Life and Death
In a garden I know, one of a group of four trees has died. It was a willow and had been allowed to grow naturally whilst the others had been coppiced regularly. Why did the unpruned tree die and the others remain vigourous?
We may suppose that the increasing surface compared with the volume of living tissue and increased difficulties of transport with increase of size may play their part in the process of senility and that coppiced trees, assuming the cuts do not bring about fungal infection, will have increased life spans. In the same way a Lavender hedge trimmed anually will long outlive a single specimen left unpruned.
With trees as with other perennials, it is only a small proportion that remains alive, and it is the persistance of the older non-living parts which enable the superficial living parts to remain joined together so that we speak of the entire structure, living and dead as an old tree. In one sense a long established variety of potatoe may also be termed an ancient plant, because the tubers we plant today are the youngest surviving parts of an individual that we can trace back to the day that the variety originated; the material connections having perished and the living parts separated in space.
Actually, the willow died of honey fungus, which is rampant in the garden and has killed a number of large trees. So far the fate has not befallen a hard pruned specimen so perhaps the
reason that pruned plants outlive the unpruned is that regular pruning innoculates against honey fungus with the airborne spores entering the cut living tissue.
Just a thought.