Get trees into your State Implementation Plan: 1. Conduct a resource assessment. Assess the current canopy cover in your Air Quality Management District (AQMD). Determine how many potential sites could be successfully planted or regenerated. 2. Develop a range of planting scenarios representing business as usual, and selected future plantings to determine the impact of different species mixes and tree densities on air quality 10 to 40 years in the future. 3. Model the effects of planting scenarios on air quality. Using data in the canopy cover assessment, conduct a modeling analysis to account for the following: • Impacts of air temperature changes on atmospheric chemistry including formation of ozone, other oxidants and particulate matter. • Impacts of deposition (removal of pollutants from the atmosphere) changes on air pollutant concentrations. • Impacts of increased tree cover on biogenic volatile organic compounds (BVOCs) emissions. Emissions of BVOCs are of concern because they are precursors to ozone and particulate matter formation. • Impacts of avoided emissions changes. Avoided emissions may occur because of reduced urban temperatures resulting from increased tree cover. Examples include reduced mobile source emissions and reduced emissions related to power generation for air contitioning.
4. Develop a plan to increase tree canopy cover based on the modeling. Be sure to consider the number to plant, where to plant, species (particularly the high emitters of BVOCs), growth, ultimate size, maintenance requirements, and mortality. For information on tree selec- tion go to: http://selectree.calpoly.edu 5. Consider developing a database to account for new plantings and a change in tree canopy cover. This program evaluation will be required to verify that the estimated increase in canopy is attained. One idea being used in Houston is a web-based system for tracking new plantings. 6. Submit measure within your State Implementation Plan (SIP). Since trees are new to the SIP process, work with your EPA regional office and local AQMD to develop your tree canopy enhancement program.