Peat bog and alluvial deposits reveal land degradation during 16th and 17th century colonisation of the western Carpathians (Czech Republic)

Wallachian (shepherd) colonisation of the upper parts of Carpathians, the second largest mountain range in Europe, provides a unique opportunity to study human-induced ecological changes and subsequent sediment mobilisation within slope and fluvial systems. The Wallachians came to the nearly pristine landscape in the Czech part of the Western Carpathians during the 16–17th Century bringing large scale deforestation and grazing to the upper parts of its ridges. Despite the importance of this event, there is a lack of high-resolution multi-proxy reconstructions to help to decipher the relative influence of anthropogenic and climate factors on this landscape. Here we provide a ca. 2.1 kyr record obtained from a peat bog where, using chronological, sedimentological and pollen analyses, we were able to differentiate between environmental conditions before, during and after colonisation. Prior to colonisation, climate deterioration following the onset of Little Ice Age caused changes in forest composition and erosion events (causing a ~AD 0–1500 gap in the record). Abrupt human-induced deforestation detected in the pollen record, together with the abundant fine-grained minerogenic content of peat deposits between AD ~1640 and AD 1870, correspond to increased runoff and sheet erosion on slopes; enhanced by Little Ice Age climate deterioration. The sedimentary record in alluvial deposits downstream indicates that the colonisation of the mountain slopes in this region not only had a local effect on soil degradation, but it also increased the net aggradation of overbank deposits within valley floors. After reforestation, net aggradation was replaced by river incision into alluvia

How warm? How wet? Hydroclimate reconstruction of the past 7500 years in northern Carpathians, Romania

As natural and anthropogenic ecosystems are dependent on the local water availability, understanding past changes in hydroclimate represents a priority in research concerning past climate variability. Here, we used testate amoebae (TA) and chironomid analysis on a radiocarbon dated complex of small pond and peat bog sediment profiles from an ombrotrophic bog (Taut Muced, northern Carpathians, Romania) to quantitatively determine major hydrological changes and July air temperature over the last 7500 years.Wet mire surface conditions with a pH between 23 and 4.5 were inferred for the periods 4500-2700 and 1300400 cal yr BP by the occurrence of Archerella flavum, Amphitrema wrightianum and Hyalosphenia papilio. Dry phases in mire surface conditions and a pH between 2.5 and 5 were inferred for 7550-4500, 2750-1300 and 0 cal yr BP-present by the dominance of Nebela militaris, Difflugia pulex and Phryganella acropodia. The quantitative reconstruction of mean July temperature based on the chironomid communities suggests low summer temperatures for the periods 6550-5600, 4500-3150 and 1550-600 cal yr BP, while periods of slightly higher summer temperatures were observed for 5600-4500,3150-1550 and 100 cal yr BP-present. There is a generally good agreement between drier phases of the peat surface conditions with higher July temperature, suggesting that temperature may have been a controlling factor for water table fluctuation.Our quantitative reconstructions, among the first for central eastern Europe, show a relatively good agreement with other palaeohydrological studies from central eastern Europe, but contrast with others estimates from north-west Europe. Another important aspect of our study is that it provides valuable information on changes in local hydrology and the potential effect of the mean summer temperature over these changes. (C) 2017 Elsevier B.V. All rights reserved

European pollen-based REVEALS land-cover reconstructions for the Holocene: methodology, mapping and potentials

Abstract. Quantitative reconstructions of past land cover are necessary to determine the processes involved in climate–human–land-cover interactions. We present the first temporally continuous and most spatially extensive pollen-based land-cover reconstruction for Europe over the Holocene (last 11 700 cal yr BP). We describe how vegetation cover has been quantified from pollen records at a 1∘ × 1∘ spatial scale using the “Regional Estimates of VEgetation Abundance from Large Sites” (REVEALS) model. REVEALS calculates estimates of past regional vegetation cover in proportions or percentages. REVEALS has been applied to 1128 pollen records across Europe and part of the eastern Mediterranean–Black Sea–Caspian corridor (30–75∘ N, 25∘ W–50∘ E) to reconstruct the percentage cover of 31 plant taxa assigned to 12 plant functional types (PFTs) and 3 land-cover types (LCTs). A new synthesis of relative pollen productivities (RPPs) for European plant taxa was performed for this reconstruction. It includes multiple RPP values (≥2 values) for 39 taxa and single values for 15 taxa (total of 54 taxa). To illustrate this, we present distribution maps for five taxa (Calluna vulgaris, Cerealia type (t)., Picea abies, deciduous Quercus t. and evergreen Quercus t.) and three land-cover types (open land, OL; evergreen trees, ETs; and summer-green trees, STs) for eight selected time windows. The reliability of the REVEALS reconstructions and issues related to the interpretation of the results in terms of landscape openness and human-induced vegetation change are discussed. This is followed by a review of the current use of this reconstruction and its future potential utility and development. REVEALS data quality are primarily determined by pollen count data (pollen count and sample, pollen identification, and chronology) and site type and number (lake or bog, large or small, one site vs. multiple sites) used for REVEALS analysis (for each grid cell). A large number of sites with high-quality pollen count data will produce more reliable land-cover estimates with lower standard errors compared to a low number of sites with lower-quality pollen count data. The REVEALS data presented here can be downloaded from https://doi.org/10.1594/PANGAEA.937075 (Fyfe et al., 2022). </jats:p

A 9000 year record of cyclic vegetation changes identified in a montane peatland deposit located in the Eastern Carpathians (central-Eastern Europe): Autogenic succession or regional climatic influences?

We present a high-resolution, continuous plant macrofossil remains record complemented by a pollen sequence from Tăul Muced bog, in the Eastern Carpathian Mountains (Romania). The record spans the last 9000 years and we test whether peatland development in the Eastern Carpathians is linked to climate change or to autogenic succession. We find that Sphagnum magellanicum was the dominant peat-forming species for ca. 8000 years but we also identify ten phases of increased representation of Eriophorum vaginatum at approximately 8100, 7550, 6850, 6650, 5900, 4650, 3150, 1950, 1450, 750 cal yr. BP. Visual inspection and wavelet analysis show that the episodic increases in the relative abundances of Eriophorum vaginatum were simultaneous with decreased abundances of Sphagnum magellanicum and Sphagnum angustifolium. Comparison with published palaeoclimatic records in this region suggests that these cyclical successions of S. magellanicum and E. vaginatum appear to be primarily a result of climate changes, with E. vaginatum developing mainly during dry phases and S. magellanicum during wetter periods. We therefore suggest that the development of this peatland was largely influenced by changing climatic conditions, although the role of autogenic plant succession cannot be excluded. Our results show the value of ombrotrophic peat deposits as archives of past climate change

New business models for state companies in the oil industry

In the scientific literature business models are defined as architecture of the value creation, profit formula, key processes and key resources. For the oil industry there is a need to develop new business models that have to describe the specificity of this industry and to take into consideration the new objectives after the global oil crisis. Although crude oil price has dropped dramatically since second quarter 2014, OPEC raised crude output to the its highest value in more than three years as it pressed on with a strategy to protect market share and pressure competing producers. The objective of this article is to identify and promote new business models for state companies in the oil industry. The research methodology is based on case studies that present and analyze the business models in two of the main oil producers Iran and Iraq, where the state companies are playing an important role in this industry. The subject is relevant because the business models for state companies in the oil industry have to be modified after the oil crisis and these are not real analysed in the scientific literature. Furthermore, the aspects discussed in the current article represent the main factors that will influence investment prospects of companies in the field in the next decade