Search results for "GLOBAL CHANGE"
showing 10 items of 639 documents
Variability and Uncertainty Challenges in Scaling Imaging Spectroscopy Retrievals and Validations from Leaves Up to Vegetation Canopies
2019
Imaging spectroscopy of vegetation requires methods for scaling and generalizing optical signals that are reflected, transmitted and emitted in the solar wavelength domain from single leaves and observed at the level of canopies by proximal sensing, airborne and satellite spectroradiometers. The upscaling embedded in imaging spectroscopy retrievals and validations of plant biochemical and structural traits is challenged by natural variability and measurement uncertainties. Sources of the leaf-to-canopy upscaling variability and uncertainties are reviewed with respect to: (1) implementation of retrieval algorithms and (2) their parameterization and validation of quantitative products through…
Les hêtraies du Châtillonnais (Côte-d'Or) face au changement climatique.
2013
15 pages; International audience; L'étude traite des hêtraies du Châtillonnais (Côte-d'Or, Bourgogne) face au changement climatique observé. Les données regroupent les séries bourguignonnes de température et de précipitation des stations de Météo France (1989-2009), la carte des hêtraies de l'Institut forestier national (IFN), un modèle numérique de terrain (MNT, SRTM) et quatre indices de vulnérabilité du hêtre identifiés dans la littérature. La méthode repose sur une interpolation fine (mailles de 100 m) de ces indices par régression-krigeage. Les résultats permettent de cartographier les risques actuels.
Vulnérabilité des forêts de douglas du Morvan face au changement climatique : l'expérience de 2003
2010
International audience; Contexte et problématique : Lors de l'été 2003, les forêts bourguignonnes ont subi une sécheresse et une canicule dont l'intensité n'avait jamais été observée. Ce double stress hydrique et thermique a provoqué d'importants dépérissements, en particulier chez le douglas. Compte tenu de l'importance économique de cette essence en Bourgogne et de l'évolution climatique probable, il est nécessaire de suivre la vitalité des peuplements et de comprendre les facteurs de variations de la vulnérabilité des peuplements de douglas face à un type d'aléa dont la fréquence sera très probablement accrue dans les décennies à venir. Données et méthode : Pour cela sont analysées : - l…
A Basic View on Models of Nature and the Concept of “Sustainability”
2010
The discussion below is primarily connected to the challenge of agricultural crop production in western and northern Europe by the global change of climate (Box IV.3), but the ideas are of a general character and could therefore be extended outside this geographical area. We believe that strategic thinking and strategic decisions on agriculture and the way of preparing tactical decisions have to be reconsidered everywhere.
Effects of climate and land-use change on species abundance in a Central European bird community.
2007
Although it is known that changes in land use and climate have an impact on ecological communities, it is unclear which of these factors is currently most important. We sought to determine the influence of land-use and climate alteration on changes in the abundance of Central European birds. We examined the impact of these factors by contrasting abundance changes of birds of different breeding habitat, latitudinal distribution, and migratory behavior. We examined data from the semiquantitative Breeding Bird Atlas of Lake Constance, which borders Germany, Switzerland, and Austria. Changes in the regional abundance of the 159 coexisting bird species from 1980-1981 to 2000-2002 were influenced…
Calcification is not the Achilles' heel of cold-water corals in an acidifying ocean
2015
Ocean acidification is thought to be a major threat to coral reefs: laboratory evidence and CO2 seep research has shown adverse effects on many coral species, although a few are resilient. There are concerns that cold-water corals are even more vulnerable as they live in areas where aragonite saturation (?ara) is lower than in the tropics and is falling rapidly due to CO2 emissions. Here, we provide laboratory evidence that net (gross calcification minus dissolution) and gross calcification rates of three common cold-water corals, Caryophyllia smithii, Dendrophyllia cornigera, and Desmophyllum dianthus, are not affected by pCO2 levels expected for 2100 (pCO2 1058 ?atm, ?ara 1.29), and nor a…
Quelles nuits, pour quels territoires ?
2015
International audience; Quelles nuits, pour quels territoires ?
Coalition building in the UN Security Council
2014
Political coalitions in the international system are still understudied in International Relations theory. This article claims that the formation of and variations in coalitions in the international system are affected by changes in their bargaining power and bargaining environment related to the global leadership cycle and by long-term organisational changes of the international political system. Identifying the Security Council as the institution in which states are more likely to keep their systemic preferences at the institutional level, the article studies the presence, formation and change of coalitions in the international system by testing variations in the behaviour of the Securit…
Competition for resources modulates cell-mediated immunity and stress hormone level in nestling collared doves (Streptopelia decaocto)
2008
International audience; Competitive stress imposed by hatching asynchrony may affect developmental trajectories of offsprings by regulating resource allocation between growth and other fitness-related traits. For instance, the down-regulation of immunity is a commonly observed phenomenon under stressful conditions. However, physiological mechanisms that regulate resources allocation to growth and immune functions in response to competition for resources, as well as inter-sexual differences in physiological strategies, are still poorly investigated. To partially fill this gap, we first conducted a descriptive study on chicks of the collared dove (Streptopelia decaocto), a species producing t…
An Investigation of the Energy Consumption by Information Technology Equipments
2013
The World Wide Web and the rise of servers and PC's data centers have become a major position in the overall power consumption of the world. In order to prevent global warming and ensuing disasters, already Internet-service providers, hosting providers on green power have changed. Even household energy suppliers offer green electricity from renewable energy such as wind , solar, biomass and hydro, which emits no carbon dioxide, to stand against global warming. Only a global change for the information technology can prevent the global -warming. The switch to renewable energy is the beginning of our future and must be pursued as well as the research and development in information and communic…