| 1. |
- Adroit, Benjamin, et al.
(författare)
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Are morphological characteristics of Parrotia (Hamamelidaceae) pollen species diagnostic?
- 2022
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Ingår i: Review of Palaeobotany and Palynology. - Amsterdam : Elsevier BV. - 0034-6667 .- 1879-0615. ; 307, s. 104776-104776
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Tidskriftsartikel (refereegranskat)abstract
- Parrotia persica is one of the most notable endemic relict tree species growing in the Hyrcanian forest at the southern Caspian Sea. The recent discovery of sibling species Parrotia subaequalis, occurring in the temperate forests of south-eastern China, offers the opportunity to compare their morphology and ecological preferences and to dig deeper into the paleophytogeographic history of the genus from a perspective. Since pollen morphology of these species would be essential to unravel the origin and evolution of these Arcto-Tertiary species, the present study aimed to investigate whether it is possible to segregate pollen from these two species. Therefore, a detailed combined light- and scanning electron microscopy-based pollen-analysis of each taxon was conducted, the pollen was described, measured, and compared using statistical approaches and principal component analyses to establish unbiased results. The correlation-based principal component analysis achieved for each species shows an overall good superposition of pollen grains measured in equatorial and polar views in the first principal plane, revealing that the P. persica pollen is morphometrically as homogeneous as that of P. subaequalis. Then, the significant difference, mainly driven by lumen density, has been highlighted between the two species. Ultimately, the cross-validation of the resulting two-species linear discriminants classifier shows that based upon this reference dataset, (sub)fossil pollen grain can now be confidently assigned to either of the two species with an 85.8% correct-assignment rate. This opens new doors in the affiliation of fossil Parrotia pollen and suggests that previous pollen records need to be revised.
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| 2. |
- Gurjazkaite, Karolina, 1993-, et al.
(författare)
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Vegetation history and human-environment interactions through the late Holocene in Konar Sandal, SE Iran
- 2018
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Ingår i: Quaternary Science Reviews. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0277-3791 .- 1873-457X. ; 194, s. 143-155
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Tidskriftsartikel (refereegranskat)abstract
- The Jiroft valley, situated on banks of the Halil Rud developed as an important agricultural and trading center during the Early Bronze Age. Known for its famous steatite sculptures and clay pottery, the first settlement in Konar Sandal collapsed around 3rd millennium BCE. A second shorter, but major phase of occupation in the settlement occurred towards the end of 2nd millennium BCE. A 250-cm long peat sequence near the archaeological complex at Konar Sandal was investigated to reconstruct the human environment history using palynological, sedimentological and geochemical data. With a basal age of 4 ka, the core traces the hydroclimatic changes and human activities that started just after large scale abandonment of Konar Sandal and extends from the late Bronze Age to the Mongol invasion. The results show that Jiroft had an arid dry climate dominated by the Saharo-Sindian open pseudo-savanna vegetation. However, due to human clearance and intensified agro-sylvo-pastoral activities, and climatic factors, the land-cover shifted from open xeric scrublands to a more open degraded landscape. The principal human occupation was cereal cultivation and herding. However, it is likely that during the more arid periods, communities retreated and abandoned agriculture, facilitating successional processes. Such droughts occurred around 4.0-3.8 ka and 3.4-2.8 ka and are related to the Siberian Anticyclonic system. Declining Artemisia and shrubs indicate milder climates ca. 3.8-3.4 ka and 2.8-0.6 ka. The latter period that started with the rule of the Persian empires (550-650 BCE), and continued through the Islamic era, coincides with intensive human activities, and the highest degradation of vegetation. (C) 2018 Elsevier Ltd. All rights reserved.
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| 3. |
- Ponel, Philippe, et al.
(författare)
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Novel insights from coleopteran and pollen evidence into the Lateglacial/Holocene transition in Aubrac, French Massif Central
- 2016
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Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182. ; 463, s. 83-102
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to describe the environmental and climate changes that occurred in the mountains of Aubrac at the transition between the Lateglacial and the Holocene, from a comparative analysis of fossil Coleoptera and pollen, and a series of 23 14C dates. The changes affecting the ecological categories of Coleoptera lead to a division of the sequence into 5 beetle assemblage zones (BAZ): the lowermost BAZ A is characterized by extremely poor assemblages (periglacial environment); BAZ B (Oldest Dryas and Lateglacial Interstadial) is marked by regular occurrences of taxa associated with open environments, aquatic taxa associated with running and highly oxygenated water, and cold adapted taxa with relatively low numbers; BAZ C (Younger Dryas) corresponds to two important events: a particular abundance of cold adapted taxa and a marked decrease of running water taxa, beetles associated with herbaceous vegetation and open environments are also well represented; BAZ D (Early Holocene) corresponds to the total disappearance of cold adapted taxa; the transition BAZ C/BAZ D is marked also by a dramatic peak of running water taxa; the uppermost BAZ E (Early/Mid Holocene) is marked by a total absence of running water taxa which are replaced by standing water or taxa tolerant of a range of water conditions, a particular abundance of wetland taxa, and taxa associated with herbaceous vegetation and open environments. Beetle and pollen data suggest that the harsh climatic conditions prevailing in the Aubrac mountains did not allow warm dependent fauna and trees to establish during the Lateglacial Interstadial, at least in the Roustières region, and that wide open landscapes occupied the plateau at that time. The Older Dryas, a cold spell previously recorded at La Taphanel (Cantal), is not visible in the Roustières record, probably because of the higher altitude at Roustières, whereas the Younger Dryas is strongly expressed. During the Holocene, concordant beetles and pollen data enable to reconstruct the rapid recolonization of the plateau by mesophilous trees (Ulmus, Quercus), suggesting the possible presence of refugia to the southern slopes of the Aubrac plateau. Insect/pollen comparisons provide evidence for hydrological changes in the former lake of Roustières and suggest that lacustrine water level changes often used as indicator of precipitation regime changes should be taken with caution.
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| 4. |
- Vaezi, Alireza, et al.
(författare)
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New multi-proxy record shows potential impacts of precipitation on the rise and ebb of Bronze Age and imperial Persian societies in southeastern Iran
- 2022
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Ingår i: Quaternary Science Reviews. - : Pergamon-Elsevier Science Ltd. - 0277-3791 .- 1873-457X. ; 298
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Tidskriftsartikel (refereegranskat)abstract
- The Achaemenids and Sasanian Persian Empires were significant political, economic, and social forces in the Late Iron Age and Late Antiquity Eurasia, respectively, which have left marks on the heritage of the Mediterranean and Middle Eastern world. While attention is often focused on military and political conditions when discussing the prosperity and decline of these imperial powers, their realms, which crossed a variety of environmental settings, were highly dependent on the predictability of rainfall that drove agriculture and effective provisioning. Here, we present a multi-proxy sedimentological, geochemical, and palynological record from a 2.5-m long peat deposit near the excavation site in Konar Sandal near Jiroft in southeastern Iran, covering 4000-850 cal yr BP. Around 3950 cal yr BP a wet period prevailed based on elemental ratios, stable C isotope, pollen, and diagnostic lipids. Between 3900 and 3300 cal yr BP, wet/semi-wet conditions developed with the appearance of Cerealia-type pollen. Dry and windy conditions followed (ca. 3300-2900 cal yr BP), which coincided with the Siberian anticyclones and climatic shifts developing in the Eastern Mediterranean region. Consequently, the Bronze Age settlements around Jiroft, dependent on agriculture, underwent a steady decline. A prolonged wet period followed (ca. 2900-2300 cal yr BP) with the abundance of Sparganium-type pollen and the aquatic lipid proxy (Paq). This change coincided with intensive agricultural practices and the flourishing of the powerful Median and Achaemenid empires. The shift to high Ti/Al ratios coeval with the lowest d13COM values suggests an increase in aeolian activity and dry conditions ca. 2100-1650 cal yr BP. The Jiroft valley again experienced wet conditions between 1550 and 1300 cal yr BP, which overlapped with the economic prosperity of the middle to late Sasanian empire. The paleoenvironmental reconstruction indicates that wet periods and intensive agriculture coincide with the Persian empires zenith, political influence, and economic affluence. Therefore, contextualized and detailed paleoenvironmental records are desirable to explore the interplay of political and climatic factors in the development and fragmentation of the ancient settlements and imperial powers in Eurasian history. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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