The roots bring nutrients and water from the ground to the tree. The leaves absorb the sun's rays for energy. When plants don't have enough space, they cannot meet their needs. So, the plants protect their resources by using allelopathy. Fire Water Roots Sun Plants need to protect themselves from harm.
Fire is always a threat to plants in the wild.
If trees are too close to each another, fire can spread from one to another very easily. So, trees create space for themselves in order to remain safe. In some areas, there is not a lot of water. The fewer plants there are around you, the more water your roots can pull from the soil. If you are a plant, you need lots of dirt for your roots to grow in.