INFLUENCE OF NUTRITIONAL DEFICIENCIES ON THE FINE ROOT ARCHITECTURE OF Eucalyptus grandis SEEDLINGS

• Grant number: 18/06335-8
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): August 15, 2018
• Effective date (End): February 14, 2019
• Field of knowledge: Agronomical Sciences - Forestry Resources and Forestry Engineering - Forestry
• Principal researcher: Jean Paul Laclau
• Grantee: Rafael Costa Pinheiro
• Supervisor abroad: Catherine Roumet
• Home Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Research place: Centre d'Ecologie Fonctionnelle & Evolutive (CEFE), France
• Associated to the scholarship: 15/25946-0 - Maximum distance evaluation of nutrient uptake in tropical forest formations using 15N as tracer, BP.DR

Abstract

Root systems play key roles in plant functioning and strongly influence ecosystem services. Many studies show a high plasticity of plant roots to soil environment, both morphologically and functionally, in order to take up soil resources. However, structure-function relationships remain poorly understood for tree root systems. Understanding how fine root architecture can be adjusted in eucalypt seedlings in response to the availability of major nutrients (N, P and K) is needed to improve process-based models as well as sampling methods in ecophysiological studies. Fine root classification in branching orders is a methodology more and more used worldwide in functional ecology but still little used in Brazil. This project aims to gain insight into the capacity of Eucalyptus grandis seedlings to adapt fine root architecture to the availability of N, P and K in the soil, and whether the response is nutrient-specific or not. The study will be conducted in Montpellier in order to use lab facilities and staff experience in analyzing fine root traits. The trial will be set up in pots to with a substrate composed of peat and sand to easily and carefully harvest roots for architecture analysis. Four treatments will be compared: 1) control treatment (+NPK), with concentrations of N, P and K commonly used for the fertilization of E. grandis seedlings in commercial nurseries; 2) a N-deficient treatment (-N); 3) a P-deficient treatment (-P); 4) a K-deficient treatment (-K), with 10% of N, P and K doses commonly applied in commercial fertilization, respectively. Morphological, anatomic, and biochemical traits of first order roots will be evaluated and compared.