The water-filled reservoir releases small amounts (around 50 ml per day) of water into the ground by a wick to water the tree and to encourage the tree to develop a root structure.[1] The box acts as a shield for the water in the upper ground, and this water then spreads down and out instead of being drawn to the surface and evaporated.[3] Both temperature and humidity beneath and inside the box are more stable night and day than without.[2]