Nodulation and dinitrogen fixation of legume trees in a tropical freshwater swamp forest in French Guiana

Koponen P., Nygren Pekka, Domenach Anne-Marie, Le Roux Christine, Saur Etienne, Roggy Jean-Christophe. 2003. Nodulation and dinitrogen fixation of legume trees in a tropical freshwater swamp forest in French Guiana. Journal of Tropical Ecology, 19 : 655-666.

Résumé : Nodulated legume trees comprised 43% of the stand basal area in the low, most frequently flooded microsites, and 23% in higher, drier microsites in a tropical freshwater swamp forest in French Guiana. Dinitrogen fixation in Pterocarpus officinalis, Hydrochorea corymbosa and Inga pilosula was confirmed by acetylene reduction assay (ARA), presence of leghaemoglobin in nodules and the 15N natural abundance method. The results for Zygia cataractae were inconclusive but suggested N2 fixation in drier microsites. Nodulated Inga disticha had a 15N-to-14N ratio similar to non-N2-fixing trees, but ARA indicated nitrogenase activity and leghaemoglobin was present in nodules. All bacterial strains were identified as Bradyrhizobium spp. according to the partial 16S rDNA sequences, and they were infective in vitro in the model species Macroptilium atropurpureum. About 35-50% of N in the leaves of P. officinalis, H. corymbosa and I. pilosula was fixed from the atmosphere. Dinitrogen fixation was estimated to contribute at least 8-13% and 17-28% to whole-canopy N in high and low microsites, respectively. Symbiotic N2 fixation appears to provide both a competitive advantage to legume trees under N-limited, flooded conditions and an important N input to neotropical freshwater swamp forests.

Mots-clés Agrovoc : Fabaceae, Fixation de l'azote, nodosité racinaire, Bradyrhizobium, adn, acétylène

Mots-clés géographiques Agrovoc : Guyane française, France

Classification Agris : F62 - Physiologie végétale - Croissance et développement
P34 - Biologie du sol

Auteurs et affiliations

• Koponen P., University of Helsinki (FIN)
• Nygren Pekka, University of Helsinki (FIN)
• Domenach Anne-Marie, CNRS (FRA)
• Le Roux Christine, CIRAD-FORET-PLANTATIONS (FRA) ORCID: 0000-0003-0668-3589
• Saur Etienne, ENITAB (FRA)
• Roggy Jean-Christophe, CIRAD-FORET-UMR ECOFOG (GUF)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/528142/)

Métriques

[ Page générée et mise en cache le 2024-11-18 ]