An ordinance to amend the 1982 Atlanta Zoning Ordinance to modify sections related to granting variances. Specifically, it amends Section 16-26.003, 'Conditions of granting a variance,' to include new exceptions for the preservation of mature trees. It also creates a new Section 16-26.008, 'Administrative zoning setback variances for the preservation of mature trees,' allowing the Department of City Planning to approve administrative variances on single-family or two-family residential lots to reduce side yard setbacks by up to 50% for tree preservation. Additionally, a new Section 16-20.003(f) is added, permitting the Urban Design Commission to grant variances for the preservation of mature trees in Historic or Landmark Districts. These amendments aim to better protect Atlanta's urban forest by allowing flexibility in setback requirements when mature trees (eight inches or more in caliper diameter for board variances, six inches or more for administrative and UDC variances) would otherwise be lost due to construction. The ordinance requires replacement plans for any trees that die despite the variance.