Ancient woodland
In the United Kingdom, ancient woodland is that which has existed continuously since 1600 in England, Wales and Northern Ireland (or 1750 in Scotland). Planting of woodland was uncommon before those dates, so a wood present in 1600 is likely to have developed naturally. In most ancient woods, the trees and shrubs have been cut down periodically as part of the management cycle. Provided that the area has remained as woodland, the stand is still considered ancient. Since it may have been cut over many times in the past, ancient woodland does not necessarily contain very old trees. For many species of animal and plant, ancient woodland sites provide the sole habitat, and for many others, conditions on these sites are much more suitable than those on other sites. Ancient woodland in the UK, like rainforest in the tropics, is home to rare and threatened species. For these reasons ancient woodland is often described as an irreplaceable resource, or 'critical natural capital'. The analogous term used in the United States, Canada and Australia (for woodlands that do contain very old trees) is "old-growth forest". Ancient woodland is formally defined on maps by Natural England and equivalent bodies. Mapping of ancient