"Little if any heather moorland in the UK is natural vegetation."

Really Shaw? Who introduced and planted it and when Shaw?

Your perception of "natural climax vegetation" presumes that you start with rock and finish with mature forest which of course is complete and utter bollocks as not all ground is suitable for that to be uniform.

Heather requires acid soil it grows in places that may allow part of the "natural climax vegetation" process to occur but seeds from shrubs and trees cannot survive.

We are talking about the same plant here aren't we "Bio" Steve?

Calluna vulgaris (known as common heather, ling, or simply heather) is the sole species in the genus Calluna in the flowering plant family Ericaceae. It is a low-growing perennial shrub growing to 20 to 50 centimetres (7.9 to 19.7 in) tall, or rarely to 1 metre (39 in) and taller, and is found widely in Europe and Asia Minor on acidic soils in open sunny situations and in moderate shade. It is the dominant plant in most heathland and moorland in Europe, and in some bog vegetation and acidic pine and oak woodland. It is tolerant of grazing and regenerates following occasional burning, and is often managed in nature reserves and grouse moors by sheep or cattle grazing, and also by light burning.

Not natural my foot - another correction for you Shaw to pack away with your flocks of farmed grouse and packs of vicious dogs. I cannot believe that you ever actually qualified to teach anything. Perhaps that is why you moved about so much, so far and so often.