Description du projet
L’influence de la sécheresse sur la dynamique du carbone des réseaux hydrographiques
Le changement climatique est responsable de sécheresses hydrologiques susceptibles d’entraîner l’assèchement des rivières, ce qui affecte la biodiversité et la décomposition de la matière organique (MO). La MO, qui comprend des composés à base de carbone, est transportée par l’écoulement de l’eau et via la dispersion des organismes qui la consomment. Les périodes de sécheresse perturbent le transport et la dispersion de la MO et, par conséquent, le cycle du carbone ainsi que les émissions de CO2. On comprend toutefois assez mal les effets du changement climatique sur l’ensemble du réseau hydrographique. Le projet MetaDryNet, financé par l’UE, examinera les effets de l’assèchement sur le transport de la MO, sur la dispersion des organismes et sur les émissions de CO2 dans les réseaux hydrographiques intermittents, en combinant méta-analyse, expériences de terrain à l’échelle du réseau et modélisation. Ce projet permettra de mieux comprendre comment l’assèchement des réseaux hydrographiques influe sur les ressources et la biodiversité.
Objectif
One of the greatest challenges of the 21st century is to understand and mitigate the effects of climate change on earth ecosystems. Climate change increases the frequency and intensity of hydrological droughts worldwide. In rivers, drying (i.e. the loss of surface water) is a severe disturbance that alters biodiversity and ecosystem functions such as organic matter (OM) decomposition with often negative consequences for ecosystem services (e.g. water purification) and human activities (e.g. water consumption). River networks are an aquatic continuum in a terrestrial matrix in which OM is transported, and organisms disperse laterally: from terrestrial to aquatic environment, vertically: from the riverbed surface to the subsurface and longitudinally: along the network. Drying, modifies OM transport and dispersal by cutting the water continuum, potentially altering an entire river network´s OM decomposition dynamics, and hence carbon cycling and CO2 emissions. Although, much is known about the effect of drying at local scales, very little is known about its effects at the entire river network scale. Only studies done at an appropriate large scale can adequately inform and help to develop an adaptive management that minimizes drying impacts on river ecosystems and human activities. By combining meta-analysis, network-scale field experiments and modelling, MetaDryNet will explore the effects of drying on OM transport and decomposer organism dispersal to determine how drying affects OM decomposition and CO2 emissions in river networks. Using new technologies, novel ecological theories and complex modelling approaches this research is highly innovative and will allow to improve our understanding of how resources and biodiversity are linked in space and time in drying river networks. This project will contribute to advance ecological theories but also offer guidance for river management and conservation under global changes.
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MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinateur
75007 Paris
France