Years and years ago I was in Jasper National Park in Canada. I was looking at the thousands of acres of timber spreading up the mountainsides to the tree line. It suddenly occurred to me as I lay there that I was seeing was what much of Scotland used to look like. Once the Highlands and much of the lowlands was forest. The Caledonian Forest. All those grand Highland stark mountain views are due to a man-made desert. Those majestic slopes were clad in trees in much the same way as the mountains around Jasper still are. The culprit in the Highlands is humanity via the agency of sheep and deer. The original blanket of trees was burned or cut down for reasons ranging from flushing out outlaws, to making charcoal for early metal smelting, through to boring out tree trunks to make London sewer pipes. But the regenerative new growth never came because the saplings were chewed down by sheep put on the land for profit or deer put there for rich men's sport. Of course, regimented blocks of trees are planted and harvested in Scotland every year but it's not quite the same. And the bio-diversity on the slopes is pretty minimal. Sadly, the damage is too far gone for simply removing the sheep and deer to make much difference - too much soil erosion now for a start.