Introduction to STRATUM Model and Application

What makes STRATUM different? Street trees, not entire urban forest Costs, not only benefits Management tool, not only for advocacy Tree inventory-based, not GIS Answers the question: do the accrued benefits of street trees outweigh the cost of their management?

Structure Function Value Management Needs

The Foundation: Reference City Research Regional Tree Guide studies to develop growth models of representative street trees and their dimensions as a basis for Benefit-Cost Analysis.

Reference City Research Collected local street tree data Analyzed growth rates and dimensions Estimated magnitude of annual benefits Priced benefits Priced tree care costs Calculated net annual benefits, benefit-cost ratios

Tree Size, Growth, and Functionality

Sweetgum in three climate zones at age 40 Inland Empire Coastal S. CA Central Valley

Research Process— Benefits Heating & Cooling Energy - Regional market prices ($0.095/ kWh, $0.97/therm) Carbon trading credits - CO2 ($15/ton) Air Pollutants - Transaction costs, damage value and control cost of emissions ($1-15,000/ton) Stormwater Runoff - Retention/detention costs ($0.005/gal) Residential Property Increase - Average resale price (median sales price = $254,000)

Research Process—Costs Planting Pruning Removal and disposal Pest and disease control Irrigation Infrastructure Leaf litter cleanup Liability Administration

The STRATUM Application

Define Costs   Define City

 Define Benefit Prices

Structure Function Value Management Needs