Common trees in the Ancient and Ornamental Woodlands are Beech, and Oak with an undergrowth of holly, crab apple, silver birch, blackthorn and hawthorn. Pine, sweet chestnut, horse chestnut, whitebeam, yew, viburnum, ash and sycamore are also found, with the alder tree forming a classic fringe to the boggy upstream rivers.The Ancient and Ornamental Woodlands boast a large number of spectacular old pollards. Beech and oak are the two pollarded trees in abundance in the New Forest.
"Pollarding", or chopping the tops of trees off at head height to make it easier to gather the branches, has not been practised (legally!) in the Forest since 1698. In that year, King William (of William 'n Mary fame), who was never a great deer hunter, forbade pollarding in order to promote the growth of quality timber in long lengths, for ship building.
In the interests of history, I have shinned up various trees, or bent double to examine felled trunks, to count the rings of several decaying old pollards. To my surprise, the ring-count is often between 200 and 300, indicating that pollarding was still being practised up to 100 years after it become illegal.
My guess is that branches were persuaded to fall off accidentally every few years - the evidence would be gone by morning, and only those who knew the wood intimately (ie the miscreants themselves), would miss the loss of a single bough.