British wildwood, or simply the wildwood, is the wholly natural forested landscape that developed across major parts of Prehistoric Britain after the last ice age. It existed as the main climax vegetation in Britain for several millennia as the result of the relatively warm and moist post-glacial climate and had not yet been destroyed or modified by human intervention. From the start of the Neolithic period, this wildwood gradually gave way to open plains and fields as human populations increased and began to significantly shape and exploit the land to their advantage. The wildwood concept has been especially popularized by ecologist and countryside historian Oliver Rackham in his various works