Search results for "Climate"
showing 10 items of 4934 documents
A 5500-year oxygen isotope record of high arctic environmental change from southern Spitsbergen
2017
The oxygen isotope composition of chironomid head capsules in a sediment core spanning the past 5500 years from Lake Svartvatnet in southern Spitsbergen was used to reconstruct the oxygen isotope composition of lake water (δ18Olw) and local precipitation. The δ18Olw values display shifts from the baseline variability consistent with the timing of recognized historical climatic episodes, such as the Roman Warm Period, the Dark Ages Cold Period and the ‘Little Ice Age’. The highest values of the record, ca. 3‰ above modern δ18Olw values, occur at ca. 1900–1800 cal. yr BP. Three negative excursions increasing in intensity toward the present, at 3400–3200, 1250–1100, and 350–50 cal. yr BP, are…
Source and Nature of Inhaled Atmospheric Dust from Trace Element Analyses of Human Bronchial Fluids
2011
International audience; Rapid volcanic eruptions quickly ejecting large amounts of dust provoke the accumulation of heavy metals in people living in surrounding areas. Analyses of bronchoalveolar lavage samples (BAL) collected from people exposed to the paroxysmal 2001 Etna eruption revealed a strong enrichment of many toxic heavy metals. Comparing the BAL to the dust composition of southeastern Sicily, we found that only V, Cr, Mn, Fe, Co, and U enrichment could be related to the volcanic event, whereas Ni, Cu, Cd, and Pb contents come from the dissolution of particles of anthropogenic origin. Furthermore, the nature of these inhaled anthropogenic particles was revealed by anomalous La and…
Towards a dendrochronologically refined date of the Laacher See eruption around 13,000 years ago
2020
Highlights • Previous age estimates of the Laacher See Eruptions (LSE) around 12,900 years are still diverging and imprecise. • The combination of dendrochronology, wood anatomy, and 14C measurements holds the potential to establish a precise LSE date. • An absolute calendric date of the LSE would improve the synchronization of European Late Glacial to Holocene archives. Abstract The precise date of the Laacher See eruption (LSE), central Europe’s largest Late Pleistocene volcanic event that occurred around 13,000 years ago, is still unknown. Here, we outline the potential of combined high-resolution dendrochronological, wood anatomical and radiocarbon (14C) measurements, to refine the age …
Observation of intrinsically bright terrestrial gamma ray flashes from the Mediterranean basin
2015
Abstract We present three terrestrial gamma ray flashes (TGFs) observed over the Mediterranean basin by the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) satellite. Since the occurrence of these events in the Mediterranean region is quite rare, the characterization of the events was optimized by combining different approaches in order to better define the cloud of origin. The TGFs on 7 November 2004 and 16 October 2006 came from clouds with cloud top higher than 10–12 km where often a strong penetration into the stratosphere is found. This kind of cloud is usually associated with heavy precipitation and intense lightning activity. Nevertheless, the analysis of the cloud type…
Vegetation of taluses and screes of the high montane and alpine zone in the Pamir Alai Mountains (Tajikistan, Middle Asia)
2015
This paper presents the results of phytosociological research on scree vegetation of the Pamir Alai Mts. In total, 128 phytosociological relevés were made during field studies conducted in 2012–2014, applying the Braun-Blanquet method. Plant communities of mobile and fairly stabilised scree of colluvial cones, aprons and fans, inhabiting mainly the high montane and alpine zone in several ranges (e.g.the Zeravshan, Hissar, Hazratishoh, Darvaz, Rushan and Vanch Mts) are herein described. A hierarchical syntaxonomic synopsis of scree communities at montane and alpine elevations in the Pamir Alai Mts is provided. The collected vegetation samples represent the majority of the variations among th…
Red List of vascular plants of Tajikistan – the core area of the Mountains of Central Asia global biodiversity hotspot
2020
AbstractCentral Pamir-Alai, which is located almost entirely within the area of Tajikistan, is one of the world hotspots of biodiversity, harbouring ca. 4,300 species and 1,400 endemic plants. The first application of the IUCN Red List criteria reveals that among all native species occurring in Tajikistan 1,627 taxa (38.11%) are threatened, including 23 extinct (0.54%), 271 (6.34%) critically endangered (CR), 717 (16.79%) endangered (EN) and 639 (14.96%) vulnerable (VU). Globally, 20 taxa are extinct, 711 (16.65%) threatened, including 144 (3.37%) critically endangered, 322 (7.54%) endangered and 245 (5.73%) vulnerable. As we found positive correlation between human density and the number o…
Distribution of graminoids in open habitats in Tajikistan and Kyrgyzstan
2022
Aims: Landscapes of Middle Asia are exposed to human influence due to long-lasting pastoral tradition, and now are largely dominated by non-forest vegetation. Graminoids perform key ecosystem functions, and constitute an important feed source for livestock. We studied the distribution patterns of graminoids cover under climatic and grazing pressure gradients in different open vegetation types. Study area: Tajikistan, Kyrgyzstan. Methods: 1,525 vegetation plots representing five open vegetation types (mires, salt marshes, tall-forb communities, pseudosteppes and steppes) were extracted from the Vegetation of Middle Asia Database. We assessed the relative cover of graminoid species in each ve…
Reduced emissions from deforestation and forest degradation gender analysis of REDD+ and its potential impact on community resources system : case of…
2013
Climate change is the greatest development challenge of the generation. The anthropogenic origins of the phenomenon are mainly in industrialized countries, while people living in poverty in developing countries are the most affected by the negative impacts and have the least capacity to adapt to the changing conditions. The majority of these people are women. Reduced Emissions from Deforestation and Forest Degradation plus (REDD+) is a climate change policy that enables forest communities in developing countries to be compensated for the carbon that is sequestrated in their forest. REDD+ has been considered to have a high potential to enhance forest biodiversity as well as to bring positive…
Team climate, climate strength and team performance: a longitudinal study
2009
We tested the hypothesis that the relationship between team climate and team performance is moderated by climate strength. The study sample was composed of 155 bank branches, and a two-wave panel design was implemented. We measured four team climate facets (support, innovation, goal achievement and enabling formalization). We obtained two subjective indicators of team performance (ratings provided by team members and by team managers) and a financial indicator of team performance. Seven out of the 12 interaction effects tested were statistically significant and showed the expected sign. When financial team performance was the criterion, only the interaction term was significant. This sugges…
The influence of intra-team conflict on work teams' affective climate: A longitudinal study
2008
We analysed whether relationship conflict mediates the link between task conflict and shared affect at the team level of analysis. Moreover, we tested the hypothesis that the relationship between these two types of intra-team conflict would be moderated by team members' interaction. The sample was composed of 156 bank branches. Data were gathered at two points in time. Two affect dimensions (tension and enthusiasm) were measured. The results obtained supported our hypotheses. Relationship conflict fully mediated the relationship between task conflict and team affect. Team members' interaction about team issues moderated the relationship between task conflict and relationship conflict, so th…