51 research outputs found
Photosynthetic quantum efficiency in southâeastern Amazonian trees may be already affected by climate change
Tropical forests are experiencing unprecedented highâtemperature conditions due to climate change that could limit their photosynthetic functions. We studied the highâtemperature sensitivity of photosynthesis in a rainforest site in southern Amazonia, where some of the highest temperatures and most rapid warming in the Tropics have been recorded. The quantum yield (F v /F m ) of photosystem II was measured in seven dominant tree species using leaf discs exposed to varying levels of heat stress. T 50 was calculated as the temperature at which F v /F m was half the maximum value. T 5 is defined as the breakpoint temperature, at which F v /F m decline was initiated. Leaf thermotolerance in the rapidly warming southern Amazonia was the highest recorded for forest tree species globally. T 50 and T 5 varied between species, with one midâstorey species, Amaioua guianensis , exhibiting particularly high T 50 and T 5 values. While the T 50 values of the species sampled were several degrees above the maximum air temperatures experienced in southern Amazonia, the T 5 values of several species are now exceeded under presentâday maximum air temperatures
Reliability and Validity of the Dutch Translation of the Filial Maturity Measure in Informal Caregivers
Pseudomonas aeruginosa: study of Antibiotic Resistance and Molecular Typing in Hospital Infection Cases in a Neonatal Intensive Care Unit from Rio de Janeiro City, Brazil
Application of a double-enrichment procedure for microsatellite isolation and the use of tailed primers for high throughput genotyping
Fine mapping and single nucleotide polymorphism effects estimation on pig chromosomes 1, 4, 7, 8, 17 and X
Reproductive phenology of an herbaceous-subshrub layer of a Savannah (Campo Sujo) in the Cerrado Biosphere Reserve I, Brazil
The influence of seasonality on fish life stages and residence in surf zones: a case of study in a tropical region
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