; and (B) establish procedures and timeframes to monitor and revise the harvest levels established for forest botanical products. (2) Prohibition on harvest in excess of sustainable levels The Secretary, acting through the Chief of the Forest Service, may not permit under the program under this section the harvest of forest botanical products on National Forest System lands at levels in excess of sustainable harvest levels, as defined under section 4 of the Multiple-Use Sustained-Yield Act of 1960 ( 16 U.S.C. 531 ). (d) Waiver authority (1) Personal use The Secretary, acting through the Chief of the Forest Service, shall establish a personal use harvest level for each forest botanical product, and the harvest of a forest botanical product below that level by a person for personal use shall not be subject to charges and fees under subsections (a) and (b). (2) Other exceptions The Secretary, acting through the Chief of the Forest Service, may also waive the application of subsection (a) or (b) pursuant to such regulations as the Secretary may prescribe. (e) Deposit and use of funds (1) Deposit Funds collected under the program in accordance with subsections (a) and (b) shall be deposited into a special account in the United States Treasury. (2) Funds available Funds deposited into the special account in accordance with paragraph (1) shall remain available until expended without further appropriation. (3) Authorized uses The funds made available under paragraph (2) shall be expended at units of the National Forest System in proportion to the charges and fees collected at that unit under the program under this section to pay for— (A) the costs of conducting inventories of forest botanical products, determining sustainable levels of harvest, monitoring and assessing the impacts of harvest levels and methods, and for restoration activities, including any necessary revegetation