Science Questions

Where does a tree's water come from?

If a large tree will drink 60 gallons of water per hour, where does all that water come from and where does it go? Connie, Godmanchester

60 gallons per hour is a lot of water.  But it’s estimated that a big tree, such as a 48 foot maple has on average 177,000 leaves, which adds up to a leaf area of 1/6 of an acre.  Each leaf has thousands of tiny pores called stomata on the underside which open up on a nice day and lose water.  They need to do this to pull water up through the roots into the stem and up to the leaves, in a process called transpiration.  All this water must come from ground water, water stored underground.

May 2007