Carbon and nitrogen flux in the soil-plant-atmosphere system in urban forests of the city of São Paulo, SP

Abstract

Studies in natural environment have shown the dynamics of carbon (C) and nitrogen (N) in primary and secondary forest in the Amazon and Atlantic Forest, but little is known about these attributes in urban forests in Brazil. The Brazilian cities have grown disorganized with high demographic indexes and serious problems of landscape alteration, a fact that might bring complications to the flow of C and N in natural systems, thus promoting feedback effects that compromise the maintenance of ecosystems. Thus, this work aims to understand some processes of carbon and nitrogen dynamics in urban forests of the metropolitan region of São Paulo. For this, the flow of these elements between the soil-plant-atmosphere system will be evaluated. Among the main expected results are: i) knowing and comparing the aboveground structure and biomass of the tree communities along four urban forests (measuring 1 ha each) located in the center-periphery direction of the city of São Paulo; ii) preliminary understanding the relationship between meteorological variables, litterfall production and decomposition, and tree diameter increase in the studied communities; iii) knowing the flow and comparing the total values of C and N of the plant-soil-atmosphere system from the canopy, litterfall production, litter decomposition, soil stock and CO2, CH4 and N2O emission, as well as the isotopic values (´13C and ´15N (0)) in the different urban forests. This information will help to understand the dynamics of carbon and nitrogen in urban forests and will foster important data in a new greenhouse gas monitoring system of the Brazilian Federal Government body. (AU)