Banca de QUALIFICAÇÃO: IGOR ARAÚJO DE SOUZA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : IGOR ARAÚJO DE SOUZA
DATA : 16/10/2019
HORA: 14:30
LOCAL: Campus de Nova Xavantina
TÍTULO:

RISK OF HIGH TEMPERATURE SURVIVAL OF TREES ON SOUTH-AMAZON EDGE

PALAVRAS-CHAVES:

thermal stress, maximum PSII quantum yield, extreme temperatures, high temperature tolerance, Amazonia-Cerrado transition

PÁGINAS: 48
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia de Ecossistemas
RESUMO:

Understand the temperatures tolerance limits of plant leaves is essential on a warming planet, especially to predict changes in biodiversity, carbon stock, and interactions between vegetation and climate. Studies assessing the thermotolerance of native tree species are rare, which limits the ability to assess the risks associated with global warming. Here we investigated the leaf thermotolerance of coocurrent tree species (Qualea parviflora Mart., Pseudobombax longiflorum (Mart.) A. Robyns, Hymenaea stigonocarpa Mart. ex Hayne e Vatairea macrocarpa (Benth.) Ducke.) in savannas (rocky cerrado and typical cerrado) and a forest (cerradão) on the southern amazonian border, and strategies of leaves temperature regulation and possible responses to future warming. We quantified the 50% loss of photosystem II function, maximum leaf temperature and its variation, air temperature, stomatal conductance and some leaf functional attributes. To assess the impacts of future warming, we quantify the current thermal safety margin and future absolute leaf temperatures. Thermotolerance ranged from 46.7 °C to 50.9 °C between species, and was higher for forest individuals. Individuals with lower maximum leaf temperature presented higher thermotolerance, and we observed that different environmental conditions determine different thermotolerance values. We highlight that savanna-grown individuals, even though they have greater efficiency in leaf heat dissipation, are more vulnerable to extreme high-temperature conditions and therefore more likely to be negatively affected by global warming. We observed that thermal limits of some tropical species are near to the maximum temperatures experienced, which presupposes that these species may be severely affected by rising global temperatures. This vulnerability could lead to unexpected and drastic changes in species composition, structure, distribution and interactions that occur in different environments.

MEMBROS DA BANCA:
Presidente - 82328001 - BEATRIZ SCHWANTES MARIMON
Interno - 82329001 - BEN HUR MARIMON JUNIOR
Externo ao Programa - 200202001 - PAULO SERGIO MORANDI
Externo à Instituição - SIMONE MATIAS DE ALMEIDA REIS - Oxford