When I was here a few months ago, in winter, there were fires burning. What seems to have happened is that this gully had been colonised by self-sown silver birches, which when left unmanaged grow tall and spindly as they compete for light (a few such trees can be seen still standing). From the Forestry Commission's point of view, this weedy growth will have near-zero commercial value - so that the cheapest method of disposal is to burn it on-site.
Uploaded to Geograph by Stefan Czapski on 22 May 2012
Photo © Stefan Czapski, 22 May 2012. Licensed for reuse under this Creative Commons licence