Huber value implementation in a dynamic vegetation model: implications in hydraulic processes and biomass distribution in the Amazon Forest

• Grant number: 23/16135-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: David Montenegro Lapola
• Grantee: Maria Luiza Busato
• Host Institution: Centro de Pesquisas Meteorológicas e Climáticas Aplicadas à Agricultura (CEPAGRI). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The understanding of the effects of climate change on the Amazon Rainforest is crucial for mitigating the process of decline in its capacity to act as a significant carbon sink. To achieve this, it is necessary to study integrated climatic and vegetation processes, which can be done through the so-called Dynamic Global Vegetation Models (DGVMs). However, the currently used models of this type exhibit shortcomings in representing biomass distribution, due to a generalization in the proportion relations among plant tissues. This generalization is evident in the use of constant values for the ratio between xylem area and leaf area of trees, which, in reality, varies due to hydraulic adaptation to climate change. To improve the representation of this relation, a parameter calculated through climate-dependent values and environmental resource availability can be used. This parameter, known as the Huber value (ratio between xylem area and leaf area), can reflect variations in vegetation structure caused by climate changes and is particularly dependent on values that represent plant hydraulics. Therefore, its implementation should improve the representation of biomass distribution in DGVMs by incorporating the influence of climate on tree survival strategies, which, in turn, determine their carbon allocation patterns. With this in mind, this study aims to investigate the effects of implementing the Huber value in the CAETÊ model (CArbon and Ecosystem functional-Trait Evaluation model), aiming to improve the representation of biomass distribution in the Amazon Rainforest, especially through the simulation of drought scenarios.