Banca de DEFESA: IGOR ARAÚJO DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : IGOR ARAÚJO DE SOUZA
DATA : 26/10/2023
HORA: 09:00
LOCAL: Universidade de Leeds
TÍTULO:

Trees in the Southern Amazon are growing approaching physiological thresholds triggered by hydraulic and thermal failures

PALAVRAS-CHAVES:

Tropical trees; hydraulic stress; extreme drought; resistance to embolism; wood functional traits; hydraulic sensitivity.

PÁGINAS: 80
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia de Ecossistemas
RESUMO:

Increasing drought frequency poses a risk to the future function o tropical trees. Previous studies have found that large tropical trees face greatest mortality risk under drought, but the mechanisms behind this are unclear. Here we investigate whether large tropical trees have different hydraulic traits to smaller conspecifics. We computed xylem hydraulic conductivity from anatomical measurements, and determined xylem resistance to embolism, hydraulic safety margin and wood functional traits for four tree species in southern Amazon in Brazil, across a range of tree heights from saplings to adult trees close to their maximum heights. We found that taller trees within the species exhibit greater hydraulic efficiency and are more vulnerable to embolism and, therefore, more susceptible to drought than lower conspecifics. We also found that wood density and vessel diameter are good predictors of xylem hydraulic vulnerability. Overall, the results suggest that increasing hydraulic vulnerability with height may help to explain patterns of high drought-induced mortality in large trees.

MEMBROS DA BANCA:
Presidente - 606.226.102-44 - DAVID ROBERTO GALBRAITH - ED
Externo à Instituição - CATIA HENRIQUES CALLADO - UERJ
Externo à Instituição - HALINA SOARES JANCOSKI - UNEMAT
Externo à Instituição - JULIANA SCHIETTI DE ALMEIDA - UFAM
Externo à Instituição - 028.588.761-00 - PRISCILA FERNANDA SIMIONI - UENF
Externo à Instituição - ROSANA MARTA KOLB -
Externo à Instituição - ANGELA PIERRE VITORIA - UENF
Externo à Instituição - 986.188.651-68 - SIMONE MATIAS DE ALMEIDA REIS - UNEMAT