or A&O areas, are parts of the Forest that contain particularly old and impressive trees. 
There are special rules for how the A&O areas are managed.
Some of the trees in the A&O areas are ‘pollards’, which means that their trunks were once cut across at about head height. Pollarding makes lots of new branches grow where the trunk is cut, and also makes the trunk grow very thick.
If you see a pollard oak it must be well over 300 years old, because pollarding oaks in the New Forest was banned in 1698 by Parliament. The New Forest was an important source of wood for building ships for the navy, and pollarding was causing a shortage of long timbers.