The climate at the time was warmer than today, and much of today's moorland was covered with trees. The prehistoric settlers began clearing the forest, and established the first farming communities. Fire was the main method of clearing land, creating pasture and swidden types of fire-fallow farmland. Areas less suited for farming tended to be burned for livestock grazing. Over the centuries these Neolithic practices greatly expanded the upland moors, and contributed to the acidification of the soil and the accumulation of peat and bogs.