Repairing Existing Public Lands by Adding Necessary Trees Act or the REPLANT Act This bill directs the Department of Agriculture (USDA) annually for each of the 10 years after enactment of this bill to transmit to Congress an estimate of the sums necessary to be appropriated, in addition to the funds available from other sources, to replant and otherwise treat an acreage equal to the acreage to be cut over that year, plus a sufficient portion of the backlog of lands found to be in need of treatment to eliminate the backlog within the 10-year period. After such 10-year period, USDA shall transmit annually to Congress an estimate of the sums necessary to replant and otherwise treat all lands being cut over and maintain planned timber production on all other forested lands in the National Forest System to prevent the development of a backlog of needed work larger than the needed work at the beginning of the fiscal year. Each reforestation activity included in a renewable resource assessment shall be carried out in accordance with applicable Forest Service management practices and definitions, including those contained in a specified amendment and regulations related to silvicultural practices. The Forest Service shall, based on recommendations from regional foresters, create a priority list of reforestation projects that primarily take place on priority land, promote effective reforestation following unplanned events, and may include activities to ensure adequate and appropriate seed availability. USDA shall give priority to projects on the priority list.