Southeast Asian Giant Trees Show Surprising Drought Resistance

Giant trees in Southeast Asia possess surprising resilience to drought, comparable to their shorter counterparts. International research, including Spanish participation, has uncovered hydraulic adaptations enabling these giants to transport water up to 70 meters. Previously, scientists believed taller trees were more vulnerable to water scarcity due to the immense difficulty of pumping water from roots to high branches.

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the giant trees of Southeast Asia are as resistant to drought as the shorter specimens, thanks to hydraulic adaptations that facilitate water transport up to 70 meters high.

The study, published in the journal Science, focused on species like Kapur and White Seraya, which can exceed 70 meters in tropical Asian rainforests. The key to their survival lies in the xylem, a microscopic circulatory system. In these towering trees, the xylem widens from the crown to the trunk's base, facilitating water flow. Researchers also found that leaves adapt by altering salt and sugar concentrations to retain more water and sustain photosynthesis.

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the scientific community believed that the tallest trees were much more vulnerable to water scarcity due to the extreme difficulty of pumping liquid from the roots to the highest branches.

To validate these mechanisms, the team monitored 38 trees of five different species in Borneo over two years, assessing their response to an extreme drought during an El Niño event. The findings are considered "good news" because the tallest 1% of the world's trees store over half the carbon accumulated in tropical forests. This suggests that current models may overestimate the risk of drought-related death for these giants.

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the leaves also adapt by modifying the concentration of salts and sugars to retain more water and prolong photosynthesis.

However, the experts caution that if these trees perish, they cease to act as carbon sinks, releasing stored carbon dioxide into the atmosphere and accelerating global warming. The study proposes that these hydraulic survival strategies might be common in other tall species, prompting scientists to advocate for further research in ecosystems like Mediterranean forests.

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good news