Log Production and Processing. - the entire production of logs by all timber licensees shall, beginning January 1, 1976 be processed locally: Provided, That the following conditions must be complied with by whose who apply be allowed to export a portion of their log production to be determined by the Department Head such that the total log export of these timber licensees shall not exceed twenty-five percent (25%) of the total national allowable cut. Provided, further, That no person shall be given a permit to export if he has not complied with the requirements on replanting and reforestation. Provided, That the President may, whenever the export price of logs falls to unreasonably low level or whenever public interest so requires, cancel log exportation or reduce the maximum allowable proportion for log exports.