What accounts for the movement of water up the veins of a tall tree?

First of all, the cohesive and adhesive properties of the water molecules fascilitate this. Water molecules stick together and with the walls of the vessels, creating a column of water which doesn t break easily. Moreover the xylem vessels of the tree are very narrow increasing the pressure. Finally, transpiration is taking place as water from the leaves evaporate, thus a continuous osmotic gradient is being created, causing water to be drawn up the tree