"... during this expedition I was to trudge through sand wastes which had been my forest haunts when I had been in Africa thirty years ago. Here one could actually see all the process of degradation, from high forest through the stages of orchard-bush and savannah to drifting sand. When the forest is cleared for farming or other reasons, the debris is sooner or later burned up. Here we were standing on land where the which had been accumulated over thousand of years had been destroyed in a single season."