scholarly journals The last 7 millennia of vegetation and climate changes at Lago di Pergusa (central Sicily, Italy)

2013 ◽  
Vol 9 (2) ◽  
pp. 2059-2094 ◽  
Author(s):  
L. Sadori ◽  
E. Ortu ◽  
O. Peyron ◽  
G. Zanchetta ◽  
B. Vannière ◽  
...  
Keyword(s):  
Climate Changes ◽  
Global Climate ◽  
Tephra Layer ◽  
Recent Past ◽  
Climate Oscillations ◽  
Climate Fluctuations ◽  
Local Responses ◽  
Vegetation And Climate ◽  
Privileged Site ◽  
Evolution Of Vegetation

Abstract. The aim of this study is to investigate climate changes and human activities under the lens of palynology. Based on a new high-resolution pollen sequence (PG2) from Lago di Pergusa (667 m a.s.l., central Sicily, Italy) covering the last 6700 yr, we propose a reconstruction of climate and landscape changes over the recent past in central Sicily. Compared to former studies from Lago di Pergusa (Sadori and Narcisi, 2001), this work provides a reconstruction of the evolution of vegetation and climate over the last millennia in central Sicily, indeed completing previous results with new data which is particularly detailed on the last 3000 yr. Joint actions of increasing dryness, climate oscillations, and human impact shaped the landscape of this privileged site. Lago di Pergusa, in fact, besides being the main inland lake of Sicily, is very sensitive to climate change and its territory was inhabited and exploited continuously since the prehistory. The lake sediments turned out to be a good observatory for the natural phenomena occurred in the last thousands of years. Results of the pollen-based study are integrated with changes in magnetic susceptibility and a tephra layer characterization. The tephra layer was shown to be related to the Sicanians' event, radiocarbon dated at 3055 ± 75 yr BP (Sadori and Narcisi, 2001). We performed palaeoclimate reconstructions by MAT and WA-PLS. Palaeoclimate reconstructions based on the core show important climate fluctuations throughout the Holocene. Climate reconstruction points out four phases of cooling and enhanced wetness in the last three millennia (2600–2000, 1650–1100, 850–550, 400–200 cal BP). This appears to be the evidence of local responses to global climate oscillations during the recent past.

scholarly journals The last 7 millennia of vegetation and climate changes at Lago di Pergusa (central Sicily, Italy)

2013 ◽  
Vol 9 (4) ◽  
pp. 1969-1984 ◽  
Author(s):  
L. Sadori ◽  
E. Ortu ◽  
O. Peyron ◽  
G. Zanchetta ◽  
B. Vannière ◽  
...  
Keyword(s):  
Climate Changes ◽  
Global Climate ◽  
Weighted Average ◽  
Partial Least Square ◽  
Least Square ◽  
Tephra Layer ◽  
Recent Past ◽  
Climate Oscillations ◽  
Climate Fluctuations ◽  
Vegetation And Climate

Abstract. The aim of this study is to investigate climate changes and human activities under the lens of palynology. Based on a new high-resolution pollen sequence (PG2) from Lago di Pergusa (667 m a.s.l., central Sicily, Italy) covering the last 6700 yr, we propose a reconstruction of climate and landscape changes over the recent past in central Sicily. Compared to former studies from Lago di Pergusa (Sadori and Narcisi, 2001), this work provides a reconstruction of the evolution of vegetation and climate over the last millennia in central Sicily, indeed completing previous results with new pollen data, which is particularly detailed on the last 3000 yr. Joint actions of increasing dryness, climate oscillations, and human impact shaped the landscape of this privileged site. Lago di Pergusa, besides being the main inland lake of Sicily, is very sensitive to climate change and its territory was inhabited and exploited continuously since the Palaeolithic. The lake sediments turned out to be a good observatory for natural phenomena that occurred in the last thousands of years. Results of the pollen-based study are integrated with changes in magnetic susceptibility and a tephra layer characterization. The tephra layer was shown to be related to the Sicanians' event, radiocarbon dated at 3055 ± 75 yr BP (Sadori and Narcisi, 2001). We performed palaeoclimate reconstructions by MAT (Modern Analogues Technique) and WAPLS (Weighted Average Partial Least Square). Palaeoclimate reconstructions based on the core show important climate fluctuations throughout the Holocene. Climate reconstruction points out four phases of cooling and enhanced wetness in the last three millennia (2600–2000, 1650–1100, 850–550, 400–200 cal BP, corresponding to the periods between 650–50 BC, and 300–850, 1100–1400, 1550–1750 AD, respectively). This appears to be the evidence of local responses to global climate oscillations during the recent past.

scholarly journals Environmental and climate changes reflected in the Domuraty 2 section (NE Poland) based on analysis of plant macroremains

2015 ◽  
Vol 55 (2) ◽  
pp. 213-232 ◽  
Author(s):  
Renata Stachowicz-Rybka
Keyword(s):  
Climate Changes ◽  
Global Climate ◽  
High Similarity ◽  
Full Spectrum ◽  
Plant Macroremains ◽  
Thermal Requirements ◽  
Ne Poland ◽  
Carex Rostrata ◽  
Glacial Periods ◽  
Vegetation And Climate

Abstract Research in the Domuraty 2 section was focused on a series of lacustrine-river-swamp deposits in which the full spectrum of vegetation and climate changes was recognised in a detailed analysis of plant macroremains and a comparison with the results of pollen analysis. Based on plant macrofossil data, two (Dom II, Dom III) of three palynologically documented warm units were distinguished in the Domuraty succession. The palaeobotanical data from the Domuraty succession document several successive local vegetation changes in both interglacial and glacial periods, which can be related to global climate oscillations. The succession of local vegetation stands and changes in the vegetation, climate, water level, and trophy during the period of the Domuraty succession were analysed and compared with corresponding parameters of the Augustovian and Ferdynandovian interglacials. The taxonomically most diverse unit is Warm unit Dom II, with the highest share of taxa with high thermal requirements, which was compared to the older Augustovian (A II) and younger Ferdynandovian (F II) units. The comparison of the Domuratovian interglacial flora to that of the Korchevian interglacial in Belarus shows high similarity; most of the extinct taxa or taxa unknown in the present-day flora are common to the Korchevian and Domuratovian floras, suggesting similar age for these two communities. However, the Domuratovian flora lacks a few species important to the Korchevian flora, such as Stratiotes goretskyi, Carex rostrata-pliocenica, Brasenia sp., Caulinia antiqua, Aldrovanda borysthenica, and A. zusii.

Antarctic Climate History and Global Climate Changes

2017 ◽  
Author(s):  
Pontus Lurcock ◽  
Fabio Florindo
Keyword(s):  
Ocean Circulation ◽  
Climate Changes ◽  
Numerical Models ◽  
Global Climate ◽  
Sediment Cores ◽  
Ice Sheets ◽  
Global Ocean ◽  
Climate History ◽  
Global Climate Changes ◽  
Planetary Albedo

Antarctic climate changes have been reconstructed from ice and sediment cores and numerical models (which also predict future changes). Major ice sheets first appeared 34 million years ago (Ma) and fluctuated throughout the Oligocene, with an overall cooling trend. Ice volume more than doubled at the Oligocene-Miocene boundary. Fluctuating Miocene temperatures peaked at 17–14 Ma, followed by dramatic cooling. Cooling continued through the Pliocene and Pleistocene, with another major glacial expansion at 3–2 Ma. Several interacting drivers control Antarctic climate. On timescales of 10,000–100,000 years, insolation varies with orbital cycles, causing periodic climate variations. Opening of Southern Ocean gateways produced a circumpolar current that thermally isolated Antarctica. Declining atmospheric CO2 triggered Cenozoic glaciation. Antarctic glaciations affect global climate by lowering sea level, intensifying atmospheric circulation, and increasing planetary albedo. Ice sheets interact with ocean water, forming water masses that play a key role in global ocean circulation.

scholarly journals Middle Holocene Climate Oscillations Recorded in the Western Dvina Lakeland

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1611
Author(s):  
Agnieszka Mroczkowska ◽  
Dominik Pawłowski ◽  
Emilie Gauthier ◽  
Andrey Mazurkevich ◽  
Tomi P. Luoto ◽  
...  
Keyword(s):  
River System ◽  
Summer Temperature ◽  
Human Occupation ◽  
Holocene Climate ◽  
Climate History ◽  
Remarkable Feature ◽  
Climate Oscillations ◽  
Climate Fluctuations ◽  
The North ◽  
The North Atlantic Oscillation

Although extensive archeological research works have been conducted in the Serteya region in recent years, the Holocene climate history in the Western Dvina Lakeland in Western Russia is still poorly understood. The Neolithic human occupation of the Serteyka lake–river system responded to climate oscillations, resulting in the development of a pile-dwelling settlement between 5.9 and 4.2 ka cal BP. In this paper, we present the quantitative paleoclimatic reconstructions of the Northgrippian stage (8.2–4.2 ka cal BP) from the Great Serteya Palaeolake Basin. The reconstructions were created based on a multiproxy (Chironomidae, pollen and Cladocera) approach. The mean July air temperature remained at 17–20 °C, which is similar to the present temperature in the Smolensk Upland. The summer temperature revealed only weak oscillations during 5.9 and 4.2 ka cal BP. A more remarkable feature during those events was an increase in continentality, manifested by a lower winter temperature and lower annual precipitation. During the third, intermediate oscillation in 5.0–4.7 ka cal BP, a rise in summer temperature and stronger shifts in continental air masses were recorded. It is still unclear if the above-described climate fluctuations are linked to the North Atlantic Oscillation and can be interpreted as an indication of Bond events because only a few high-resolution paleoclimatic reconstructions from the region have been presented and these reconstructions do not demonstrate explicit oscillations in the period of 5.9 and 4.2 ka cal BP.

Quaternary Mammal Communities: Relevance of the Individualistic Response and Non-Analogue Faunas

2005 ◽  
Vol 11 ◽  
pp. 141-158 ◽  
Author(s):  
Russell W. Graham
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Natural Experiment ◽  
Late Quaternary ◽  
Global Climate ◽  
Land Use Management ◽  
Change Analysis ◽  
Climate Fluctuations ◽  
Core Species ◽  
Mammal Communities

Frequent and repeated climate fluctuations of the late Quaternary serve as a “natural experiment” for the response of species to environmental change. Analysis of the FAUNMAP database documents individualistic shifts in the geographic distributions for late Quaternary mammals. However, because the individualistic response is not necessarily random and because many species share similar niche parameters, it is possible that some species appear to form coherent groups of core species. In reality their dispersals are individualistic with regard to rate and timing. The individualistic response of mammals, as well as that of other organisms, has created late Quaternary communities without modern analogues. This concept has profound implications for the design of biological reserves and for land use management with respect to future global climate change. However, the relevance of non-analogue mammal communities has been challenged by Alroy (1999), who claims that non-analogue associations were not common in the Quaternary and that they appeared to occur in both the Pleistocene and Holocene. Reexamination of his analysis shows that he employed a different definition for non-analogue faunas and that his methods of analyses created artificially low counts of non-analogue communities and consequently an underestimate of their importance.

Regional model assessments of fire risks under global climate changes

2006 ◽  
Vol 411 (2) ◽  
pp. 1485-1488 ◽  
Author(s):  
I. I. Mokhov ◽  
A. V. Chernokulsky ◽  
I. M. Shkolnik
Keyword(s):  
Climate Changes ◽  
Global Climate ◽  
Regional Model ◽  
Global Climate Changes
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