A single Root Trunk functions similar to a Chest, but with 12 storage slots. Items can be stored in a Root Trunk by dragging them onto it or by opening the Root Chest to place them in specific slots.
What makes the Root Trunk special, however, is that it shares its inventory with all other Root Trunks built by the player. Therefore, it is possible to store items in them and transfer them from Root Trunk to Root Trunk instead of carrying them in the player's Inventory.
Unlike regular Chests, Root Trunks do not drop their contents if they are destroyed by Fire, with a Hammer or a Deconstruction Staff. If the last one of them has been destroyed, the items inside them are stored in limbo and can only be accessed again by building another Root Trunk.