Nitrogen dynamics in mangrove areas of the Ilha do Cardoso, Cananéia, São Paulo: an isotopic approach

• Grant number: 11/09613-0
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2011
• End date: August 31, 2013
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Rafael Silva Oliveira
• Grantee: Rafael Silva Oliveira
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated researchers: Gabriela Bielefeld Nardoto

Abstract

In order to investigate the nitrogen dynamics in two different mangrove formations (Bosque de Franja e de Bacia) in the State Park of Ilha do Cardoso (Cananéia-SP) we will determine nitrogen stable isotope ratios of the soil-litter-vegetation system. Given that topography (flooding) affects N cycling this issue will be addressed for mangrove in how does N availability vary across the region over different mangrove susbstrate and how these variations in N availability integrated across different mangrove physiognomies. Based on this scenario we will test the hypothesis that the Bosque de Bacia mangrove formation is more limited by nitrogen that the Bosque de Franja mangrove formation, with the former having higher rates of N transformation in the soil, and consequently, higher nitrogen stable isotope ratios in the soil-plant system. Additionally we will measure the N, P, C, NH4 and NO3 concentrations in the topsoil, the redox potential, soil pH, C:N and C:P ratios, but also the tannin and lignin percent of the litter layer. Randomly, 100 topsoil sampling will be taken in every mangrove formation. In every sampling location, the litter layer and surrounding vegetation will be also sampled. In every sample we will determine the C and N stable isotope ratios, and N,C and P concentration. The net mineralization and nitrification rates of the top soil will be also determined. Three extra soil samples (0-50 cm depth) from every mangrove formation will be analyzed for physical-chemical characterization. (AU)