Vegetation and climate change during the Last Interglacial-Glacial cycle in western Tasmania, Australia

2000 ◽  
Vol 155 (1-2) ◽  
pp. 195-209 ◽  
Author(s):  
Eric A. Colhoun
Keyword(s):  
Climate Change ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
Vegetation And Climate

scholarly journals Ecosystem regimes and responses in a coupled ancient lake system from MIS 5b to present: the diatom record of lakes Ohrid and Prespa

2016 ◽  
Vol 13 (10) ◽  
pp. 3147-3162 ◽  
Author(s):  
Aleksandra Cvetkoska ◽  
Elena Jovanovska ◽  
Alexander Francke ◽  
Slavica Tofilovska ◽  
Hendrik Vogel ◽  
...  
Keyword(s):  
Climate Change ◽  
Chemical Properties ◽  
Regime Shifts ◽  
Interglacial Period ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
Lake Ohrid ◽  
Lake Prespa ◽  
Lake System ◽  
Deep Site

Abstract. We reconstruct the aquatic ecosystem interactions since the last interglacial period in the oldest, most diverse, hydrologically connected European lake system, by using palaeolimnological diatom and selected geochemistry data from Lake Ohrid “DEEP site” core and equivalent data from Lake Prespa core, Co1215. Driven by climate forcing, the lakes experienced two adaptive cycles during the last 92 ka: "interglacial and interstadial" and "glacial" cycle. The short-term ecosystems reorganizations, e.g. regime shifts within these cycles substantially differ between the lakes, as evident from the inferred amplitudes of variation. The deeper Lake Ohrid shifted between ultra oligo- and oligotrophic regimes in contrast to the much shallower Lake Prespa, which shifted from a deeper, (oligo-) mesotrophic to a shallower, eutrophic lake and vice versa. Due to the high level of ecosystem stability (e.g. trophic state, lake level), Lake Ohrid appears relatively resistant to external forcing, such as climate and environmental change. Recovering in a relatively short time from major climate change, Lake Prespa is a resilient ecosystem. At the DEEP site, the decoupling between the lakes' response to climate change is marked in the prolonged and gradual changes during the MIS 5/4 and 2/1 transitions. These response differences and the lakes' different physical and chemical properties may limit the influence of Lake Prespa on Lake Ohrid. Regime shifts of Lake Ohrid due to potential hydrological change in Lake Prespa are not evident in the data presented here. Moreover, a complete collapse of the ecosystems functionality and loss of their diatom communities did not happen in either lake for the period presented in the study.

scholarly journals An Orchid in Retrograde: Climate-Driven Range Shift Patterns of Ophrys helenae in Greece

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 470
Author(s):  
Martha Charitonidou ◽  
Konstantinos Kougioumoutzis ◽  
John M. Halley
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Species Distribution Modelling ◽  
Range Shift ◽  
Last Interglacial ◽  
Distribution Modelling ◽  
Species Response ◽  
Northwestern Greece ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Climate change is regarded as one of the most important threats to plants. Already species around the globe are showing considerable latitudinal and altitudinal shifts. Helen’s bee orchid (Ophrys helenae), a Balkan endemic with a distribution center in northwestern Greece, is reported to be expanding east and southwards. Since this southeastern movement goes against the usual expectations, we investigated via Species Distribution Modelling, whether this pattern is consistent with projections based on the species’ response to climate change. We predicted the species’ future distribution based on three different climate models in two climate scenarios. We also explored the species’ potential distribution during the Last Interglacial and the Last Glacial Maximum. O. helenae is projected to shift mainly southeast and experience considerable area changes. The species is expected to become extinct in the core of its current distribution, but to establish a strong presence in the mid- and high-altitude areas of the Central Peloponnese, a region that could have provided shelter in previous climatic extremes.

scholarly journals Excursions to C<sub>4</sub> vegetation recorded in the Upper Pleistocene loess of Surduk (Northern Serbia): an organic isotope geochemistry study

2013 ◽  
Vol 9 (3) ◽  
pp. 1001-1014 ◽  
Author(s):  
C. Hatté ◽  
C. Gauthier ◽  
D.-D. Rousseau ◽  
P. Antoine ◽  
M. Fuchs ◽  
...  
Keyword(s):  
General Pattern ◽  
Free Water ◽  
Circulation Pattern ◽  
Water Evaporation ◽  
C3 Plants ◽  
Mean Annual Precipitation ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
The Balkans ◽  
The Mediterranean

Abstract. Loess sequences have been intensively studied to characterize past glacial climates of the 40–50° north and south latitude zones. Combining different approaches of sedimentology, magnetism, geochemistry, geochronology and malacology allows the general pattern of the climate and environment of the last interglacial–glacial cycle in Eurasia and America to be characterized. Previous studies performed in Europe have highlighted the predominance (if not the sole occurrence) of C3 vegetation. The presence of C3 plants suggests a regular distribution of precipitation along the year. Therefore, even if the mean annual precipitation remained very low during the most extensive glacial times, free water was available for more than 2 months per year. Contrarily, the δ13C record of Surduk (Serbia) clearly shows the occurrence and dominance of C4 plants during at least 4 episodes of the last glacial times at 28.0–26.0 kyr cal BP, 31.4–30.0 kyr cal BP, 53.4–44.5 kyr cal BP and 86.8–66.1 kyr. The C4 plant development is interpreted as a specific atmospheric circulation pattern that induces short and dry summer conditions. As possible explanation, we propose that during "C4 episodes", the Mediterranean Sea would have been under the combined influence of the following: (i) a strong meridional circulation unfavorable to water evaporation that reduced the Mediterranean precipitation on the Balkans; and (ii) a high positive North Atlantic Western Russian (NA/WR)-like atmospheric pattern that favored northerlies over westerlies and reduced Atlantic precipitation over the Balkans. This configuration would imply very dry summers that did not allow C3 plants to grow, thus supporting C4 development. The intra-"C4 episode" periods would have occurred under less drastic oceanic and atmospheric patterns that made the influence of westerlies on the Balkans possible.

Palynology of the Last Interglacial-Glacial Cycle in Midlatitudes of Southern Chile

1981 ◽  
Vol 16 (3) ◽  
pp. 293-321 ◽  
Author(s):  
Calvin J. Heusser
Keyword(s):  
Primary Component ◽  
Southern Chile ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
The Holocene ◽  
Westerly Winds ◽  
Pollen And Spores ◽  
Components Analysis ◽  
Age Relations ◽  
Nothofagus Dombeyi

AbstractPollen and spores in stratigraphic sections located between 40 and 42°S range in age from the Holocene, through much of the Llanquihue Glaciation, to the last interglaciation. Chronology of the stratigraphy derives from some 35 14C ages and the age relations of Llanquihue Drift and related deposits. Q-Mode, rotated, principal-components analysis of four key pollen records covering the last interglacial-glacial cycle resulted in four leading components: Nothofagus dombeyi type, Gramineae, Weinmannia-Fitzroya type, and Myrtaceae. Analysis emphasizes interaction between the first two components. Loadings of Gramineae during the interglaciation are high, unlike the Holocene; Weinmannia-Fitzroya-type loadings, prominent in the Holocene, are negligible during the interglaciation. N. dombeyi type is the primary component during Llanquihue Glaciation; it becomes modified by increases of Gramineae sometime after 31,000 and before 14,000 yr B.P. and of Myrtaceae later. The Myrtaceae with Weinmannia-Fitzroya type also registers some activity around 42,000 yr B.P. Fluctuations in the belt of westerly winds, reflecting changing meteorological conditions in polar latitudes, are suggested by these data. With the belt located farther south than it is today, interglacial climate was much drier and warmer than during the Holocene; more northerly displacement of the belt obtained when climate was colder during Llanquihue Glaciation. Evidence from comparable latitudes in the Southern Hemisphere points toward a synchrony of major climatic events indicating harmonious fluctuations in the position of the westerlies.

Correlation and interpretation of paleosols and loess across European Russia and Asia over the last interglacial–glacial cycle

2003 ◽  
Vol 60 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Nathaniel W. Rutter ◽  
Dean Rokosh ◽  
Michael E. Evans ◽  
Edward C. Little ◽  
Jiri Chlachula ◽  
...  
Keyword(s):  
Loess Plateau ◽  
European Russia ◽  
Chinese Loess Plateau ◽  
Russian Plain ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
Central Siberia ◽  
Chinese Loess ◽  
Loess Deposition ◽  
The Chinese Loess Plateau

AbstractLoess-paleosol sequences of the last interglacial-glacial cycle are correlated from European Russia to central Siberia and the Chinese Loess Plateau. During cold periods represented by marine oxygen isotope stages (OIS) 2 and 4, loess deposition dominated in the Russian Plain and the Loess Plateau. In central Siberia, loess deposition took place also, but five to seven thin, weakly developed paleosols are identified in both stages. OIS 3, in the Chinese Loess Plateau near Yangchang, consists of a loess bed that is flanked by two weakly developed paleosols. At Kurtak, Siberia, OIS 3 is represented by two distinct, stacked paleosols with no loess bed separating the paleosols. In the Russian Plain, OIS 3 consists of a single, possibly welded paleosol, representing upper and lower stage-3 climates. Brunisols and Chernozems dominate the profiles in China and Siberia, whereas Regosols, Luvisols, and Chernozems are evident in the northern and southern Russian Plain, respectively. OIS 5 is represented in China and the Russian Plain by pedo complexes in a series of welded soils, whereas in contrast, the Kurtak site consists of six paleosols with interbedded loess. The paleosols consist largely of Brunisols and Chernozems. Although the three areas examined have different climates, geographical settings, and loess source areas, they all had similar climate changes during the last interglacial-glacial cycle.

Vegetation and climate change in the Pro-Namib and Namib Desert based on repeat photography: Insights into climate trends

2019 ◽  
Vol 165 ◽  
pp. 119-131 ◽  
Author(s):  
Richard F. Rohde ◽  
M. Timm Hoffman ◽  
Ian Durbach ◽  
Zander Venter ◽  
Sam Jack
Keyword(s):  
Climate Change ◽  
Repeat Photography ◽  
Climate Trends ◽  
Namib Desert ◽  
Vegetation And Climate

scholarly journals Towards assessing the influence of sediment loading on Last Interglacial sea level

2019 ◽  
Vol 220 (1) ◽  
pp. 384-392
Author(s):  
T Pico
Keyword(s):  
Sea Level ◽  
Tectonic Uplift ◽  
Sediment Loading ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
Isostatic Adjustment ◽  
Uplift Rates ◽  
History Of ◽  
The Impact ◽  
The Last Glacial

SUMMARY Locally, the elevation of last interglacial (LIG; ∼122 ka) sea level markers is modulated by processes of vertical displacement, such as tectonic uplift or glacial isostatic adjustment, and these processes must be accounted for in deriving estimates of global ice volumes from geological sea level records. The impact of sediment loading on LIG sea level markers is generally not accounted for in these corrections, as it is assumed that the impact is negligible except in extremely high depositional settings, such as the world's largest river deltas. Here we perform a generalized test to assess the extent to which sediment loading may impact global variability in the present-day elevation of LIG sea level markers. We numerically simulate river sediment deposition using a diffusive model that incorporates a migrating shoreline to construct a global history of sedimentation over the last glacial cycle. We then calculate sea level changes due to this sediment loading using a gravitationally self-consistent model of glacial isostatic adjustment, and compare these predictions to a global compilation of LIG sea level data. We perform a statistical analysis, which accounts for spatial autocorrelation, across a global compilation of 1287 LIG sea level markers. Though limited by uncertainties in the LIG sea level database and the precise history of river deposition, this analysis suggests there is not a statistically significant global signal of sediment loading in LIG sea level markers. Nevertheless, at sites where LIG sea level markers have been measured, local sea level predicted using our simulated sediment loading history is perturbed up to 16 m. More generally, these predictions establish the relative sensitivity of different regions to sediment loading. Finally, we consider the implications of our results for estimates of tectonic uplift rates derived from LIG marine terraces; we predict that sediment loading causes 5–10 m of subsidence over the last glacial cycle at specific locations along active margin regions such as California and Barbados, where deriving long-term tectonic uplift rates from LIG shorelines is a common practice.

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