How Trees Adapt to Lack of Water

To survive prolonged water stress, trees must be able to prevent or reduce water loss from certain tissues. Common leaf adaptations include:

1. Thickened waxy layers on leaf surfaces, increases in leaf thickness, and coverings of short hairs (pubescence).

2. Some trees reduce moisture loss by closing their leaf pores (stomates) or decreasing leaf surface or size of new leaves, both of which decrease the amount of water loss.

3. Narrow or spiky leaves of conifers enable them to survive not only the droughts of hot summers but also the cold induced droughts of winter.

4. An extreme form of dealing with water deficits is leaf drop.

5. Some trees adapt to dry conditions by developing massive, spreading roots, or deep roots, either of which can enable the tree to absorb larger volumes of water.