For example, there are very few reported cases of people dying from being planted too deeply, girdled by weed eaters or having their roots driven over. Come to think of it, there aren t many reports of people having roots. As far as I m concerned they do, although it works differently than ours. Trees do not fight an infection so much as they contain it, or seal it off, within their tissues. They also do not replace weakened or damaged cells, but rather grow healthy ones over them.
Trees have both protective processes and protective organs.
Like humans, trees first defense against environmental insults is their skin, or bark. Since a tree can t avoid unpleasant encounters like we can, it needs thick skin. Numerous layers of living and non- living tissue protect trunk, roots and branches from mechanical injury, and the effects of sun and wind. As we know, injuries which tear through bark are common. Animals, accidents and human activity constantly breach this first line of defense.