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Changing patterns of eastern Mediterranean shellfish exploitation in the Late Glacial and Early Holocene: Oxygen isotope evidence from gastropod in E…
2016
Abstract The seasonal pattern of shellfish foraging at the archaeological site of Haua Fteah in the Gebel Akhdar, Libya was investigated from the Epipaleolithic to the Neolithic via oxygen isotope (δ 18 O) analyses of the topshell Phorcus (Osilinus) turbinatus . To validate this species as faithful year-round palaeoenvironmental recorder, the intra-annual variability of δ 18 O in modern shells and sea water was analysed and compared with measured sea surface temperature (SST). The shells were found to be good candidates for seasonal shellfish forging studies as they preserve nearly the complete annual SST cycle in their shell δ 18 O with minimal slowing or stoppage of growth. During the ter…
Evaluating ice fabrics using fabric analyser techniques in Sørsdal Glacier, East Antarctica
2011
AbstractIce cores (∼4 m long) obtained from areas of different surface velocities near the terminus of Sørsdal Glacier, East Antarctica, have been investigated using two versions of a fabric analyser (G50). In sections parallel to the flow plane, the microstructure is typically interlocking with elongate grains that parallel air-bubble elongation, X, reflecting their development in an earlier ductile regime. The c-axis fabric patterns vary with respect to X and vary from single–double maxima to asymmetric small-circle girdles oblique to the planar foliation, which can be attributed to a simple shear regime. The siteto-site variations in the c-axis patterns can be related to areas of differe…
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift
2016
Abstract Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise, as the uplift was accompanied by frequent, high-magnitude earthquakes. This can be deduced from strongly deformed layers which are interpreted as seismites. Such seismites have been described from several countries around the Baltic Sea, including Sweden, Germany and Poland. Now similarly deformed layers that must also be interpreted as seismites, have been discovered also in Latvia, a…
Paleoecological constraints on reef-coral morphologies in the Tortonian–early Messinian of the Lorca Basin, SE Spain
2004
Abstract Coral reefs represent one of the main carbonate factories that contributed to the control of the stratigraphic architecture of carbonate platforms, which had a widespread development during the late Miocene in the paleo-Mediterranean area. The late Miocene reef complexes of the Lorca Basin in southeastern Spain are composed of five mixed siliciclastic/carbonate units, middle Tortonian to early Messinian in age. The development of coral reefs probably ceased when the first evaporitic event occurred in the basin centre in the early Messinian. This study mainly focuses on the response of reef communities and the modifications of reef organisation to global and regional parameters. At …
Late Holocene seasonal temperature variability of the western Scottish shelf (St Kilda) recorded in fossil shells of the bivalve Glycymeris glycymeris
2021
Abstract The North Atlantic Ocean and adjacent shelf seas play a crucial role in global climate. To better constrain long-term natural variability and marine-terrestrial linkages in this region, a network of highly resolved marine archives from the open ocean and continental shelves is needed. In recent decades, bivalve sclerochronology has emerged as a field providing such records from the mid- to high latitudes. In May 2014, dead valves and young live specimens of the bivalve Glycymeris glycymeris were collected at St Kilda, Scotland. A floating chronology spanning 187 years was constructed with fossil shells and radiocarbon dated to 3910–3340 cal yr before present (BP), with a probabilit…
Soil physicochemical and microbial drivers of temperature sensitivity of soil organic matter decomposition under boreal forests
2020
Abstract Soil organic matter (SOM) in boreal forests is an important carbon sink. The aim of this study was to assess and to detect factors controlling the temperature sensitivity of SOM decomposition. Soils were collected from Scots pine, Norway spruce, silver birch, and mixed forests (O horizon) in northern Finland, and their basal respiration rates at five different temperatures (from 4 to 28 °C) were measured. The Q10 values, showing the respiration rate changes with a 10 °C increase, were calculated using a Gaussian function and were based on temperature-dependent changes. Several soil physicochemical parameters were measured, and the functional diversity of the soil microbial communit…
Benefits for nurse and facilitated plants emerge when interactions are considered along the entire life-span
2019
The structure of plant communities is often influenced by facilitative interactions where ‘facilitated’ plants benefit from growing associated with ‘nurse’ plants. Facilitation has been mostly studied from the facilitated plant's perspective, and bidirectional effects between nurse and facilitated plants have received less attention. We hypothesized that reciprocal benefits in plant-plant interactions may emerge when interactions are considered along the life-span of the plants involved. Over one spring, we selected five species with similar life-form and growth strategy, and using a full factorial design, we compared different fitness components along the plants’ life-span (seedling establ…
The mapping of the Posidonia oceanica (L.) Delile barrier reef meadow in the southeastern Gulf of Tunis (Tunisia)
2016
Abstract Barrier reefs are among the most important ecomorphosis for Posidonia oceanica meadows and have long been subjected to anthropic pressures. The authors mapped the entire Sidi Rais (northeastern Tunisia) Posidonia oceanica barrier reef by means of remote sensing based on processing a satellite image acquired via Google Earth © software, coupled with field observations obtained by snorkeling. The map thus produced represents the P. oceanica barrier reef in its current state, covering a total area of 156.77 ha, the reef being divided into three distinct sections separated by reverse flows with each section subject to varied anthropic factors and disturbances.
Environmental sensitivity of Neogoniolithon Brassica-Florida associated with vermetid reefs in the Mediterranean Sea
2016
Vermetid reefs in the Mediterranean Sea are increasingly affected by both anthropogenic actions and global climate change, which are putting this coastal ecosystem at risk. The main species involved in building these reefs are two species of intertidal vermetid gastropods and the crustose calcareous alga, Neogoniolithon brassica-florida, which cements the gastropod shells and thus solidifying the reef edges. In the present study, we examined the pattern of distribution in the field and the environmental sensitivity (thermal tolerance, resilience to low pH, high light intensity and desiccation) of N. brassica-florida along the coasts of Sicily and Israel by means of chlorophyll fluorescence …
Do environmental diversity approaches lead to improved site selection? A comparison with the multi-species approach
2008
This paper suggests a new approach to select conservation areas cost-effectively according to the concept of complementarity and representation of focal natural features. The suggested environmental diversity (ED) site selection model maximizes ecological diversity, measured via ordination of the chosen taxa communities. Given their fundamental role in ecosystem functioning, vascular plants are chosen as the indicator taxa. We test the ED indicator model by contrasting it to the conventional site selection indicator (MS model), which maximizes the representation of species number in the indicator taxa. We demonstrate that the ED model is more cost-effective than the MS model. More important…