Urbanization increases gross primary production and biomass of Atlantic forest fragments

Abstract

Urbanization impacts on biomass production and storage in the endangered Atlantic Forest require further investigation seeking effective methods for monitoring carbon flux. Our study compared gross primary production (GPP) and vegetation biomass increment across seasons between urban and non-urban forests of the Brazilian Atlantic Forest. We hypothesized higher GPP and biomass values in the urban forest and during the rainy seasons (spring and summer) compared to the non-urban forest and dry seasons (autumn and winter), respectively. We used two MODIS products which provides GPP and net primary production (NPP) to quantify the photosynthetic activity and biomass of an urban forest in Tijuca National Park (Rio de Janeiro, Brazil) and a non-urban forest of comparable size and climate region between the years 2004 and 2024. We observed higher values of GPP and biomass in the rainy seasons (GPP = 9.5 ± 1.6 g C m⁻² day⁻¹; biomass = 12.3 ± 2.2 g C m⁻² day⁻¹) compared to the dry seasons (GPP = 7.4 ± 1.2 g C m⁻² day⁻¹; biomass = 9.6 ± 1.6 g C m⁻² day⁻¹) in the 20 years. Urbanization and rainy seasons together positively influenced GPP and biomass increase, indicating a synergistic effect of urbanization and rainfall on the production dynamics. We concluded that the primary production of the Atlantic Forest fragments examined was positively influenced by rainfall and urbanization. These factors serve as significant agents in mitigating carbon emissions and enhancing ecosystem services, especially amidst rapid urbanization and climatic changes.