Search results for "GLOBAL CHANGE"
showing 10 items of 639 documents
The late Hauterivian Faraoni "Oceanic Anoxic Event" at Río Argos (southern Spain): an assessment on the level of oxygen depletion.
2013
14 pages; International audience; An integrated study of multiple geochemical proxies (TOC, δ13Ccarb, trace metallic elements, iron speciation) on the late Hauterivian Faraoni Oceanic Anoxic Event has been performed along the hemi-pelagic section of Río Argos (south-eastern Spain) in order to better constrain the environmental perturbations linked to this event in the Subbetic domain. In the studied section, the TOC is relatively low (b0.5 wt.%) except for one sample at the base of the Faraoni horizon, where it reaches 1.5 wt.%. The δ13Ccarb signal is characterized by a minor long-term increase, primarily attributed to an enhanced organic matter burial. However, both organic and isotopic si…
Holocene climate variability of the Western Mediterranean: Surface water dynamics inferred from calcareous plankton assemblages
2020
A high-resolution study (centennial scale) has been performed on the calcareous plankton assemblage of the Holocene portion of the Ocean Drilling Program Site 976 (Alboran Sea) with the aim to identify the main changes in the surface water dynamic. The dataset also provided a seasonal foraminiferal sea surface water temperatures (SSTs), estimated using the modern analog technique SIMMAX 28, and it was compared with available geochemical and pollen data at the site. Three main climate shifts were identified as (1) the increase in abundance of Syracosphaera spp. and Turborotalita quinqueloba marks the early Holocene humid phase, during maximum summer insolation and enhanced river runoff. It i…
Climate change and Mediterranean seagrass meadows: a synopsis for environmental managers
2014
12 páginas, 3 figuras
Saving the pharmacy of the sea: How does global change affect species with bioactive potential in the Mediterranean?
2020
Several marine species in the Mediterranean produce molecules with bioactive potential that could be used to develop new drugs (antibiotics, antifungals, antivirals, and antitumourals). Different human activities such as pollution, marine recreation, and fishing, as well as climate change, threaten and even endanger some of these species. These vulnerable species with bioactive potential must be protected, especially in marine reserves, not only because they are valuable components of marine ecosystems, but also because they are a potential source of molecules with pharmacological properties that are currently being researched for the creation of new drugs.
Climate change, marine policy and the valuation of Mediterranean intertidal ecosystems
2011
This commentary describes a gap in the qualitative and quantitative knowledge of the provision of benefits to humans from the intertidal ecosystems of the Mediterranean and offers a framework for quantification of the benefits provided by these systems. The identification of such benefits, understanding their spatial distribution and their subsequent quantification will be critical to the design of policy responses to future climate change, sea level rise and seawater acidification. A baseline understanding of the current state of ecosystem functions, as well as of the provision of related ecosystem services, is therefore needed. Further, researchers must strive to generate forecasts of the…
Evaluating anthropogenic impacts on naturally stressed ecosystems: Revisiting river classifications and biomonitoring metrics along salinity gradients
2019
Naturally stressed ecosystems hold a unique fraction of biodiversity. However, they have been largely ignored in biomonitoring and conservation programmes, such as the EU Water Framework Directive, while global change pressures are threatening their singular values. Here we present a framework to classify and evaluate the ecological quality of naturally stressed rivers along a water salinity gradient. We gathered datasets, including aquatic macroinvertebrate assemblages and environmental information, for 243 river locations across the western Mediterranean to: a) gauge the role of natural stressors (salinity) in driving aquatic community richness and composition; b) make river classificatio…
Zonation by ammonites and foraminifers of the Vraconnian-Turonian interval: A comparison of the Boreal and Tethyan domains (NW Europe / Central Tunis…
2008
International audience; Since the end of the 19th century the interval comprising the uppermost Upper Albian, the Cenomamian, the Turonian and the basal Coniacian has been subdivided, first into ammonite zones, then, beginning in the middle of the 20th century, into zones of planktonic foraminifera. These two groups, one macrofossil, the other microfossil, are particularly effective for bio-chronostratigraphy thanks to their rapid rates of evolution. But differences in the faunal makeup between the Boreal domain (northwestern Europe) and the Tethyan domain (Mediterranean) have for a long time hindered precise correlation of the two domains. Today, in a time interval covering about 16 millio…
Monsoon onset over Sudan-Sahel: Simulation by the regional scale model MM5.
2006
[1] The Mesoscale Model MM5 is used to study the regional features of the West African Monsoon onset. In order to increase the results, simulations are carried out for eight consecutive seasons (March to September) of the years 1994 to 2001. The results show that the model can reproduce the dynamical features of the monsoon in a reasonably good manner but the seasonal cycle seems enhanced. It is hypothesized that overestimated rainfall amounts could be related to a poor representation of the land surface characteristics. Nevertheless, the mean simulated monsoon onset dates are similar to those find in the CMAP data set. The onset is characterized by an apparent increase in zonal flow that c…
Platform GenoSol: a new tool for conserving and exploring soil microbial diversity
2009
International audience; Soils are the principal reservoirs of microbial diversity and represent a core component of terrestrial ecosystems. There is an increasing demand for assessing the impact of agricultural and industrial practices on the environment at large scales in a context of global change. To address this demand, taxonomic and functional diversity of soil microbial communities, and their stability over time need to be characterized for predicting soil quality upon human activities, the evolution of this quality being expected to affect environment quality and public health. Recent methodological progresses have led to the development and automation of molecular biological tools (…