EFFECT OF DROUGHT CONDITIONS IN THE AMAZON ON THE RADIAL INCREASE OF POPULATIONS OF Cedrela SPP: AN APPROACH THROUGH VESSEL CHRONOLOGY

• Grant number: 23/01047-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2023
• End date: April 30, 2024
• Field of knowledge: Agronomical Sciences - Forestry Resources and Forestry Engineering
• Principal Investigator: Mario Tommasiello Filho
• Grantee: Michelle Tamires Araujo Fernandes
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 18/01847-0 - DendroGrad: Tree-rings, wood anatomy and hydraulic traits do evaluate long-term CO2-fertilisation effects across environmental gradients on three tropical tree species, AP.JP

Abstract

The Amazon Rainforest naturally suffers from periods of drought, mainly when the El Niño phenomenon occurs. However, with the worsening climate change, influenced by anthropic activities, the intensity and frequency of droughts have increased, causing changes in forest ecosystems and their services. Trees are important biological indicators of climate change because they show significant changes in its anatomical structure in response to variations in precipitation and temperature. This property is reflected in the width of the growth rings and in the characteristics of the xylem cells. Especially, vessel elements respond to variations in the environment by adjusting their diameter and thickness to meet a given water availability. Species of the genus Cedrela have the characteristic of showing variation in the distribution and diameter of vessels along the growth ring, which makes this cellular structure an important proxy for water availability in the environment. In this study, we aim to construct chronologies of vessels from the growth rings of species of the genus Cedrela (Meliaceae) with distribution in the Amazon in order to investigate the effect of ecological and climatic variations on the anatomy of wood and to understand the ecophysiological responses of trees to them. The results can help in the interpretation of dendrochronological studies, providing essential information about intrinsic phenomena involving ecology, plant physiology and climate. This information is essential for the development of forest conservation strategies in a scenario of more frequent climate changes in which trees undergo accelerated adaptation processes.