Climate change and its implications on carbon dynamics in mangrove soils

• Grant number: 22/10932-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2022
• End date: August 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Hermano Melo Queiroz
• Grantee: Guilherme Isidoro Sanches
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Mangroves are coastal ecosystems widely recognized for their ecosystem services provided, one of their main services provided is the global warming mitigation due to the great potential for C accumulation, mainly in their soils. Despite this, mangroves are among the ecosystems most impacted by extreme weather events (e.g., reduced rainfall and freshwater inputs on estuarine regions). As a result of climate change is expected a higher frequency of these impacts may affect which may affect in the short and long term, the biogeochemical processes that control the C storage capacity of mangrove soils. In Brazilian Southeast region, lower rainfall rates and significantly more frequent drought events are expected as the main effects of climate change. This scenario can change the biogeochemical characteristics (e.g., reducing conditions, which result in low organic matter decomposition) of mangrove soils, affecting their functioning and, therefore, the main C pool of this ecosystem (i.e., the soil). Thus, it is expected that changes arising from climate change (e.g., reduced rainfall and increased salinity) will reduce the ability of mangrove soils to act as C sinks due to favoring more oxidizing conditions, increasing the soil organic matter (SOM) decomposition, leading to a soil C content decrease. Thus, this work aims to: i) evaluate how the process of rainfall reduction and salinity increase alter the organic C content in mangrove soils; ii) to evaluate how the expected effects alter the SOM stability and the presence of organo-mineral interactions in soil samples subjected to a condition that simulates reduced rainfall and higher salinity levels. For this, an experimental approach will be used (i.e., mesocosms) that will simulate the effects of climate change on the characteristics of mangrove soils. The results of this study will contribute to better predictions about the impacts on these ecosystems and promote subsidies for their conservation in the face of the threats of climate change.