakes, but the applicability of enrichment factor (EF) for geochemical elements and diatom ecological traits (guilds) in paleoecological reconstruction were demonstrated in this paper. The main changes have been observed at ca. 10,670?9000, 6500 and 3100?cal?yr BP in geochemistry, vegetation and siliceous algal assemblages. Catchment soil stabilization was apparent from ?9000?cal?yr BP onwards, in-lake and terrestrial productivity was the highest between 9000 and 6500?cal?yr BP and human impact became the dominant driver in both terrestrial vegetation and sediment geochemical changes and in-lake processes over the last ?3400 years in both lakes. The geochemical record displayed frequent erosional events within the Holocene. The strongest soil erosions clustered around 6500?7400 and 3200-900?cal?yr BP.
Tárgyszavak:	Természettudományok Környezettudományok idegen nyelvű folyóiratközlemény külföldi lapban holocén környezetváltozás geokémia szediment
Megjelenés:	Quaternary International. - 477 (2018), p. 19-39. -
További szerzők:	Braun Mihály (1966-) (vegyész, analitikus) Buczkó Krisztina (1962-) (biológus) Pál Ilona Veres Dániel Túri Marianna (1988-) (geográfus-geoinformatikus) Biró Tamás Magyari Enikő (1973-) (biológus)
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001-es BibID:	BIBFORM079444
Első szerző:	Magyari Enikő (biológus)
Cím:	Radiocarbon chronology of glacial lake sediments in the Retezat Mts (South Carpathians, Romania): a window to Late Glacial and Holocene climatic and paleoenvironmental changes / Magyari Enikő K., Braun Mihály, Buczkó Krisztina, Kern Zoltán, László Péter, Hubay Katalin, Bálint Miklós
Dátum:	2009
ISSN:	1788-2281 1789-3348
Megjegyzések:	As a first piece in a series of Late Quaternary paleoecological studies on the glacial lake sediments of the Retezat Mountains, this study discusses radiocarbon chronology and sediment accumulation rate changes in two sediment profiles in relation to lithostratigraphy, organic content, biogenic silica and major pollenstratigraphic changes. A total of 25 radiocarbon dates were obtained from sediments of two lakes, Lake Brazi (TDB-1; 1740 m a.s.l.) and Lake Gales (Gales-3; 1990 m a.s.l.). Age-depth modeling was performed on TDB-1 using calibrated age ranges from BCal and various curve-fitting methods in psimpoll. Our results suggest that sediment accumulation began between 15,124?15,755 cal yr BP in both lakes and was continuous throughout the Late Glacial and Holocene. We demonstrated that local ecosystem productivity showed delayed response to Late Glacial and Early Holocene climatic changes in the subalpine and alpine zones most likely attributable to the cooling effect of remnant glaciers and meltwater input. However, regional vegetation response was without time lag and indicated forestation and warming at 14,450 and 11,550 cal yr BP, and cooling at ca. 12,800 cal yr BP. In the Holocene one major shift was detected, starting around 6300 cal yr BP and culminating around 5200 cal yr BP. The various proxies suggested summer cooling, shorter duration of the winter ice-cover season and/or increasing size of the water body, probably in response to increasing available moisture.
Tárgyszavak:	Természettudományok Környezettudományok idegen nyelvű folyóiratközlemény hazai lapban folyóiratcikk Late Glacial radiocarbon dating loss-on-ignition pollen glacial lake sediments rapid climate change
Megjelenés:	Central European Geology. - 52 : 3-4 (2009), p. 225-248. -
További szerzők:	Braun Mihály (1966-) (vegyész, analitikus) Buczkó Krisztina (1962-) (biológus) Kern Zoltán László Péter Hubay Katalin (1985-) (biológus, környezetkutató) Bálint Miklós
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001-es BibID:	BIBFORM079876
Első szerző:	Tóth Mónika
Cím:	Limnological changes in South Carpathian glacier-formed lakes (Retezat Mountains, Romania) during the Late Glacial and the Holocene: A synthesis / Mónika Tóth, Krisztina Buczkó, András Specziár, Oliver Heiri, Mihály Braun, Katalin Hubay, Dániel Czakó, Enikő K. Magyari
Dátum:	2018
ISSN:	1040-6182
Megjegyzések:	Remains of aquatic biota preserved in mountain lake sediments provide an excellent tool to study lake ecosystem responses to past climate change. In the PROLONG project a multi-proxy study was performed on sediments of glacier-formed lakes from the Retezat Mountains, Southern Carpathians (Romania). The studied lakes (Lake Brazi and Gales) are situated on the northern slope of the mountain at different altitudes (1740 m and 1990 m a.s.l.). Our main objectives were 1) to describe the main limnological changes in these lakes during the last ca. 15,000 years and 2) to summarize the environmental history of the studied lakes based on taxonomical and functional patterns of the biological proxies. For this synthesis we used the results of diatom and chironomid analyses, and indirect biotic and abiotic parameters, including sediment organic matter (LOI) content, geochemical element concentrations (Al, Ca, S, Sr) and biogenic silica content. Using multivariate numerical approaches we analysed changes in the assemblage structure of siliceous algae and chironomids, compared temporal patterns among proxies, examined the relationship between potential driving factors, chironomid and diatom assemblage changes and identified paleolimnological phases of the lake successions. Changes in assemblage composition and aquatic ecosystem state apparently followed summer insolation, local climatic conditions and local productivity changes driven by these. Diatom and chironomid assemblages generally changed in a similar direction and at a similar time within a lake, but differed to some extent between Lake Brazi and Gales. At both lakes the strongest variations were observed in the Late Glacial and the first half of the Holocene. The strongest Holocene assemblage changes took place in the earliest Holocene in Lake Brazi, but extended into the mid-Holocene in Lake Gales, following long-term insolation changes and climatic changes. In addition, three common zone boundaries were identified: at ca. 14,200 and at ca. 6500 cal yr BP for every records and at ca. 3100 cal yr BP for diatom records in both of the lakes and for the chironomid record of Lake Brazi. This multi-proxy synthesis provides comprehensive data that increase our understanding of the past variability of lake ecosystem functioning and biodiversity in East-Central Europe.
Tárgyszavak:	Természettudományok Környezettudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Quaternary International. - 477 (2018), p. 138-152. -
További szerzők:	Buczkó Krisztina (1962-) (biológus) Specziár András Heiri, Oliver Braun Mihály (1966-) (vegyész, analitikus) Hubay Katalin (1985-) (biológus, környezetkutató) Czakó Dániel Magyari Enikő (1973-) (biológus)
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