A point of contact with nature.
Is it desecration to tag a living thing? Is it different from tagging the built environment?
Is it similar to a pictograph, or a petroglyph on a rock face?
Would I feel differently if it was a political message, or a carved declaration of love?
Is tagging just a statement of presence? 
Slowly the eucalypt fights back – shedding yesterday’s skin, making its own new marks.