Unless otherwise authorized in writing by the Director of the Department of Recreation and parks or the Director’s designee, a person may not remove a tree in a public park without first having been issued a written permit to do so by the Department of Recreation and Parks. Within 20 business days of receiving a request for a permit under this section, the Department of Recreation and Parks shall:approve, deny, or request more information regarding the permit; determine whether mitigation under subsection (c) is required; and notify the applicant of the Department of Recreation and Parks’ determination. Any tree removal permitted under this section must be completed by a licensed tree expert in accordance with Title 5, Subtitle 4, Part III {“Tree Experts”} of the State Natural Resources Article. A tree approved by the Department of Recreation and Parks for removal under this section shall be mitigated as provided in this subsection if:the tree measures 8 inches or greater in diameter at breast height; or the tree was deliberately planted and measures 1 inch or greater in diameter. If the Department of Recreation and Parks requires that a tree be mitigated under this section, the mitigation shall be an inch-for-inch replacement, to be measured as follows:for the removed tree, at the diameter at breast height; and for the replacement tree, at the caliper inch. If the Department of Recreation and Parks requires mitigation under this subsection, the permit holder may accomplish the mitigation by:planting replacement trees at the site or sites of the removal, as approved by the Department of Recreation and Parks; or if mitigation inches required under this subsection cannot be replanted at the site or sites of removal, planting trees at another site or sites only as approved by the Department of Recreation and Parks. If a permit holder cannot accomplish mitigation using a method described in paragraph (3) of this subsection, the permit holder shall pay a fee-in-lieu of mitigation to the Director of Finance. The fee-in-lieu of mitigation shall be a standard amount or unit, as approved by the Board of Estimates and updated as necessary. The Department of Recreation and Parks may exempt a tree from the mitigation requirements of this subsection if the Department of Recreation and Parks determines that the tree is:dead; dying; diseased or otherwise infected and contagious; or at high risk of death, disease, or failure, as determined by the Baltimore City Forestry Division of the Department of Recreation and Parks.