Sustainability and Energy Action Plan

NATURAL SYSTEMS GRANTS PASS SUSTAINABILITY AND ENERGY ACTION PLAN Project NS -2. Prioritize Tree Disposal Methods With the Greatest Retention of Sequestered Carbon When tree waste is disposed of, the tree can release all the carbon it has been sequestering back into the atmosphere, reducing the efficacy of urban forest carbon sequestration.83 However, some alternative tree waste disposal methods can reduce the extent to which this happens .84 Staff can encourage these methods in the order listed either by directly engaging in that disposal method themselves or by giving preference to contractors who use the methods listed below. NS-2-1. Establish Custom Milling andBiochar as Preferred Tree Disposal Options Prioritize disposal through either custom milling when a tree is of a high enough value to be eligible for such, or through the production of biochar when custom milling is not an option. NS-2-2. Establish Disposal Through Burial/Hügelkultur as Secondary Disposal Options Whether through a contractor or City staff, returning the tree waste to the soil matrix (Hügelkultur) should be seen as a secondary preference before more traditional disposal methods are utilized. NS-2-3. Establish Wood Chipping for Mulch or Composting as the Minimum Standard Disposal Options Tree disposal through wood chipping for mulch or composting should be a minimum standard to avoid landfilling of tree waste. Biochar is a material similar to charcoal produced by heating up tree waste in a special kiln. It is considered a sustainable product that helps decrease the need for fertilizers while also helping to reduce carbon emissions. 77 Hügelkultur is a horticultural technique in which a mound of logs, branches, leaves, and other biomass is covered with soil and used as a garden bed.