Where any fence is to be erected on land covered with standing bush or scrub, and the required notices as hereinbefore provided have been given, the person erecting the fence shall clear the bush and scrub and remove fallen timber for a width of not less than 2 metres on each side along the entire length of the fence, and may fell any tree standing in the immediate line of the fence, and may fell and remove any tree standing on either side of the fence which in the opinion of the said person may be likely to injure the fence; and the cost of such clearing, felling, and removing shall be added to the cost of the erection of the fence, and be apportioned and recoverable accordingly.