Long-term altitudinal change in bird richness in a Mediterranean mountain range: habitat shifts explain the trends

2020 ◽  
Vol 20 (2) ◽  
Author(s):  
José Luis Tellería
Keyword(s):  
Mountain Range ◽  
Bird Richness ◽  
Mediterranean Mountain Range

scholarly journals Erosion assessment in the middle Kali Gandaki (Nepal): A sediment budget approach

2013 ◽  
Vol 46 ◽  
Author(s):  
Monique Fort ◽  
Etienne Cossart
Keyword(s):  
Drainage Basin ◽  
Sediment Budget ◽  
Mountain Range ◽  
Primary Concern ◽  
Stream Power ◽  
Sediment Budgets ◽  
Relative Chronology ◽  
Wide Range ◽  
History Of

Active mountains supply the largest sediment fluxes experienced on earth. At mountain range scale, remote sensing approaches, sediments provenance or stream power law analyses, collectively provide rough long-term estimates of total erosion. Erosion is indeed controlled by rock uplift and climate, hence by a wide range of processes (detachment, transport and deposition), all operating within drainage basin units, yet with time and spatial patterns that are quite complex at local scale. We focus on the Kali Gandaki valley, along the gorge section across the Higher Himalaya (e.g. from Kagbeni down to Tatopani). Along this reach, we identify sediment sources, stores and sinks, and consider hillslope int eractions with valley floor, in particular valley damming at short and longer time scales, and their impact on sediment budgets and fluxes. A detailed sediment budget is presented, constrained by available dates and/or relative chronology, ranging from several 10 kyr to a few decades. Obtained results span over two orders of magnitude that can best be explained by the type and magnitude of erosional processes involved. We show that if large landslides contribute significantly to the denudation history of active mountain range, more frequent medium to small scales landslides are in fact of primary concern for Himalayan population.

scholarly journals Geomorphological evolution of the polish part of the Sudetes - a review of results of recent research

Geografie ◽  
2003 ◽  
Vol 108 (3) ◽  
pp. 191-201
Author(s):  
Piotr Migoń
Keyword(s):  
Mountain Range ◽  
Joint Research ◽  
Landform Evolution ◽  
Geomorphic Evolution ◽  
Synthetic View ◽  
Geomorphological Evolution

This paper presents results of selected geomorphological studies published originally in Poland in the last decade and attempts to show the extent to which they complement or diverge from research carried out in the Czechia. It focuses on long-term landform evolution, the role of planation and differential tectonics, glacial and periglacial processes and identifies the scope for joint research efforts, which ultimately may lead towards a comprehensive, synthetic view of geomorphic evolution of the whole mountain range.

scholarly journals Autogenic versus allogenic controls on the evolution of a coupled fluvial megafan/mountainous catchment system: numerical modelling and comparison with the Lannemezan megafan system (Northern Pyrenees, France)

2016 ◽  
Author(s):  
Margaux Mouchené ◽  
Peter van der Beek ◽  
Sébastien Carretier ◽  
Frédéric Mouthereau
Keyword(s):  
Numerical Modelling ◽  
Temporal Variations ◽  
Tectonic Activity ◽  
Mountain Range ◽  
Stream Network ◽  
Mountainous Catchment ◽  
Isostatic Rebound ◽  
Base Level ◽  
Alluvial Terraces

Abstract. Alluvial megafans are sensitive recorders of landscape evolution, controlled by autogenic processes and allogenic forcing and influenced by the coupled dynamics of the fan with its mountainous catchment. The Lannemezan megafan in the northern Pyrenean foreland was abandoned by its mountainous feeder stream during the Quaternary and subsequently incised, leaving a flight of alluvial terraces along the stream network. We explore the relative roles of autogenic processes and external forcing in the building, abandonment and incision of a foreland megafan using numerical modelling and compare the results with the inferred evolution of the Lannemezan megafan. Autogenic processes are sufficient to explain the building of a megafan and the long-term entrenchment of its feeding river at time and space scales that match the Lannemezan setting. Climate, through temporal variations in precipitation rate, may have played a role in the episodic pattern of incision at a shorter time-scale. In contrast, base-level changes, tectonic activity in the mountain range or tilting of the foreland through flexural isostatic rebound appear unimportant.

New species of Lepidodactylus (Squamata: Gekkonidae) from New Guinea and adjacent islands

Zootaxa ◽  
2019 ◽  
Vol 4651 (2) ◽  
pp. 305-329
Author(s):  
FRED KRAUS
Keyword(s):  
New Species ◽  
Habitat Loss ◽  
New Guinea ◽  
Color Pattern ◽  
Mountain Range ◽  
Small Islands ◽  
Large Island ◽  
Habitat Conversion ◽  
Conservation Concern

I describe five new species of Lepidodactylus from New Guinea or adjacent islands that are members of Brown & Parker’s (1977) phenetic Groups I and II and belong to the clades identified as the L. orientalis, L. pumilus, and L. novaeguineae groups of Oliver et al. (2018a). One of the new species is restricted to an isolated mountain range on New Guinea; the remainder inhabit offshore islands ranging from 3–250 km from New Guinea. These species are distinguished from their congeners primarily by unique combinations of toe lamellar numbers and shape, numbers and distribution of enlarged precloacal/femoral scales and pores, toe webbing, toe width, and color pattern. These clades are ancient, and the ancestor of one of them has been on the East Papuan Composite Terrane for at least 28 MY, highlighting the long-term importance of that former large island in generating regional biodiversity. At least one, and probably three, of the new species are inhabitants of forest interiors; one occupies disturbed coastal areas; and the habitat of the last is currently unsurmisable. All of the new species likely have restricted geographic distributions, with four of them being limited to one or a few small islands. As a result of their small ranges, rapid habitat conversion in the ranges of some of these species, and the threat of further habitat loss in the others, most of these species are of conservation concern although it is uncertain if any of them is under immediate threat. 

scholarly journals Amputation Risk Factors in Severely Frostbitten Patients

2019 ◽  
Vol 16 (8) ◽  
pp. 1351
Author(s):  
Anna Carceller ◽  
Casimiro Javierre ◽  
Martín Ríos ◽  
Ginés Viscor
Keyword(s):  
Tissue Regeneration ◽  
Normal Activity ◽  
Daily Activities ◽  
Cold Chain ◽  
Mountain Range ◽  
Winter Sports ◽  
Work Activities ◽  
Cold Environments ◽  
Optimal Medical Management

In recent years, the incidence of frostbite has increased among healthy young adults who practice winter sports (skiing, mountaineering, ice climbing and technical climbing/alpinism) at both the professional and amateur levels. Moreover, given that the population most frequently affected is healthy and active, frostbite supposes a substantial interruption of their normal activity and in most cases is associated with long-term sequelae. It particularly has a higher impact when the affected person’s daily activities require exposure to cold environments, as either sports practices or work activities in which low temperatures are a constant (ski patrols, mountain guides, avalanche forecasters, workers in the cold chain, etc.). Clinical experience with humans shows a limited reversibility of injuries via potential tissue regeneration, which can be fostered with optimal medical management. Data were collected from 92 frostbitten patients in order to evaluate factors that represent a risk of amputation after severe frostbite. Mountain range, years of expertise in winter mountaineering, time elapsed before rewarming and especially altitude were the most important factors for a poor prognosis.

scholarly journals Extrapolating glacier mass balance to the mountain-range scale: the European Alps 1900–2100

2012 ◽  
Vol 6 (4) ◽  
pp. 713-727 ◽  
Author(s):  
M. Huss
Keyword(s):  
Mass Balance ◽  
Multiple Regression ◽  
Volume Change ◽  
Data Series ◽  
Glacier Mass Balance ◽  
Mountain Range ◽  
European Alps ◽  
Ice Volume ◽  
Area Reduction

Abstract. This study addresses the extrapolation of in-situ glacier mass balance measurements to the mountain-range scale and aims at deriving time series of area-averaged mass balance and ice volume change for all glaciers in the European Alps for the period 1900–2100. Long-term mass balance series for 50 Swiss glaciers based on a combination of field data and modelling, and WGMS data for glaciers in Austria, France and Italy are used. A complete glacier inventory is available for the year 2003. Mass balance extrapolation is performed based on (1) arithmetic averaging, (2) glacier hypsometry, and (3) multiple regression. Given a sufficient number of data series, multiple regression with variables describing glacier geometry performs best in reproducing observed spatial mass balance variability. Future mass changes are calculated by driving a combined model for mass balance and glacier geometry with GCM ensembles based on four emission scenarios. Mean glacier mass balance in the European Alps is −0.31 ± 0.04 m w.e. a−1 in 1900–2011, and −1 m w.e. a−1 over the last decade. Total ice volume change since 1900 is −96 ± 13 km3; annual values vary between −5.9 km3 (1947) and +3.9 km3 (1977). Mean mass balances are expected to be around −1.3 m w.e. a−1 by 2050. Model results indicate a glacier area reduction of 4–18% relative to 2003 for the end of the 21st century.

Long and short time evolution of deep seated gravitational slope deformation: contribution to knowledge of phenomena for the management of alea in the Alpine mountains

2020 ◽  
Author(s):  
Clément Boivin
Keyword(s):  
Time Evolution ◽  
Slope Deformation ◽  
Tectonic Activity ◽  
High Mountain ◽  
Mountain Range ◽  
Short Term ◽  
Future Evolution ◽  
Short Time ◽  
Short Time Evolution

<p>"LONG AND SHORT TIME EVOLUTION OF DEEP SEATED GRAVITATIONAL SLOPE DEFORMATION: CONTRIBUTION TO KNOWLEDGE OF PHENOMENA FOR THE MANAGEMENT OF ALEA IN THE ALPINE MOUNTAINS"</p><p> </p><p>C.Boivin <sup>a</sup>, J.P. Malet <sup>a</sup>, C. Bertrand <sup>b</sup>, F. Chabaux <sup>c</sup>, J. van der Woerd <sup>a</sup>, Y. Thiery <sup>d</sup>, F. Lacquement <sup>d</sup></p><p><sup>a  </sup>Institut de Physique du Globe de Strasbourg – IPGS/DA - UMR 7516 CNRS-Unistra</p><p><sup>b </sup> Laboratoire Chrono-Environnement – LCE / UMR 6249 CNRS – UFC</p><p><sup>c</sup>  Laboratoire d’Hydrologie et de Géochimie de Strasbourg – BISE / UMR 7517 – Unistra</p><p><sup>d</sup>  Bureau de Recherches Géologiques et Minières</p><p> </p><p>          The <strong>Deep Seated Gravitational Slope Deformation (DSGSD)</strong> are defined like a set of rock mass characterized by a generally slow movement and which can affect all the slopes of a valley or a mountain range (Agliardi and al., 2001, 2009; Panek and Klimes., 2016). The DSGSD is identified in many mountains (ex: Alps, Alaska, Rocky Mountains, Andes…) and it can affect both isolated low relief and very high mountain ranges (Panek and Klimes., 2016). This deep instability are identified in many case like the origin zone for important landslide like the example of La Clapière landslide in the Alpes Maritimes (Bigot-Cormier et al., 2005). The DSGSD represent an important object we must understand to anticipate catastrophic landslides.</p><p>          Actually, many factors that could be at the origin or controlling the evolution of DSGSD have been identified such as for example the structural heritage, the climate or the tectonic activity (Agliardi 2000; 2009; 2013; Jomard 2006; Sanchez et al., 2009; Zorzi et al., 2013; Panek and Klimes., 2016; Ostermann and Sanders., 2017; Blondeau 2018). The long-term and short-term evolution of DSGSD is still poorly understood but represents an important point to characterize in order to predict future major landslides. A first inventory of DSGSD began to be carried out by certain studies such as Blondeau 2018 or Crosta et al 2013 in the Alps. These same studies have also started to prioritize the factors controlling the evolution of DSGSD.</p><p>          It is in order to better understand the short-term (<100 years) and long-term (> 100 years) evolution of the DSGSD of the French Alpine massifs and the link with the occurrence of landslides, that this thesis project is developed. The main objective of this project, will be proposed models of the evolution of DSGSD since the last glaciations. But also to propose key interpretations of the future evolution to locate the areas likely to initiate landslides. Two study areas in the French Alpine massifs were chosen because they represent areas of referencing and localization gaps in DSGSD: Beaufortain and Queyras. They have the advantage of having a low lithological diversity making it possible to simplify the identification of the factors influencing the evolution of DSGSD. A geomorphological analysis on satellite data and on the ground is carried out to locate the DSGSD. Several dating (<sup>14</sup>C, <sup>10</sup>Be or <sup>36</sup>Cl) will be carried out to reconstruct the history of these objects and understand the factors that controlled their evolution.</p>

Response of Arizona cypress (Hesperocyparis arizonica) to the Horseshoe Two Megafire in a south-eastern Arizona Sky Island mountain range

2019 ◽  
Vol 28 (1) ◽  
pp. 62
Author(s):  
Andrew M. Barton ◽  
Helen M. Poulos
Keyword(s):  
Seedling Establishment ◽  
New World ◽  
Fire Severity ◽  
Mountain Range ◽  
High Severity ◽  
South West ◽  
Fire Intervals ◽  
Sky Island ◽  
Tecate Cypress

We examined the response of Arizona cypress (Hesperocyparis arizonica) to the 2011 Horseshoe Two Megafire in the Chiricahua Mountains, Arizona, USA. We documented cover type, fire severity, cypress mortality and seedling establishment in 60 plots. In plots subject to severe fire, most mature cypresses were killed, the canopy opened and seedlings established abundantly. These results were consistent across three canyons differing in topography and vegetation. Successful regeneration of Arizona cypress contrasts with low seedling establishment for pines in the same area after the Horseshoe Two Fire, a difference possibly explained by abundant serotinous seed production in cypress or its preference for riparian sites protected from extreme fire. Our results firmly establish Arizona cypress as a fire-sensitive but fire-embracing species that depends on stand-replacing fire for regeneration. Given the fire sensitivity of Arizona cypress, however, recent increases in the frequency of high-severity fires in the south-west USA could pose a threat to the long-term viability of this species by preventing individuals from reaching sexual maturity during fire intervals. This scenario, termed the ‘interval squeeze’, has been documented in tecate cypress (H. forbesii) in California. A drier future with more frequent wildfires could pose serious threats to all New World cypresses.

Massif-wide denudation of the Vosges Mountains (NE France) inferred from in situ 10Be concentrations in stream sediments

2021 ◽  
Author(s):  
Timothée Jautzy ◽  
Gilles Rixhon ◽  
Régis Braucher ◽  
Laurent Schmitt ◽  
Aster Team*
Keyword(s):  
Stream Sediments ◽  
Tectonic Activity ◽  
Mountain Range ◽  
Vosges Mountains ◽  
Eastern Side ◽  
Denudation Rates ◽  
The Alps ◽  
Western Side

<p><span>The Vosges Mountains in NE France belong to the belt of Variscan massifs located in the foreland of the Alps. Despite its rather limited extension barely reaching 6000 km², this range of low mountains peaking at ~1425 m presents three contrasting primary characteristics. Firstly, a bipartite N-S subdivision can be achieved based on the geological basement: whereas the southern part, traditionally referred to as the crystalline Vosges, is composed of a mosaic of Palaeozoic rocks, including igneous (mostly intrusive and secondarily extrusive), metamorphic, and sedimentary rocks, the northern part is much more homogeneous given its Triassic sandstone cover (“sandstone Vosges”). Secondly, a clear E-W topographic gradient characterises the mountain range. By contrast to the steep hillslopes and elevation drops regularly exceeding 600 m (sometimes reaching 900-1000 m) between the summits and the valley floors on the eastern side (Alsace; south-western border of the Upper Rhine Graben, URG), the western side exhibits more gently-sloping hillslopes along with a longer extension (Lorraine; eastern border of the Parisian Basin). This results from the sharp E-W contrast in Late Cenozoic tectonic activity between sustained subsidence in the URG to the east and weak rock uplift characterising the Parisian Basin to the west. Finally, the imprint left by Quaternary climatic fluctuations yielded a N-S gradient: whereas the southern part (roughly covering 80-90% of the crystalline Vosges) hosted abundant valley glaciers and still bears traces of significant glacial erosion (cirques and U-shaped valleys), the northern part (mostly the sandstone Vosges) was void of ice cover.</span></p><p><span>In spite of these advantageous characteristics, very little is known about the Quaternary evolution of the massif, in particular regarding the long-term interactions between denudation</span><span>, lithological control, climatic forcing and tectonic activity. </span><span>Against this background, this contribution aims to present the first data of long-term, massif-wide denudation. Modern stream sediments from 21 river catchments of different size draining the whole massif were thus sampled for </span><span><em>in situ</em></span> <sup><span>10</span></sup><span>Be concentration measurements at the outlet of their mountainous reach. Catchment-wide denudation rates inferred from cosmogenic </span><sup><span>10</span></sup><span>Be will be combined with the analysis of morphometric parameters and structural connectivity resulting from the processing of a high-resolution DEM (5 m). Catchment selection was operated according to the threefold subdivision above: i.e. heterogeneous vs homogenous petrography, tectonically-active eastern side vs “quiescent” western side and glaciated vs unglaciated catchments. We thus test the main hypothesis that the four NE, NW, SE, SW quarters of the Vosges massif shall be characterised by contrasting denudation rates, reflecting the respective role played by the controlling factors on long-term denudation. To our knowledge, this contribution is the first attempt to quantify denudation at the massif scale of a European low mountain range. This is especially relevant as long-term landscape evolution in the Variscan belt, by contrast to the numerous works focusing on denudation in high-mountains ranges (e.g. the Alps), has been regularly disregarded in recent geomorphological studies.</span></p><p><span>*Georges Aumaître, Didier L. Bourlès and Karim Keddadouche</span></p>

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