When an order is made by the Tree Officer under section 345, section 346 and section 347 subject to the provisions of section 349, it shall be the duty of owner or occupier of the land who is directed to plant a tree to see that the tree grows properly and is well preserved. It shall also be the duty of such owner or occupier to preserve all other trees existing on the land at the time of commencement of this Act within the area in which the land is situated.