Climate change: Tropical forests could get too hot for photosynthesis
Source: Middle East Insurance Review | Oct 2023
Climate change and rising global temperatures could make tropical forests get so hot that some types of leaves will not be able to carry out photosynthesis according to a new study.
The new study Tropical forests are approaching critical temperature thresholds published in a recent issue of science journal Nature reveals that with the risk of rising temperatures, tropical trees could also face the risk of necrosis in their leaves. This could potentially result in extensive leaf mortality and even the halting of photosynthesis processes.
Tropical trees start experiencing a decline in the photosynthesis process at an average temperature of approximately 46.7 degrees C. The study indicates that forests are approaching critical temperature thresholds sooner than initially anticipated.
It has also been established that leaves can become significantly hotter than the surrounding air temperature. This observation comes from various researches conducted in countries such as the US, Australia and Brazil as a part of the larger study.
Smithsonian Tropical Research Institute scientist and an author of the study Martijn Slot said, “We know that when leaves start to exceed that critical threshold, then the leaves start to die. They turn brown, they can’t contribute to photosynthesis anymore, they can’t transpire anymore. They’re basically not sweating, therefore not cooling themselves.”
The study revealed that tropical plant species could be greatly affected by even a small temperature change, as the tropics are already hot and experience little temperature variation throughout the year. Temperatures rising further could close leaf pores, reduce transpirational cooling and expose leaves to harmful temperatures.
The study found that the combination of climate change and local deforestation may already be placing the hottest tropical forest regions close to, or even beyond, a critical thermal threshold. M