A better understanding of mud cracking processes gained from in situ measurements on an intertidal mudflat in French Guiana

Autor: Gardel, Antoine, Proisy, Christophe, Lesourd, Sandric, Philippe, Sylvie, Caillaud, Jacinthe, Gontharet, Swanne, Anthony, E. J., Brutier, L.
Přispěvatelé: Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Centre National de la Recherche Scientifique (CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut national des sciences de l'Univers (INSU - CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université du Littoral Côte d'Opale-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: Journal of Coastal Research
Journal of Coastal Research, 2009, SI 56 (1), pp.424-428
Journal of Coastal Research, Coastal Education and Research Foundation, 2009, 1 (SI 56), pp.424-428
Journal of Coastal Research, Coastal Education and Research Foundation, 2009, SI 56 (1), pp.424-428
ISSN: 0749-0208
1551-5036
Popis: International audience; Recent work has revealed that desiccation processes can occur over elongated off-shore mud bars that form on Amazon-derived mud banks. Once mud cracks appear there, opportunistic mangroves, i.e. Avicennia germinans, commence the colonization process. Through the advantage of buoyancy of the mangrove propagules which can be trapped by the mud cracks, propagules can establish sometimes 1-2 kilometres offshore of the adult colonies. In a few months, these pioneer colonies become new sources of propagules, promoting rapid ecosystem expansion. Thus, mud cracking may be seen as an important factor in mangrove resilience. To investigate this phenomenon, a field experiment was conducted during the 2008 equinoctial spring tide in French Guiana in a study area located on the landward face of an elongated mud bar. A digital elevation model (DEM) was computed from DGPS and high-resolution laser station data. Meteorological data including air temperature and humidity, wind speed and orientation, rainfall, solar radiation, temperatures of the mud surface and at a depth of 30-cm, were recorded. Additionally, the water content of the upper mud layer was monitored along a topographic transect. An installed camera took instant photographs every half hour. Preliminary results show that climatic conditions are not the main parameter controlling the desiccation process. Strengthening and consolidation of mud are mainly controlled by mud elevation (water loss by draining) and by the local tidal signal (determinant in spatial behaviour). The DEM enabled computation of the tidal frequency emersion signal, an important tool in analyzing the spatio-temporal patterns of mud cracking and mangrove colonization.
Databáze: OpenAIRE
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