Banca de QUALIFICAÇÃO: Calil Torres Amaral

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : Calil Torres Amaral
DATA : 07/09/2023
HORA: 10:00
LOCAL: Virtual
TÍTULO:

Canopy Temperature in Amazonian Forests: Thermal Regimes
Thermal Regimes, Thermoregulation and Physiological Thresholds

PALAVRAS-CHAVES:

amazon forest, canopy temperature, long-term drought, plant thermoregulation, thermal imaging

PÁGINAS: 37
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia de Ecossistemas
RESUMO:

Climate changes will impose simultaneous and synergistic risks on ecosystems, such as long-term droughts and increased air temperatures. Under water and heat stress conditions, tree canopies may exhibit anomalous thermal responses, possibly affecting key plant functions (i.e photosynthesis, respiration and transpiration). In this study, we associated diurnal canopy temperature (Tcan) measurements obtained from an Unmanned Aerial Vehicle (UAV) thermal camera with environmental variables (i.e air temperature - Tair) at the world's longest-running tropical forest drought experiment, to investigate wheter long-term drought affects tropical tree thermoregulation capability (approximated by the difference between Tcan and Tair, ∆T, and the slope Tcan vs. Tair). Additionally, we modeled ∆T in each plot with respect to abiotic variables to comprehend the shifts in environmental controls over thermoregulation. We observed a decline in thermoregulation capability following 21 years of soil moisture deficit, with the through-fall exclusion (TFE) plot showing an increase in the number of canopies displaying megathermic behavior (slopes > 1.1). However, this did not result in the drought plot having higher Tcan than the control plot throughout the whole day. Surprisingly, canopies in the TFE plot exceeded those in the control plot only after midday, coinciding with an increase in vapor pressure deficit (VPD) and decrease in net radiation (Rnet). Our findings suggest that long-term drought elevates the risk of canopy temperatures remaining near or above thermal limits (i.e., Topt) for an extended duration during the day.  Furthermore, we recommend caution when interpreting the Tcan vs. Tair thermoregulation indicator, as it does not capture the variability in ∆T drived by the interplay of environmental variables throughout the day.

MEMBROS DA BANCA:
Presidente - 606.226.102-44 - DAVID ROBERTO GALBRAITH - ED
Interno - 220.974.038-08 - PAULO MONTEIRO BRANDO - NENHUMA
Externo à Instituição - THIAGO SANNA FREIRE SILVA - LEEDS