Adapting
Trees' rootlets (Ultimate branching at the end of the root system, with root hairs.
), which absorb water and nutrients from the soil, are like leaves in the canopy. Just like leaves, they can be long- or short-lived, with some surviving for up to four years and others barely a week. Together, the roots and leaves form a highly flexible system that adapts to the tree's surroundings. When a tree sheds its leaves in response to harsh conditions, in winter in temperate regions for instance, it also gets rid of some of its rootlets.
That's because they would quickly use up more resources than they would contribute. So it's better for the tree to let some of the rootlets perish than to put too much energy into keeping them alive, even though it will have to grow new ones when conditions improve again.
