Search results for "Alpine"
showing 10 items of 71 documents
Geochronology of the medium to high-grade metamorphic units of the Peloritani Mts., Sicily
2003
The Peloritani Mountains are a fragment of an orogen variably attributed to the Alpine or Hercynian orogeny. On the basis of 39 Ar- 40 Ar, U-Pb and Rb-Sr dating, the main metamorphism of the two medium-high grade metamorphic units, the Mela and Aspromonte Units, and most of the thrusting responsible for stacking the orogenic edifice are seen to be Hercynian. The main thrusting of the Aspromonte Unit over the lower grade units took place at 301€2 Ma. Brittle deformation during Tertiary reactivation of Hercynian thrust planes did not generate any rejuvenation of white micas in the studied sector. Our dataset shows a great complexity and we propose to unravel it by considering different levels…
Reliability and effectiveness of Ellenberg’s indices in checking flora and vegetation changes induced by climatic variations
2001
Two methods are proposed to assess the significance of time-spanned local variations of Ellenberg’s indicator values in floristic and phytosociological data sets respectively. Both methods are based on frequencies and averages of the indicator values within and among data sets. Main goal of proposed methods is to determine the threshold above which the observed variations are to be considered significant. In order to relate the observed floristic variations to recent climatic changes, attention was focused on the Ellenberg’s indices dealing with the main climatic variables: heliophany, temperature and precipitation. Study-cases from Zannone Island (Pontine Archipelago, Mediterranean region)…
Dwarf shrub vegetation of rock ledges and clefts in the Pamir Alai Mountains (Middle Asia: Tajikistan)
2016
AbstractThe paper presents the results of phytosociological researches on rocky slope vegetation in Tajikistan with the aim to establish a comprehensive syntaxonomical classification system. Field studies were conducted in 2010-2014 in Pamir Alai ranges and Pamirian plateau. Nearly 500 relevés documenting rock and scree vegetation were made according to the Braun-Blanquet method. Numerical analyses of selected 58 relevés representing dwarf shrub vegetation on rock ledges made it possible to distinguish: Ephedro glaucae- Spiraeion baldschuanicae and Ephedrion regeliano-fedtschenkoi alliances, as well as Spiraeetum baldschuanicae, Rhamnetum coriaceae, Pentaphylloidetum parvifoliae and Pentaph…
Populetum pamiricae ass. nova – an endemic forest association to Pamir in Tajikistan (Middle Asia)
2015
Abstract The floristic structure, distribution and habitat requirements of a forest syntaxon, Populetum pamiricae ass. nova is described. The potential range of the Populetum pamiricae association comprises the mountains of eastern Tajikistan (Pamir Alai Mts), Kashgaria in western China (Kunlun Shan Mts) and north-eastern Afghanistan (Hindu Kush Mts) in Middle Asia. The biotope of this community comprises of high mountain river valleys situated at elevations between 2,500 and 3,200 m above sea level. Phytocoenoses of the Populetum pamiricae association are characterized by the apparent domination in the tree layer of a diagnostic species, Populus pamirica. The tree stand has a mean cover ar…
Late palaeozoic magmatism in the basement rocks Southwest of Mt. Olympos, Central Pelagonian zone, Greece: Remnants of a permo-carboniferous magmatic…
2001
We dated basement rocks from several localities southwest of Mt. Olympos, as well as from a locality near the top of the mountain using the single zircon Pb/Pb evaporation technique. For the samples southwest of the mountain, the ages obtained range from ca. 280 to 290 Ma, with only a few zircon grains being around 300 Ma. By contrast, the sample from near the top of the mountain appears to be slightly younger, with ca. 270 Ma. These ages imply that the granitoids crystallized during Late Carboniferous - Early Permian times, and are therefore younger than the basement gneisses of other regions of the Pelagonian zone, which yielded zircon ages of around 300 Ma (e.g. Yarwood & Aftalion 19…
How to resist subduction: evidence for large-scale out-of-sequence thrusting during Eocene collision in western Turkey
2001
Significant along-strike variations have locked large parts of the Alpine subduction complex in the Eastern Mediterranean in the Eocene, and defined the end of high-pressure accretion in western Turkey. Structural analysis reveals that the Anatolide belt in western Turkey formed under greenschist facies metamorphic conditions in the Eocene when a high-pressure metamorphic fragment of the Adriatic plate (the Cycladic blueschist unit) was thrust onto the imbricated mid-crustal units of the Anatolian microcontinent (the Menderes nappes). The contact between the Cycladic blueschist unit and the Menderes nappes, the Cyclades–Menderes thrust, represents an out-of-sequence ramp which cuts up-sect…
Modelling wet and dry spells for daily rainfall data series: an application to irrigation management in North-West Italy
2016
Rainfall time variability is relevant for agricultural production. The daily time scale is often used in modelling crop and soil water balance. In this work a novel statistical analysis of wet and dry spells is presented, together with an application in an Italian area characterised by a relevant climate spatial variability, due to the presence of both high mountains (e.g.: Mont Blanc) and of the Mediterranean Sea. Statistical analysis of the sequences of rainy days, wet spells (WS), and that of no-rainy days, dry spells (DS), could be carried out separately (as widely applied in the past) or jointly, by introducing the inter-arrival time (IT), representing the time elapsed between two subs…
Convention sur la protection des Alpes et transport en droit français
2009
Juen Philippe. Convention sur la protection des Alpes et transport en droit français. In: Revue Européenne de Droit de l'Environnement, n°1, 2009. pp. 33-64.
Fern-dominated Rock Plant Communities of Tajikistan (Middle Asia)
2015
The results of phytosociological research conducted on the fern vegetation of rock crevices and clefts of the Pamir-Alai Mountains in Tajikistan are presented. During field surveys done in 2010–2013, 78 phytosociological relevés were sampled. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. A synopsis of the fern communities of the montane and high altitude zones in Tajikistan is proposed. In the examined vegetation plots, species of 9 ferns, 58 angiosperms and 13 mosses were recorded. The most frequent ferns were: Cystopteris fragilis, Cheilanthes persica, Asplenium ruta-muraria, Asplenium ceterach, Adiantum capillus-veneris and Cryptogramma stelleri. Six …
Soil moisture variations from boreal forests to the tundra
2023
Soil moisture has a profound influence on life on Earth, and this vital water resource varies across space and time. Here, we explored soil moisture variations in boreal forest and tundra environments, where comprehensive soil moisture datasets are scarce. We installed soil moisture sensors up to 14 cm depth at 503 measurement sites within seven study areas across northern Europe. We recorded 6,138,528 measurements to capture soil moisture variations of the snowless season from April to September 2020. We described the spatio-temporal patterns of soil moisture, and test how these patterns are linked to topography and how these links vary in space and time. We found large spatial variation a…