the shade of the tree is cooler than the shade of a root due to

1. transpiration
2. guttation
3. photosynthesis
4. green leaves

The shade of the tree is cooler than the shade of a root due to transpiration.
Transpirationis the process of water movement through a plant and its evaporation from aerial parts, such as from leaves but also from stems and flowers. Leaf surfaces are dotted with pores which are called stomata, and in most plants they are more numerous on the undersides of the foliage.