Soil nutrient variation along a shallow catena in Paracou, French Guiana
van Langenhove, Leandro | Verryckt, Lore | Stahl, Clement | Courtois, Elodie, A | Urbina, Ifigenia | Grau, Oriol | Asensio, Dolores | Peguero, Guille | Margalef, Olga | Freycon, Vincent | Peñuelas, Josep | Janssens, Ivan | Universiteit Antwerpen = University of Antwerp | Ecologie des forêts de Guyane (UMR ECOFOG) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Laboratoire Ecologie, Evolution, Interactions des Systèmes amazoniens (LEEISA) ; Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS) | Forêts et Sociétés (UPR Forêts et Sociétés) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | Département Environnements et Sociétés (Cirad-ES) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | ANR CEBA: ANR-10-LABX-25-01 ANR-11-INBS-0001 | ANR-11-INBS-0001,ANAEE-FR,ANAEE-Services(2011)
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Показать больше [+] Меньше [-]Английский. Tropical forests are generally considered to stand upon nutrient-poor soils, but soil nutrient concentrations and availabilities can vary greatly at local scale due to topographic effects on erosion and water drainage. In this study we physically and chemically characterised the soils of 12 study plots situated along a catena with a shallow slope in a tropical rainforest in French Guiana both during the wet and the dry season to evaluate seasonal differences. Soils along the catena were all Acrisols, but differed strongly in their water drainage flux. Over time, this differential drainage has led to differences in soil texture and mineral composition, affecting the adsorption of various nutrients, most importantly phosphorus. The more clayey soils situated on the slope of the catena had higher total concentrations of carbon, nitrogen, phosphorus and several micronutrients, while extractable nutrient concentrations were highest in the sandiest soils situated at the bottom of the catena. We found that carbon, nitrogen and extractable nutrients all varied seasonally, especially in the surface soil layer. These results are interesting because they show that, even at the local scale, small differences in topography can lead to large heterogeneity in nutrient concentrations, which can have large impacts on plant and microbial community organisation at the landscape level.
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