YOUR headline "Greens unveil plan to reforest grouse moors" (The Herald, August 30) concerns me. The word "reforest" is misleading. Certainly at the beginning of the 20th century Scotland had less than five per cent tree cover, but this lack of trees goes back centuries: even a cursory look at the Roy maps of the 1750s shows that in the Highlands most woods disappeared before the advent of sheep farm-ing, sporting estates and industrial exploitation, when roads were absent, when livestock was wintered indoors, large tracts of the mid and high-altitude land was uninhabited and unused, and wolves were still present. All the evidence points to natural rather than anthropogenic decline of woodland in most places, and such decline also occurred in interglacial periods in the absence of humans: we are in what is termed the "oligocratic phase", a natural phase of soil acidification and woodland loss.

I would ask "reforesters" just to stop for a moment and consider whether it is possible that our open upland landscapes are natural in origin, so that covering them with trees will in fact result in a loss of natural habitat, a loss of biodiversity; that "five per cent woodland cover" in fact should be something distinctly Scottish and something to celebrate in that it makes Scotland distinctive on a European scale. After all, it is not the moorland’s fault that people shoot grouse over it.

Additionally, one needs to be careful in assuming that tree planting in our uplands mitigates global warming: trees can dry out organic soils, releasing more carbon from the soil than what would be stored in trees and also preventing the moors to go on to become deep peat with a high carbon storage potential. Trees also significantly reduce albedo (reflectivity of the land) and so warm up the climate.

Be careful what you wish for.

James Fenton, Oban.