scholarly journals The Holocene vegetation dynamics and the formation of Neolithic and present-day Slovenian landscape

2001 ◽  
Vol 28 ◽  
pp. 133-175 ◽  
Author(s):  
Maja Andrič

This paper presents the results of palaeoecological research to investigate the Holocene vegetation development of the Slovenian landscape and the impact of the first farmers upon it. Four study sites were selected and at each site a complete Holocene sedimentary sequence was analysed by using the following techniques: loss-on-ignition, geochemistry, radiocarbon dating, pollen analysis and analysis of micro-charcoal concentration. The results of the study suggest that the Neolithic landscape was probably very dynamic and composed of small patches with different vegetation composition. This vegetation has no present-day analogues. The present-day Slovenian landscape formed only several millennia after the transition to farming.

2021 ◽  
Author(s):  
Laura Dziomber ◽  
Lisa Gurtner ◽  
Maria Leunda ◽  
Christoph Schwörer

<p>Current and future climate change is a serious threat to biodiversity and ecosystem stability. With a rapid increase of global temperatures by 1.5°C since the pre-industrial period and a projected warming of 1.5-4°C by the end of this century, plant species are forced to either adapt to these changes, shift their distribution range to higher elevation, or face population decline and extinction. Today, there is an urgent need to better understand the responses of mountain vegetation to climate change in order to predict the consequences of the human-driven global change currently occurring during the Anthropocene and maintain species diversity and ecosystem services. However, most predictions are based on short-term experiments. There is, in general, an insufficient use of longer time scales in conservation biology to understand long-term processes. Palaeoecological data are a great source of information to infer past species responses to changing environmental factors, such as climate or anthropogenic disturbances.</p><p>The last climate change of a similar magnitude and rate as projected for this century was the transition between the last Ice Age and the Holocene interglacial (ca. 11,700 years ago). By analyzing subfossil plant remains such as plant macrofossils, charcoal and pollen from natural archives, we can study past responses to climate change. However, until recently it was not possible to reconstruct changes at the population level. With the development of new methods to extract ancient DNA (aDNA) from plant remains and next generation DNA-sequencing techniques, we can now infer past population dynamics by analyzing the genetic variation through time. Ancient DNA might also be able to reveal if species could adapt to climatic changes by identifying intraspecific variation of specific genes related to climatic adaptations.</p><p>We are currently investigating a palaeoecological archive from a high-altitude mountain lake, Lai da Vons (1991 m a.s.l), situated in Eastern Switzerland. We are presenting preliminary macrofossil, pollen and charcoal results to reconstruct local to regional vegetation and fire dynamics with high chronological precision and resolution. In a next step, we will use novel molecular methods, in order to track adaptive and neutral genetic diversity through the Holocene by analyzing aDNA from subfossil conifer needles. The overarching goal of this large-scale, multiproxy study is to better understand past vegetation dynamics and the impact of future climate change on plants at multiple scales; from the genetic to the community level.</p><p> </p>


2012 ◽  
Vol 39 (4) ◽  
pp. 252-261 ◽  
Author(s):  
Eva Břízová ◽  
Anna Pazdur ◽  
Natalia Piotrowska

Abstract The paper reports the results of a palynological study of a newly exposed section in the peat sediments of Bezděkov site and its correlation with the previous palaeobotanical studies. The main goal was to elucidate the stratigraphic position and paleogeographic development of fossil peat bog and its environment in the Protected Landscape Area Žďárské vrchy and Železné hory in the Bohemian-Moravian Uplands. The development of peatbog vegetation, as shown by the pollen analysis and radiocarbon dating, took place in the Holocene. Pollen analyses provide evidence for occurrences of wetland assemblages with huge representation of alder wood in all the part of succession, followed by willow near the Cerhovka Brook. Alnus and Abies were the dominant trees during all the time. The deciduous forests consist of elm (Ulmus), oak (Quercus), lime tree (Tilia), maple (Acer) and hazel (Corylus). The mosaic picture of woodland and wetland, which covered this landscape during the Upper Holocene, contrasts with the present day monotonous open lowland. Sediments of the peat bog provide information on the origin and vegetation evolution of this area.


2021 ◽  
Author(s):  
Sylvester Onoriode Obigba

Palynology is a multi-disciplinary field of science that deals with the study and application of extinct, [fossilised] and extant palynomorphs (pollen and spore) and other related microscopic biological entities in the environment. It is divided into palaeo- and actuo-palynology, and provides substantial proxies to understanding past and present vegetation dynamics respectively. With reference to the two geological principles of uniformitarianism and of the evolution of fauna/flora, the distribution of plant indicators across ecological zones, palynomorph morphology and pollen analysis, palynology can be used to identify the change in past and present local and regional vegetation and climate and humans impact on the environment. Other supportive areas of endeavour like radiocarbon dating, sedimentology, taphonomic processes and geomorphology can be used to triangulate inferences drawn from palynological data. Palynomorphs are made of outer cell walls embedded with an inert, complex and resistant biopolymeric signature (called sporopollenin) which helps to facilitate long term preservation in different environmental matrices under favourable conditions, hence its widespread applicability. Palynology have proven to very reliable in reconstructing past vegetation, decrypting essential honeybee plants and understanding the impact of climate on plant population using pollen analysis, for which is the basis for the application of palynology in environmental studies. The application of palynology in climate, vegetation and anthropogenic studies begins with the selection of matrix (sediments from lake, river, ocean, excavation, relatively intact soil profile, bee products), coring or collection of samples, subjection to a series of chemically aided digestion, separation, physical filtration, decanting, accumulating of palynomorphs, microscopic study and ends with the interpretation of recovered information. Literature review on the application of palynology for understanding vegetation and climate interactions is presented in this paper.


2021 ◽  
Author(s):  
Michele Delchiaro ◽  
Giulia Iacobucci ◽  
Francesco Troiani ◽  
Marta Della Seta ◽  
Paolo Ballato ◽  
...  

<p>The Seymareh landslide is the largest rock slope failure (44 Gm<sup>3</sup>) ever recorded on the exposed Earth surface. It detached ∼10 ka BP from the northeastern flank of the Kabir-Kuh anticline (Zagros Mts., Iran) originating the natural dam responsible for the formation of a three-lake system (Seymareh, Jaidar, and Balmak lakes, with an area of 259, 46, and 5 km<sup>2</sup>, respectively). The lake system persisted for ∼3000 yr during the Holocene before its emptying phase due to overflow. A sedimentation rate of 21 mm yr<sup>−1</sup> was estimated for the Seymareh lacustrine deposits, which increased during the early stage of lake emptying because of enhanced sediment yield from the lake tributaries. </p><p>To reconstruct the climatic and environmental impact on the lake infilling, we reviewed the geomorphology of the basins and combined the results with multi-proxy records from a 30 m thick lacustrine sequence in Seymareh Lake. Major analyses comprise grain size analysis, carbon and oxygen stable isotopes of carbonate-bearing sediments, and X-ray diffraction analysis of clay minerals.</p><p>Lake overflowing is largely accepted as the main response to variations in water discharge and sediment supply since the alternation from dry to wet phases enhances sediment mobilization along hillslopes decreasing the accommodation space in the downstream sedimentary basins. In this regard, during the early-middle Holocene, the Seymareh area, as well as the entire Middle East, was affected by short-term climate changes at the millennial-scale, as testified by both paleoecological and archaeological evidence. Indeed, several records from Iranian lakes (i.e., Mirabad, Zeribar, Urmia) well documented the temperature and the moisture conditions of the western Zagros Mountains during the Holocene. During the early Holocene, the precipitation remained low up to 6 ka BP, reaching the driest condition around 8-8.2 ka BP. The impact of this abrupt climate change is evident across West Asia, where the first large villages with domesticated cereals and sheeps disappeared, converting to small hamlets and starting habitat-tracking. As regards the Seymareh area, a more irregular distribution of rainfalls and their increasing seasonality may support rhexistasy conditions, during which the scarce vegetation cover enhances both the hillslope erosion and sedimentation rate in the basins, most likely contributing to the overflow of Seymareh Lake. </p>


2013 ◽  
Vol 9 (4) ◽  
pp. 1629-1643 ◽  
Author(s):  
M. Blaschek ◽  
H. Renssen

Abstract. The relatively warm early Holocene climate in the Nordic Seas, known as the Holocene thermal maximum (HTM), is often associated with an orbitally forced summer insolation maximum at 10 ka BP. The spatial and temporal response recorded in proxy data in the North Atlantic and the Nordic Seas reveals a complex interaction of mechanisms active in the HTM. Previous studies have investigated the impact of the Laurentide Ice Sheet (LIS), as a remnant from the previous glacial period, altering climate conditions with a continuous supply of melt water to the Labrador Sea and adjacent seas and with a downwind cooling effect from the remnant LIS. In our present work we extend this approach by investigating the impact of the Greenland Ice Sheet (GIS) on the early Holocene climate and the HTM. Reconstructions suggest melt rates of 13 mSv for 9 ka BP, which result in our model in an ocean surface cooling of up to 2 K near Greenland. Reconstructed summer SST gradients agree best with our simulation including GIS melt, confirming that the impact of the early Holocene GIS is crucial for understanding the HTM characteristics in the Nordic Seas area. This implies that modern and near-future GIS melt can be expected to play an active role in the climate system in the centuries to come.


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