Definition: Tree Preservation Order: TPO
"If it appears to a local planning authority that it is expedient in the interests of amenity to make provision for the preservation of trees or woodlands in their area, they may for that purpose make an order with respect to such trees, groups of trees or woodlands as may be specified in the order."
"A tree preservation order may, in particular, make provision [amongst other things] -
(a) for prohibiting (subject to any exemptions for which provisions may be made by the order) the cutting down, topping, lopping, uprooting, wilful damage or wilful destruction of trees except with the consent of the local planning authority, and for enabling that authority to give their consent subject to conditions;
(b) for securing the replanting, in such manner as may be prescribed by or under the order, of any part of a woodland area which is felled in the course of forestry operations permitted by or under the order."