The overall increase in demand for wood is observed throughout the world, which is supplied by forest plantations (FP) as in the case of Brazil, mainly of eucalyptus plantations (EP). The ability to meet wood demand for is limited by the competition of land use. Thus, increasing or maintaining productivity in the long term is essential. A potential problem is the intensification/increasing of N deficiency during several crop rotations, particularly in short-cycle crops. The inclusion of N2-fixing tree species in eucalypt plantations can contribute to soil enrichment with N, as well as increase P availability in the soil. The objective of this project is to search for innovative alternatives to pure EP, to increase or maintain wood productivity in long term, reducing fertilizer use and environmental impacts. The studies will be conducted in mixed plantations of Eucalyptus sp. and Acacia mangium in two experimental stations (São Paulo and Rio de Janeiro States) and an experimental network established in four forest companies (São Paulo and Minas Gerais States). The project will involve scientists working in ecophysiology, biogeochemistry, soil science, microbiology, forestry and modeling at USP, Embrapa and CIRAD (France). We will study the water cycle, carbon cycle and nutrients (P and N) cycles to better understand the ecological processes involved in regulating hydrologic, microbiological, physiological and nutritional mechanisms. The biological interactions within and between system components (trees, microorganisms, soil) will be studied and quantified in terms of the use of natural resources. The results will contribute to the production of sophisticated methodological techniques to understand the competition mechanisms and facilitate bioavailability of N and P. The results will enable the development and calibration of basic ecophysiological models in mixed plantations of Eucalyptus with Acacia mangium, applicable in other models of eucalyptus association with legumes and appropriate for use in large areas of forest production in Brazil.The objective of this project is investigate the inter- and intraspecific interactions in plantations (mixed stands) of Eucalyptus with Acacia mangium. There are three specific objectives to be developed in three subprojects: i) "Plasticity of the plant and the capture and use of resources (water, light and nutrients)": assess whether A. mangium can improve the N Eucalyptus status and determine the effect of this potential change in the Eucalyptus tree growth, joint productivity of mixed population and soil fertility, ii) "Bioavailability of nutrients and soil ecological function" to evaluate whether A. mangium affects the soil biological functioning, the decomposition of organic matter (OM), the dynamics of soil nutrients (especially N and P) and plant nutrition; iii) "Ecological intensification and scientific value of network experiments": to define the technical bases of ecological intensification of mixed stands and evaluate, in commercial situations, the results obtained from the first two specific objectives.
News published in Agência FAPESP Newsletter about the scholarship: