sentences:  Much of the arable land is in the south, southeast, southwest, on Anglesey, and along the coast.However, specifying the ancient usage of land is problematic in that there is little surviving evidence on which to base the estimates.Forest clearance has taken place since the Iron Age, and it is not known how the ancient people of Wales determined the best use of the land for their particular circumstances, such as in their preference for wheat, oats, rye or barley depending on rainfall, growing season, temperature and the characteristics of the land on which they lived.