Every day, about one quadrillion gallons of water are silently pumped from the ground to the treetops. Earth’s plant life accomplishes this staggering feat using only sunlight. It takes energy to lift all this liquid, but just how much was an open question until this year.
Researchers at UC Santa Barbara have calculated the tremendous amount of power used by plants to move water through their xylem from the soil to their leaves. They found that, on average, it was an additional 14% of the energy the plants harvested through photosynthesis. On a global scale, this is comparable to the production of all of humanity’s hydropower. Their study, published in the Journal of Geophysical Research: Biogeosciences(link is external), is the first to estimate how much energy goes into lifting water up to plant canopies, both for individual plants and worldwide.
“It takes power to move water up through the xylem of the tree. It takes energy. We’re quantifying how much energy that is,” said first author Gregory Quetin(link is external), a postdoctoral researcher in the Department of Geography. This energy is in addition to what a plant produces via photosynthesis. “It’s energy that’s being harvested passively from the environment, just through the tree’s structure.”
Read more at: University of California - Santa Barbara
A stand of quaking aspen pump water up to their canopies in southwestern Colorado. (Photo Credit: Leander Anderegg)