Late-glacial and Holocene vegetation history of the Magellanic rain forest in southwestern Patagonia, Chile

2004 ◽  
Vol 13 (4) ◽  
pp. 249-255 ◽  
Author(s):  
Martinus Fesq-Martin ◽  
Arne Friedmann ◽  
Michael Peters ◽  
Jan Behrmann ◽  
Rolf Kilian
Keyword(s):  
Rain Forest ◽  
Vegetation History ◽  
Late Glacial ◽  
History Of ◽  
Late Glacial And Holocene

scholarly journals Transformation of Lake Ecosystem into Peat Bog and Vegetation History Based on Durne Bagno Mire (Lublin Polesie, E Poland)

2007 ◽  
Vol 29 (-1) ◽  
pp. 23-43 ◽  
Author(s):  
Krystyna Bałaga
Keyword(s):  
Vegetation History ◽  
Chemical Elements ◽  
Late Glacial ◽  
Unique Element ◽  
Peat Bogs ◽  
Lake Ecosystem ◽  
Peat Bog ◽  
Mineral Material ◽  
Late Glacial And Holocene ◽  
Almost All

Transformation of Lake Ecosystem into Peat Bog and Vegetation History Based on Durne Bagno Mire (Lublin Polesie, E Poland)In this paper, the history of Durne Bagno, i.e. the largest peat bog in the Lublin Polesie, is shown. Peat bogs are a unique element of the Polesie landscape. They occur mostly in the subregion of the Łęczna-Włodawa Lake District occupying 1.07% of its area. They fill basin-shaped depressions without outflow, often in the immediate vicinity of dystrophic lakes. Based on interdisciplinary research, the changes of vegetation cover and the Durne Bagno lake-mire ecosystem in the Late Glacial and Holocene are presented. The environmental conditions are reconstructed from pollen analysis, detailed identification of algae ofPediastrumgenus and chemical composition of deposits, together with the results of Cladocera analysis. The distribution of archaeological artefacts in the surroundings of Durne Bagno peat bog gives the view on the intensity of settlement in this area. The duration of the limnic and mire stages during the development of the ecosystem was different in different parts of the examined depression. In its central part the limnic stage lasted about 8000 years and included the period from the Late Glacial to the middle Holocene (to about 6000 BP). It is represented by 7 pollen zones and 6 chemical zones. The mire stage contained a part the Atlantic period and on the Subboreal and Subatlantic periods. It is represented by 4 pollen zones and 5 chemical zones. Limnic and mire deposits differ widely in the concentrations of chemical elements. The contents of mineral material and almost all analyzed elements in limnic deposits are high. These deposits are characterized by positive correlation between the contents of Zn and Cr and the frequency of Cladocera fauna. Peat contains very low amount of mineral material. The contents of Ca, Sr and Ba are rather high in sedgemoss peat. The concentrations of these elements decrease upwards due to oligotrophic processes and sedentation of sedge-Eriophorum-Sphagnumpeat. Peat succession was modified by pastoral economy of prehistoric man.

Late Glacial and Holocene history of Plešné Lake and its surrounding landscape based on pollen and palaeoalgological analyses

Biologia ◽  
2006 ◽  
Vol 61 (20) ◽  
Author(s):  
Vlasta Jankovská
Keyword(s):  
Late Glacial ◽  
Forest Steppe ◽  
Southern Europe ◽  
Pollen Diagram ◽  
History Of ◽  
The Bohemian Forest ◽  
Surrounding Landscape ◽  
Late Glacial And Holocene ◽  
High Degree ◽  
Biostratigraphic Units

AbstractPollen analysis has been carried out on a 549 cm thick sediment profile from lake Plešné jezero (Plešné Lake) in the Bohemian Forest (Šumava, Czech Republic; 1090 m a.s.l.; 48°47′ N; 13°52′ E). Analyses of 67 samples characterise the development of the lake biotope and the surrounding landscape during the last ca. 14,000 years. The pollen diagram shows a very distinct transition between the Late Glacial and the Holocene biostratigraphic units at a depth of ca. 312 cm. In the surroundings of Plešné Lake the vegetation was treeless during the entire Late Glacial. The alpine tree limit, formed by Betula and Pinus with undergrowth of shrubs, might have been at ca. 500 m a.s.l. Pollen transported from long distances was significant due to the openness of the landscape, coming from southern Europe and even Africa, and including high numbers of Artemisia, Poaceae, Chenopodiaceae, and some other herbs and shrubs from steppe and forest-steppe areas in southern Europe or Africa (likely Ephedra, certainly Lygeum spartum). The expansion of shrubs, particularly Juniperus, preceded the expansion of trees near the end of the Late Glacial. Afforestation of the region by thin stands of Betula and Pinus occurred during the Preboreal. Significant warming in the Boreal resulted in the expansion of Corylus, Quercetum mixtum (QM) trees, and probably also Picea and Alnus. Picea as well as QM trees were further expanding during the Early Atlantic. Picea was the dominant tree during the Late Atlantic and Fagus started to spread towards its end. Abrupt expansion of Abies marks the Subboreal. A high degree of afforestation (Abies, Fagus, Picea) was characteristic for the Early Subatlantic. During Late Subatlantic, pollen of synanthropic plants appears. Phases of the lake biotope development were defined on the basis of coccal green algae and Isoëtes.

scholarly journals Some aspects of the last glaciation in the Mazury Lake District (north-eastern Poland)

2013 ◽  
Vol 53 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Katarzyna Pochocka-Szwarc
Keyword(s):  
Ice Sheet ◽  
Late Glacial ◽  
Climatic Changes ◽  
Lake District ◽  
Last Glaciation ◽  
North Eastern ◽  
Melt Water ◽  
History Of ◽  
Organic Sediments ◽  
Late Glacial And Holocene

ABSTRACT The morphology of the Mazury Lake District (north-eastern Poland) dates from 24-19 ka (main stadial of the youngest Vistulian glaciation). During this last glacial maximum (MIS 2) a belt with lacustrine basins was formed when the ice sheet retreated at the end of the Pomeranian phase. The ice-sheet retreat is morphologically also expressed by the occurrence of end moraines. The study area is situated in the Skaliska Basin, in the northern part of the Lake District (near the Polish/ Russian border), at the periphery of zone with end moraines. Originally the basin was an ice-dammed depression filled with melt water; the water flowed out into the developing Pregoła valley when the ice retreated and did no longer dam off the depression. The basin, which is surrounded by hill-shaped moraines, is filled now with Late Glacial and Holocene glaciolacustrine sediments. The organic sediments of the basin record the history of the Late Glacial and Holocene climatic changes in this region.

Late-glacial deposits at Llyn Dwythwch and Nant Ffrancon, Caernarvonshire

1962 ◽  
Vol 244 (716) ◽  
pp. 459-481 ◽  
Keyword(s):  
Vegetation History ◽  
Late Glacial ◽  
Glacial Period ◽  
Late Glacial Period ◽  
Lacustrine Deposits ◽  
Kettle Hole ◽  
Lycopodium Annotinum ◽  
Northern Distribution ◽  
History Of ◽  
Zone Ii

The stratigraphy of sediments in two lake basins in the Caernarvonshire mountains at 600 and 900 ft. O.D. is described and it is shown that the basal layers were deposited in the Late-glacial Period. The deposits of a third site occupying a kettle-hole in morainic gravels at 1223 ft. O.D. are described and here the Late-glacial Period is not represented. The relation of these sites to the youngest corrie moraines of the district indicates that the latter were formed during the post-Allerod climatic regression (Zone III). The vegetation history of the district was studied by means of pollen analysis of lacustrine deposits from the two first-mentioned sites (above). The vegetation of the Late-glacial Period at first formed tundra (Zone I) in which arctic-alpines, notably Betula , flourished together with species of oceanic and oceanic-northern distribution and calcicolous, eutrophic and moderately thermophilous plants. The spread of juniper scrub preceded the arrival of tree birches, which form ‘park-tundra’ in Zone II at Nant Ffrancon but failed to grow as high as Llyn Dwythwch. The birch ‘ parktundra’ is considered to have covered Britain south of the Forth-Clyde at low altitudes and to have occupied central and eastern Ireland at this time. The climatic deterioration of Zone III is clearly registered by the decline of juniper and tree birch and the local severity of conditions is demonstrated by the increased abundance of the chianophilous fern, Cryptogramma crispa, Lycopodium selago, Saussurea alpina and other montane herbs. The extensive occurrence of solifluxion, augmented by glacier streams, brought down silt and clay into the lakes. The ensuing amelioration in climate and the course of forest development through the Post-glacial Period is briefly traced and the persistence of certain elements of the present mountain flora from the Late-glacial Period demonstrated. A description is given of the spores of Cryptogramma crispa which together with Lycopodium annotinum and Saussurea alpina are new to British Late-glacial records.

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