Evolution of ecosystem services (water yield and biomass production) in a chronosequence of Atlantic Forest regeneration, Serra do Mar and Mantiqueira

Abstract

In face of the important role of forests in providing climate and water regulation services, a number of forest conservation and recovery actions have been taken in Brazil. Among them, we highlight the Mata Atlântica Connection Project, an initiative of the Global Environmental Facility (GEF) and Brazilian Ministry of Science and Technology and Innovation (MCTI), in partnership with the Environment Secretariat of the State of São Paulo, to which this proposal is linked. Although the environmental value of preserved forests is very high, there are still considerable uncertainties about the evolution of water regulation services throughout a forest succession. While most studies suggest that high forest evapotranspiration rates would lead to a decrease in surface and subsurface water sources, recent studies indicate that an adequate forest cover could favor the storage of water in the soil, which is required for plant metabolic activities and atmospheric demands, and groundwater recharge. Considering this matter as an important scientific and environmental management issue, this proposal aims to answer the following scientific questions: what is the amount of water that is required to increase a specific amount of aboveground biomass of native species of the Atlantic Forest and also of pine and eucalyptus growing in this area? what is the potential of the forests to contribute to store, and eventually exceed, the amount of water required for their own maintenance and development and potentially contribute to groundwater recharge? How do these properties vary across different stages of a forest regeneration process? The answers to these and other questions will be obtained by in situ measurements of the water balance variables and aboveground biomass along chronosequences of Atlantic Forest recovery. Complemented with analyzes from computational models of the soil-plant-atmosphere interactions, the results obtained here will be translated into products that allow decision makers to estimate the amount of water required for the various reforestation projects, as well as to consider the potential accumulation of soil water resulting from these projects, which could be translated into local economical growth from payment for ecosystems services contributing to climate and water regulation. (AU)