Why do plants have roots?
Not all plants have roots. The ones that do are the vascular plants which need to take in nutrients passively by means of capillary action and concentration gradients. The plants need their roots to reach down far enough into the vadose zone to get water during times of the year when there isn’t much rain and the water table is dropping. As already mentioned, roots also stabilize the plant to allow it to grow tall and get sunlight. In many places, competition for sunlight is intense so plants have to grow tall and hold themselves up. Thus, the need for roots.
