On January 24th 2017, San Diego’s City Council unanimously approved its Urban Forestry Program Five Year Plan to help the city meet its commitment to climate change mitigation and resilience, carbon sequestration, stormwater runoff reduction and water conservation as set out in the city’s Climate Action Plan.
The Climate Resiliency Strategy 5 of the city’s Climate Action Plan establishes the goal of increasing San Diego’s urban tree canopy cover Click & Tweet! , with targets of 15% urban tree canopy cover by 2020 and 35% by 2035.
The benefits of a green skyline
There are many benefits of having a mature urban canopy. For instance, 100 large, mature trees have the potential to:
- Remove 7 tons of carbon dioxide
- Remove 328 pounds of other air pollutants
- Catch around 215,000 gallons of rainwater
In addition, statistics show that tree-filled neighborhoods are safer, more sociable Click & Tweet! and help reduce body and mind stress. Meanwhile, tree-lined business districts enjoy more frequent shoppers Click & Tweet! , longer shopping trips and even a greater willingness from customers to pay more for parking.
San Diego’s strategies for greening the skyline
Because it is not possible to plant enough trees to meet these targets, San Diego has developed a three-pronged strategy involving data collection, technology and partnerships to plant new trees as well as preserve the city’s current trees.
Obtaining an inventory of trees
In 2003, the urban tree cover of the city was estimated to be 7% from sampling aerial imagery at a 30-meter resolution. To increase the accuracy the city conducted in 2015 a remote-sensing study using LiDAR, which found the urban tree canopy to be 13%. To meet the targets of 15% by 2020 and 35% by 2035, the city will increase the data resolution further to identify opportunities to plant new trees as well as strategies to preserve the current canopy.
Leveraging technology to better manage trees
San Diego aims to implement an integrated Enterprise Assessment Management (EAM) solution to manage its infrastructure assets, including trees, at a desired level of service for the lowest lifecycle costs. The EAM solution will enable the city to use information on condition, status and maintenance history to assess and measure lifecycle costs, evaluate the broader costs and benefits of infrastructure projects and develop optimal maintenance and capital investment strategies.
Establishing partnerships to gain citizen support
A key aspect of the city achieving its urban forest targets is to leverage and support current and potential community partners. One key partner is the Community Forestry Advisory Board which provides recommendations related to the city’s urban forest policies and programs and facilitates networking with other boards, agencies and community residents. Overall, community partners can marshal tree-planting volunteers, inform and engage the public on how to plant, care and grow trees within the city as well as provide political support in sustaining public investment in green infrastructure and the urban forest.
For any climate adaptation strategy to be successful, it needs to merge data, technology and stakeholder engagement to ensure targets are achieved.
*Robert C. Brears is the author of Urban Water Security (Wiley)