P availability, fine root properties and functional mycorrhizal diversity across Pinus pinaster stands with different productivity in South-western France

Plassard Claude, Meredieu Céline, Bakker Mark, Danjon Frédéric, Trichet Patrick, Guinberteau Jacques, Augusto Laurent, Saur Etienne, Domergue Odile, Galiana Antoine, Prin Yves, Ali M.A., Hinsinger Philippe, Jaillard Benoît, Pellerin Sylvain, Loustau Denis. 2007. P availability, fine root properties and functional mycorrhizal diversity across Pinus pinaster stands with different productivity in South-western France. In : Second International Rhizosphere Conference, Montpellier, France, 26-31 August 2007. s.l. : s.n., Résumé, 180. International Rhizosphere Conference. 2, Montpellier, France, 26 Août 2007/31 Août 2007.

Résumé : The Pinus pinaster forest in South-western France covers 0.9 million hectares with mainly acidic sandy, nutrient-poor spodosols. This forestl produces the fifth of French wood and is characterized by a large variation in productivity. We aimed at linking these variations to the nutritional status of soils and a range of plant root parameters. Twenty-seven sites were selected so as to cover a range of site productivity, phosphorus (P) and water availability levels. These include fertilizer trials and other monitoring sites both on humid and dry environments. Site productivity was estimated from a standard forest inventory operated in 2005. In April and November 2006 eight pairs of sample points were chosen in the tree lines and between the tree lines close to randomly distributed trees. Soil P status (OIsen P and total organic P), amount of fine roots, diversity and phosphatase activities of ectomycorrhizae (ECM) and their associated bacteria were determined in 15x8 cm soil cores. Differences between sites were striking. Grouping samples according to sample position, fertilization regime, stand age or water availability showed that P forms were greater in April than November. Olsen P level was significantly larger only between the tree lines of annually fertilized plots, compared to all other plots. The measured root parameters, i.e. fine root length density (FRLD). specific root length (SRL), vitality of apices. mycorrhizal colonization degree and ECM phosphatase activities were significantly greater in November than April. Only SRL and vitality of apices increased as a response to P fertilization. On the contrary, P-solubilizing capacities of mycorrhizospheric bacteria were greater in control plots with no P fertilizer. ECM pNNPase activities were always measurable and tended to decrease as a response to fertilization. Multivariate statistical analyses of the data will be presented in order to draw the possible relationships between tree productivity, biotic and abiotic factors in the root environment. (Texte intégral)

Classification Agris : F62 - Physiologie végétale : croissance et développement
K10 - Production forestière
P34 - Biologie du sol

Auteurs et affiliations

• Plassard Claude, INRA (FRA)
• Meredieu Céline, INRA (FRA)
• Bakker Mark, INRA (FRA)
• Danjon Frédéric, INRA (FRA)
• Trichet Patrick, CIRAD-SG (FRA)
• Guinberteau Jacques, INRA (FRA)
• Augusto Laurent, INRA (FRA)
• Saur Etienne, ENITAB (FRA)
• Domergue Odile, INRA (FRA)
• Galiana Antoine, CIRAD-BIOS-UMR LSTM (FRA) ORCID: 0000-0002-5293-5049
• Prin Yves, CIRAD-BIOS-UMR LSTM (FRA) ORCID: 0000-0002-3706-0045
• Ali M.A., INRA (FRA)
• Hinsinger Philippe, INRA (FRA)
• Jaillard Benoît, INRA (FRA)
• Pellerin Sylvain, INRA (FRA)
• Loustau Denis, INRA (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/553595/)

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