Drought mediated changes in carbon allocation in eucalyptus plantations: a labelling experiment to assess the effects of K fertilisation

• Grant number: 11/09727-5
• Support type: Regular Research Grants
• Duration: January 01, 2012 - December 31, 2013
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Meteorology
• Principal researcher: Osvaldo Machado Rodrigues Cabral
• Grantee: Osvaldo Machado Rodrigues Cabral
• Home Institution: Embrapa Meio-Ambiente. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). Jaguariúna , SP, Brazil
• Assoc. researchers: Ana Paula Contador Packer ; Brigitte Josefine Feigl ; Bruno José Rodrigues Alves ; Carlos Clemente Cerri ; Daniel Epron ; Dominique Gerant ; Jean Paul Laclau ; Jean Pierre Daniel Bouillet ; José Leonardo de Moraes Gonçalves ; Marcelo Zacharias Moreira ; Martial Michel Yoric Bernoux ; Nilza Patrícia Ramos ; Pierrick Priault ; Ricardo de Oliveira Figueiredo ; Sergio Tadeu Meirelles ; Yann Pierre Nouvellon

Abstract

In Brazil, many Eucalyptus plantations are located on potassium-deficient soils and in regions subject to water deficit. The interactions between water and potassium (K) deficiencies on the growth and ecophysiology of Eucalyptus grandis stands are studied in an experiment manipulating water and K at the scale of the ecosystem. A split-plot experiment, with 3 complete blocks and plots of 10 x 12 trees, was set up in 2010 with 4 treatments: two water supply regimes (100% of rainfall and 66% of rainfall, with artificial exclusion from 1700 m2 of transparent plastic sheets) and two types of fertilizations (0 and 4,5 kmol ha-1 of K). Important ecophysiological are monitored over the 3 first years after planting (PhD, Fapesp Nº10/50663-8). Even though this approach will provide a global understanding of the C allocation patterns in response to the environmental conditions, it will not make it possible to understand detailed ecophysiological mechanisms. The present project will use 13C-CO2 applied in situ (pulse labelling) to assess the influence of the environment (water and K availabilities) on the dynamics of C allocation in E. grandis ecosystems. We propose to quantify the fluxes of 13C in the organs of the labelled trees, the microbial biomass and the fluxes of respiration inside and at the surface of the soil after in situ labelling. We plan to label 3 trees per treatment (4 trees per week during 3 weeks) and 13C contents will be quantified in tree compartments after 1, 2, 4, 8, 16 and 32 days. This project is ambitious since the first 13C labelling of trees in natural conditions was carried out in 2009 and such methodology has never been used for tropical tree species. The experiment and the technical staff in the Experimental Station of Itatinga are adequate to ensure the success of the project. The results will have important applications to simulate C budgets in tropical plantation forests in a context of climate change, and to improve the allocation of C in ecophysiological models. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

EPRON, DANIEL; CABRAL, OSVALDO MACHADO RODRIGUES; LACLAU, JEAN-PAUL; DANNOURA, MASAKO; PACKER, ANA PAULA; PLAIN, CAROLINE; BATTIE-LACLAU, PATRICIA; MOREIRA, MARCELO ZACHARIAS; TRIVELIN, PAULO CESAR OCHEUZE; BOUILLET, JEAN-PIERRE; GERANT, DOMINIQUE; NOUVELLON, YANN. In situ (CO2)-C-13 pulse labelling of field-grown eucalypt trees revealed the effects of potassium nutrition and throughfall exclusion on phloem transport of photosynthetic carbon. TREE PHYSIOLOGY, v. 36, n. 1, p. 6-21, JAN 2016. Web of Science Citations: 17.