Why Halifax is cataloguing up to 30,000 trees on the peninsula

The Halifax Regional Municipality is planning to create an inventory of almost every tree on municipal property in peninsular Halifax.

The municipality issued a tender last week for a company to collect data on each tree's global positioning system (GPS) location, species and trunk diameter.

While the project may seem daunting to industry outsiders, Crispin Wood, the municipality's superintendent of urban forestry, doesn't characterize it that way — quite the opposite, in fact.

"We decided to start small," he said. "This shouldn't be a huge amount of labour."

The inventory will include all trees that were intentionally planted, but will not include trees in naturalized areas. 

Wood estimates there are 20,000 to 30,000 trees on the peninsula that will be eligible for inclusion in the inventory.

The data will be used to improve budget planning for pruning, removal and replanting, as well as to help monitor and prevent the spread of invasive pests such as the emerald ash borer.

The municipality already has an inventory of the trees that have been planted since 2014, which has helped planners figure out which species are successful and which ones aren't.

"Species that once couldn't survive in Halifax now are thriving," Wood said.

"Species that we once planted significant quantities of, we now know are maybe not as conducive to the harsh climates of cities with high pollution and heat island effect and salt intrusion and snowplows and icing events."

For instance, Wood said sugar maples were once planted along the streets, but foresters have realized they don't fare well there.

Conversely, species such as zelkovas, pin oaks and gingkos are thriving in Halifax.

"The climate's changed over the past hundred years.… Twenty-five, 30 years ago, liquid amber would not have been considered a species we would plant here. Today, we do consider it," Wood said.

The database will also be used to help target trees for pruning, which will help prevent storm damage and contact with power lines, Wood said.

Halifax is not alone in tackling a tree inventory. Wood said many larger municipalities in Canada have undertaken similar projects.

The inventory may be expanded to the rest of the municipality's estimated 180,000 trees if the pilot project is proven to be beneficial.

Wood said he hopes to have the data collected by early fall.