Cloud Forest Trees Drink Water Using Leaves

Tropical cloud forest trees use not just their roots, but also their leaves to drink water directly from clouds, a new study reveals.

Researchers from University of California, Berkeley, have discovered that the leaves of the tropical montane cloud forests drink water from the clouds when water from the soil is not enough.

Cloud forests in tropical areas are evergreen mountain forests, where the conditions cause the clouds and mist to come in contact with the forest vegetation. The atmospheric environment in cloud forests is characterized by persistent, frequent or seasonal cloud cover at the vegetation level, according to UNEP-WCMC.

Cloud forests experience an annual dry season, which is when the leaves from trees take up water from the moisture of clouds.

For their study, the research team used plastic "leaves" to study the patterns of leaf wetness caused by the clouds in Monteverde, Costa Rica. They also placed miniature sensors on the branches of cloud forest plants to find out whether water was entering the leaves when they were wet.

"The textbooks teach us that water enters roots, moves up the trunk and into the branches, then finally exits the leaves. That's true, but it's not the whole story," Greg Goldsmith, lead author of the study from UC Berkeley, said in a statement.

"With our sensors, we observed water entering the leaves and actually moving back down the branches toward the trunk."

Researchers also noticed that not all trees consumed water from clouds.

They suggested that climate change is causing the clouds, which the trees depend on, to disappear. This could cause a significant impact on the trees which use leaves to drink water from clouds.

"The trees that are drinking the most water through their leaves may be more vulnerable to decreases in cloud cover resulting from rising temperatures," said Goldsmith.

Goldsmith and his research team hope the study will help in further research on the impact of climate change on tropical montane cloud forests.

The findings of the study are published in the journal Ecology Letters.