In tropical forests, drought can be deadly, but some trees have evolved a clever workaround. Researchers studying three species of Clusia found that certain trees shift their carbon dioxide intake to nighttime, when temperatures are cooler and humidity is higher. By keeping their stomata—the pores on leaves—shut during the hot day, these trees dramatically reduce water loss.
The strategy, known as crassulacean acid metabolism (CAM), is more common in desert plants like cacti, but its presence in tropical trees highlights an adaptive flexibility. The study compared species with different levels of CAM activity, showing that those with stronger night-time breathing coped better under drought conditions.
This discovery matters for conservation and forestry. As climate change intensifies dry spells, identifying which tree species can switch to night-time carbon uptake could guide reforestation efforts and improve predictions of forest resilience. The source does not mention any conflicting findings, but notes the trait varies among species, suggesting not all tropical trees share this advantage.