Intensification écologique des plantations d'eucalyptus par association d'espèces légumineuses arborées fixatrices d'azote.
This project has been conducted in close relationship with the ANR-Systerra « Intens&Fix » project.
A global increase in wood demand is observed worldwide that is more and more satisfied by forest plantations and especially, in Brazil, by eucalypt plantations (EP). However, their ability to meet wood demand is limited by competing land uses and their sustainability is a major concern with regard to serious long-term N and P deficits. Introducing N2-fixing species in FP may increase stand production, and N and P availability in the soil. The project proposes innovative alternatives to pure EP to provide high and sustainable level of wood production with reduced fertilizer applications, and positive environmental impacts. The project develops an experimental approach on mixed plantations of Eucalyptus sp. and Acacia mangium in experimental stations and a network of trials in commercial companies. The study links water, C, N and P cycles, and the ecological processes involved in their regulation, within both pure and mixed EP. The biological interactions within and between the components of the system (trees, micro-organisms, soil) are studied and quantified with respect to the use of natural resources. The project contributes to the production of refined methodological techniques, documentation of competition/facilitation mechanisms for N and P bioavailability, and provides ecological intensification - based silviculture, adapted for large areas of EP in Brazil.
The production of Eucalyptus plantations must increase in a sustainable way, through innovative practices that are attractive for stakeholders. The overall objective of the project was the ecological intensification of Eucalyptus plantations through the association of the N2-Fixing-tree Acacia mangium to increase Eucalyptus plantations productivity and soil N and P availability. The specific objective was to address the inter- and intra-specific biophysical interactions within Eucalyptus plantation mixed with A. mangium.
The balance between positive and negative interactions drives wood production and C allocation among tree compartments. Lasting N facilitation and complementarity between species in mixture of Eucalyptus and Acacia mainly depends on the absence of water deficit. Nitrogen and P soil functioning and soil biodiversity rapidly change after A. mangium introduction.
Bachega L.R., Bouillet J.P., Piccolo M.C., Saint-André L., Bouvet J.M., Nouvellon Y., Gonçalves J.L.M., Robin A., Laclau J.P., 2016. Decomposition of Eucalyptus grandis and Acacia mangium leaves and fine roots in tropical conditions did not meet the Home Field Advantage hypothesis. Forest Ecology and Management. 359, 33-43.
April 2012 - March 2016
- International Paper
Jean-Pierre Bouillet, Eco&Sols, Cirad Brazil