JBM-HH proactive in climate change battle

By DENISE CASKEYMay 12, 2023

A stand of around 40 saplings grow near the Joint Base Myer-Henderson Hall Memorial Chapel on May 5. The trees – a mix of White Fringe, Honey Locust, Eastern Redbud, American Elm, Swamp White Oak, Tulip and Sweetgum – were planted in 2019 by the JBM-HH Directorate of Public Works.
A stand of around 40 saplings grow near the Joint Base Myer-Henderson Hall Memorial Chapel on May 5. The trees – a mix of White Fringe, Honey Locust, Eastern Redbud, American Elm, Swamp White Oak, Tulip and Sweetgum – were planted in 2019 by the JBM-HH Directorate of Public Works. (Photo Credit: Denise Caskey/JBM-HH Public Affairs) VIEW ORIGINAL

JOINT BASE MYER-HENDERSON HALL, VA. – In a bid to proactively tackle climate change and improve the sustainability and resilience of the of the installation, Joint Base Myer-Henderson Hall is working to grow the installation’s tree canopy.

The plan to preserve existing trees and replace every tree that must be removed from the installation with at least two more was adopted more than a decade ago.

“The installation has a sort of base requirement of a replacement ratio of two to one,” said Jenny Tolbert, environmental scientist with the Directorate of Public Works.

However, she pointed out the installation more closely follows the National Capital Planning Commission’s sliding ratio, which uses the size and condition of the tree to determine how many trees are needed to replace the one being removed.

For example, according to the NCPC guidelines from July 2020, if the tree being removed is less than 10 inches in diameter, it would require only one tree to replace it. However, a tree that is 25 inches or more may need six trees planted to replace it – depending on the condition of the tree before it was removed.

Kelly Whitton, the Cultural Resources and National Environmental Protection Agency program manager for DPW, said the installation has planted hundreds of trees under this plan over the years. Results of the plan can be seen near JBM-HH’s Memorial Chapel, where a stand of nearly 40 trees was planted in 2019.

To determine which trees get planted, Whitton said DPW tries to use as many native and noninvasive species as possible. They work with contractors and planning teams to pick trees for each location based on the size the trees will be when they reach full maturity.

“Growth rates vary widely from one tree species to another, whether they are an ornamental type – typically remaining small and best suited for gardens and areas closer to buildings – which can reach full size in a matter of years, or large landscape trees that may take decades to reach their full size,” Whitton said.

Trees are important for more than just shade

Trees can provide some protection from the sun and rain, but Tolbert, a stormwater expert, said having a healthy tree canopy can slow down the rain enough to allow it to infiltrate the soil rather than stir up a bunch of sediment and wash it and other pollutants into the storm drains. The tree’s root system also stabilizes the earth, reducing erosion and preventing pollutants from reaching nearby waterways.

Trees can provide additional water filtration through tree box filtration systems at storm drains, Tolbert said. Plans are in place to install tree box filters in the JBM-HH Commissary parking lot and other places around the installation, beginning in October.

“It looks like a normal curb inlet,” Tolbert said. “We’re going to replace that with a precast concrete vault that is loaded with a specific type of soil filter media. Then, we will plant a tree in the grate.”

Stormwater runoff flows into the system at the curb inlet where it is filtered by the soil filter media. Pollutants are captured and held in the soil filter media, where they decompose and are then taken up by the tree, providing it with helpful nutrients, Tolbert said. Then the treated water is discharged.

A healthy tree canopy also helps with heat reduction by preventing sunlight from reaching the ground below and cooling the air around the trees through the process of evapotranspiration. Plants in general also suck up a lot of carbon dioxide, storing the carbon in a process called carbon sequestration, and releasing oxygen, Tolbert said.

“The Installation’s tree policy and goal of preserving existing trees and increasing the overall tree canopy on base aligns with the Army’s overall sustainability initiative, because of the many positive benefits of trees, including: decreasing erosion and stormwater runoff, lowering ambient temperatures, providing shade for troops and the public, improving air quality and providing habitat for wildlife,” Tolbert said. “These positive impacts increase the sustainability and resilience of JBM-HH’s environment, infrastructure and workforce, in turn preserving and protecting the land that the military relies on to carry out the installation’s missions.”