scholarly journals Early Last Interglacial environmental changes recorded by speleothems from Katerloch (south‐east Austria)

Author(s):  
Charlotte Honiat ◽  
Daniela Festi ◽  
Paul S. Wilcox ◽  
R. Lawrence Edwards ◽  
Hai Cheng ◽  
...  
Author(s):  
Eleonora Regattieri ◽  
Biagio Giaccio ◽  
Sebastien Nomade ◽  
Alexander Francke ◽  
Hendrik Vogel ◽  
...  

2018 ◽  
Author(s):  
Tristan Salles ◽  
Jodie Pall ◽  
M. Jody Webster ◽  
Belinda Dechnik

Abstract. Assemblages of corals characterise specific reef biozones and the environmental conditions that change laterally across a reef and with depth. Drill cores through fossil reefs record the time- and depth-distribution of assemblages, which captures a partial history of the vertical growth response of reefs to changing palaeoenvironmental conditions. The effects of environmental factors on reef growth are well understood on ecological time-scales but are poorly constrained at centennial to millennial timescales. pyReef-Core is a stratigraphic forward model designed to solve the inverse problem of unobservable environmental processes controlling vertical reef development by simulating the physical, biological and sedimentological processes that determine vertical assemblage changes in drill cores. It models the stratigraphic development of coral reefs at centennial to millennial timescales under environmental forcing conditions including accommodation (relative sea level upward growth), oceanic variability (flow speed, nutrients, pH and temperature), sediment input and tectonics. It also simulates competitive coral assemblage interactions using the generalised Lotka-Volterra system of equations (GLVEs) and can be used to infer the influence of environmental conditions on the zonation and vertical accretion and stratigraphic succession of coral assemblages over decadal timescales and greater. The tool can quantitatively test carbonate platform development under the influence of ecological and environmental processes, and efficiently interpret vertical growth and karstification patterns observed in drill cores. We provide two realistic case studies illustrating the basic capabilities of the model and use it to reconstruct (1) the Holocene history (from 8500 years to present) of coral community responses to environmental changes, and (2) the evolution of an idealised coral-reef core since the Last Interglacial (from 140 000 years to present) under the influence of sea-level change, subsidence and karstification. We find that the model reproduces the details of the formation of existing coral-reef stratigraphic sequences both in terms of assemblages succession, accretion rates and depositional thicknesses. It can be applied to estimate the impact of changing environmental conditions on growth rates and patterns under many different settings and initial conditions.


Quaternary ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 9 ◽  
Author(s):  
Anastasia Markova ◽  
Andrey Puzachenko

Small mammal remains obtained from the European localities dated to the Eemian (Mikulino) age have been analyzed for the first time at a regional scale based on the present biogeographical regionalization of Europe. The regional faunas dated to the warm interval in the first part of the Late Pleistocene display notable differences in fauna composition, species richness, and diversity indices. The classification of regional faunal assemblages revealed distinctive features of small mammal faunas in Eastern and Western Europe during the Eemian (=Mikulino, =Ipswichian) Interglacial. Faunas of the Iberian Peninsula, Apennine Peninsula, and Sardinia Island appear to deviate from the other regions. In the Eemian Interglacial, the maximum species richness of small mammals (≥40 species) with a relatively high proportion of typical forest species was recorded in Western and Central Europe and in the western part of Eastern Europe. The lowest species richness (5–14 species) was typical of island faunas and of those in the north of Eastern Europe. The data obtained make it possible to reconstruct the distribution of forest biotopes and open habitats (forest-steppe and steppe) in various regions of Europe. Noteworthy is a limited area of forests in the south and in the northeastern part of Europe. In these regions, it seems likely that under conditions of relatively high temperatures characteristic of the Last Interglacial and an insufficient moisture supply there could exist open forest stands or forest-steppe landscapes, as suggested by the presence of species indicative of forest-steppe and steppe north of the forest zone. The results obtained are useful in modeling changes in the mammal faunas as well as environmental changes in entire Europe due to global climatic changes (including the global warming recorded at present).


2018 ◽  
Vol 11 (6) ◽  
pp. 2093-2110 ◽  
Author(s):  
Tristan Salles ◽  
Jodie Pall ◽  
Jody M. Webster ◽  
Belinda Dechnik

Abstract. Assemblages of corals characterise specific reef biozones and the environmental conditions that change spatially across a reef and with depth. Drill cores through fossil reefs record the time and depth distribution of assemblages, which captures a partial history of the vertical growth response of reefs to changing palaeoenvironmental conditions. The effects of environmental factors on reef growth are well understood on ecological timescales but are poorly constrained at centennial to geological timescales. pyReef-Core is a stratigraphic forward model designed to solve the problem of unobservable environmental processes controlling vertical reef development by simulating the physical, biological and sedimentological processes that determine vertical assemblage changes in drill cores. It models the stratigraphic development of coral reefs at centennial to millennial timescales under environmental forcing conditions including accommodation (relative sea-level upward growth), oceanic variability (flow speed, nutrients, pH and temperature), sediment input and tectonics. It also simulates competitive coral assemblage interactions using the generalised Lotka–Volterra system of equations (GLVEs) and can be used to infer the influence of environmental conditions on the zonation and vertical accretion and stratigraphic succession of coral assemblages over decadal timescales and greater. The tool can quantitatively test carbonate platform development under the influence of ecological and environmental processes and efficiently interpret vertical growth and karstification patterns observed in drill cores. We provide two realistic case studies illustrating the basic capabilities of the model and use it to reconstruct (1) the Holocene history (from 8500 years to present) of coral community responses to environmental changes and (2) the evolution of an idealised coral reef core since the last interglacial (from 140 000 years to present) under the influence of sea-level change, subsidence and karstification. We find that the model reproduces the details of the formation of existing coral reef stratigraphic sequences both in terms of assemblages succession, accretion rates and depositional thicknesses. It can be applied to estimate the impact of changing environmental conditions on growth rates and patterns under many different settings and initial conditions.


2013 ◽  
Vol 9 (6) ◽  
pp. 2525-2547 ◽  
Author(s):  
J. Jouzel

Abstract. For about 50 yr, ice cores have provided a wealth of information about past climatic and environmental changes. Ice cores from Greenland, Antarctica and other glacier-covered regions now encompass a variety of time scales. However, the longer time scales (e.g. at least back to the Last Glacial period) are covered by deep ice cores, the number of which is still very limited: seven from Greenland, with only one providing an undisturbed record of a part of the last interglacial period, and a dozen from Antarctica, with the longest record covering the last 800 000 yr. This article aims to summarize this successful adventure initiated by a few pioneers and their teams and to review key scientific results by focusing on climate (in particular water isotopes) and climate-related (e.g. greenhouse gases) reconstructions. Future research is well taken into account by the four projects defined by IPICS. However, it remains a challenge to get an intact record of the Last Interglacial in Greenland and to extend the Antarctic record through the mid-Pleistocene transition, if possible back to 1.5 Ma.


2014 ◽  
Vol 82 (3) ◽  
pp. 553-566 ◽  
Author(s):  
Laura E. Strickland ◽  
Richard G. Baker ◽  
Robert S. Thompson ◽  
Dane M. Miller

AbstractNinety plant macrofossil taxa from the Ziegler Reservoir fossil site near Snowmass Village, Colorado, record environmental changes at high elevation (2705 m asl) in the Rocky Mountains during the Last Interglacial Period. Present-day vegetation is aspen forest (Populus tremuloides) intermixed with species of higher (Picea,Abies) and lower (Artemisia,Quercus) elevations. Stratigraphic units 4–13 contain montane forest taxa found near the site today and several species that today generally live at lower elevations within (Abies concolor,Lycopus americanus) and outside Colorado (Najas flexilis). These data suggest near-modern climatic conditions, with slightly warmer summer and winter temperatures. This montane forest period was succeeded by a shorter treeless interval (Unit 14) representing colder and/or drier conditions. In units 15–16, conifer trees reoccur but deciduous and herb taxa are lacking, suggesting a return to warmer conditions, although cooler than during the earlier forest period. Comparison of these inferred paleoclimatic changes with the site's geochronologic framework indicates that the lower interval of sustained warmth correlates with late MIS 6–early 5b (~138–94 ka), the cold interval with MIS 5b (~94–87 ka), and the uppermost cool assemblages with MIS 5a (~87–77 ka).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Chiocchio ◽  
Jan. W. Arntzen ◽  
Iñigo Martínez-Solano ◽  
Wouter de Vries ◽  
Roberta Bisconti ◽  
...  

AbstractGenetic diversity feeds the evolutionary process and allows populations to adapt to environmental changes. However, we still lack a thorough understanding of why hotspots of genetic diversity are so 'hot'. Here, we analysed the relative contribution of bioclimatic stability and genetic admixture between divergent lineages in shaping spatial patterns of genetic diversity in the common toad Bufo bufo along the Italian peninsula. We combined population genetic, phylogeographic and species distribution modelling (SDM) approaches to map ancestral areas, glacial refugia, and secondary contact zones. We consistently identified three phylogeographic lineages, distributed in northern, central and southern Italy. These lineages expanded from their ancestral areas and established secondary contact zones, before the last interglacial. SDM identified widespread glacial refugia in peninsular Italy, sometimes located under the present-day sea-level. Generalized linear models indicated genetic admixture as the only significant predictor of the levels of population genetic diversity. Our results show that glacial refugia contributed to preserving both levels and patterns of genetic diversity across glacial-interglacial cycles, but not to their formation, and highlight a general principle emerging in Mediterranean species: higher levels of genetic diversity mark populations with substantial contributions from multiple genetic lineages, irrespective of the location of glacial refugia.


2019 ◽  
Vol 28 (2) ◽  
pp. 262-274
Author(s):  
N. P. Gerasimenko ◽  
І. P. Koval’chuk

The aim of this paper is to reveal connections between Upper Pleistocene soil types and the vegetation, which existed during their formation. Palaeovegetation was reconstructed on the basis of pollen analysis, whereas morphological description of palaeosols and the data from their laboratory study (grain-size and bulk chemical analyses, contents of Corg., CaCO3 and dry salts) were used to reconstruct palaeopedological processes. The Kryva Luka sedimentary sequence was accumulated in a deep palaeogully (the incision of which occurred in early Kaydaky times), where, as a result of high sedimentation rates, welldeveloped Upper Pleistocene pedocomplexes formed, on one hand, and very good preservation of pollen was thus guaranteed. Several phases of soil development occurred in Kaydaky, Pryluky and Vytachiv times (the Ukrainian Quaternary framework), all represented in the section by individual palaeosols, separated by loess-like beds, or by erosional surfaces. The data collected demonstrates a cyclic pattern of short-period palaeoenvironmental changes during the Late Pleistocene. The last interglacial is related by paleopedological and pollen data to the Kaydaky unit. The pre-temperate stage of the interglacial is revealed in the gully deposits of subunit ‘kd1a’. The early-temperate stage corresponds to the Luvisol of subunit ‘kd1b’, which was formed under broad-leaved woods dominated by oak. The late-temperate stage is recorded in the Greyzemic Phaeozem of the soil ‘kd3b1’ (by the appearance of hornbeam) and the Mollisol ‘kd3b2’. The post-temperate stage of the interglacial and the transition to the early glacial occurred during formation of the uppermost bed of thelatter and the incipient soil ‘kd3c’. (pedosediments were also accumulated at this time). Both vegetational composition and the soil types reflect a warmer and wetter climate for the temperate part of the last interglacial, as compared to that existing in modern times. The soils of different phases of Pryluky and Vytachiv times were formed during interstadials, with cooler climates than at present. As recorded both in soil types and pollen assemblages, the climates during the early interstadials of Pryluky and Vytachiv times were wetter than now (particularly during the ‘pl1b1’ phase), but during their late interstadials, the climate was drier than the modern one (particularly during the phase ‘pl3b2’). On the basis of TL-dating obtained in sections in western Donetsk area and Central Ukraine, Pryluky times correspond to interstadials and stadials of the early glacial, whereas Vytachiv unit may be related to the middle pleniglacial. Types of cryostructures, connected with loess-like deposits of the stadials, indicate that the studied area in those times was under a severe continental climate, with deep seasonal freezing of the grounds. Nevertheless, the absence of ice pseudomorphs and of pollen of arctoalpine plants indicates that permafrost was not present. Changes in palaeopedogenic processes (as well as in types of sedimentation) mainly paralleled changes observed in the palaeovegetation. The extent of wooded areas, the role of broad-leaved trees in the forest composition, and the spread of xeric herbal associations had particularly notable effects on the development of pedogenic processes.


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