Trees do not heal, they compartmentalize infections. This process makes it possible for trees to outlive humans, even when constantly mutilated. So, humans are supposed to be so great because of their big brain that can think, learn, make decisions, and predict events yet to happen. The basic advantage trees have is that they have evolved with defense as their theme. Their construction, physiology, chemistry, physics and all their other properties and processes have developed with defense as a theme.
Humans have a big brain as their theme and trees have defense.
Defense is a dynamic survival process Strong defense depends on a high amount of energy reserves. When enrgy reserves are low, defense is low. Defense is chemistry. The cell theory is about cells as the basic unit of life. All multi-cellular organisms are made up of cells, which are, in a sense, bags of chemicals and chemical reactions.