Benefit-Cost Analysis of Modesto’s Municipal Urban Forest

Abstract

This study answers the question: Do the accrued benefits from Modesto’s urban forest justify an annual municipal budget that exceeds $2 million? Results indicate that the benefits residents obtain from Modesto’s 91,179 public trees exceeded management costs by a factor of nearly 2. In fiscal year 1997–1998, Modesto spent $2.6 million for urban forestry ($14.36/resident, $28.77/tree), and 74% of this amount was for mature tree care. Total annual benefits from Modesto’s urban forest were $4.95 million ($27.12/resident, $54.33/tree). Net benefits for FY 1997–1998 were $2,329,900 ($12.76/resident, $25.55/tree). Annual air-pollutant uptake was 154 metric tonnes (3.7 lb/tree), with an implied value of $1.48 million ($16/tree). Aesthetics and other benefits had an estimated value of $1.5 million ($17/tree). Building shade and cooler summer temperatures attributed to street and park trees saved 110,133 MBtu, valued at $870,000 (122 kWh/tree, $10/tree). Smaller benefits resulted from reductions in stormwater runoff (292,000 m 3 or 845 gal/tree, $616,000 or S7/tree) and atmospheric carbon dioxide (13,900 t or 336 lb/tree, $460,000 or $5/tree). Due to the population’s relatively even-aged structure and heavy reliance on mature Modesto ash for benefits, management strategies are needed that may reduce net benefits but increase diversity and stability.