Whanganui District Council tree replacement programme takes staged approach to renewal

"Right tree, right place" is the philosophy Whanganui District Council is using in its replacement programme for street trees and trees in public spaces.

Parks Officer Claire Lilley, an arborist with 20 years' experience, says the current round of tree removals and replacements is part of a 15-year programme.

Eight mature silver birch trees and three saplings were removed from Boydfield St, Whanganui East, last week due to their poor condition and location under powerlines. They will be replaced with amelanchier trees during this winter.

Two mature pine trees will be removed by crane from Queens Park this week because the poor condition of the trees is causing safety concerns. Any replacements will have to be approved as part of the Sarjeant Gallery redevelopment application because of the archaeological significance of the site.

"We have a programme for the next 15 years of selected streets but that will change as priorities change and trees don't perform as we thought they might," Lilley said.

"It's a staged approach to renewal. We try to maintain the character of the suburbs. Sometimes we are planting in streets where they currently don't have any trees at all.

"We tend to do like for like in terms of numbers of trees but powerlines affect the size of trees we plant. If we took out oaks, we probably wouldn't put oaks back in. They're very big trees. Gonville and Castlecliff have sandier soils and tougher conditions so we select for the conditions we are planting in to. It's more the right tree, right place philosophy.

Contractors removed decaying silver birch trees from under powerlines in Boydfield St as part of the tree replacement programme.

"We're taking a lot of birch out. They are difficult for people with breathing difficulties and Whanganui is bad for asthma anyway. We put in medium-sized trees when we replant. Large flowering trees like magnolias tend to be less allergenic."

The street trees are usually inspected every three years but some are checked every year.

"They are well managed and monitored," Lilley said.

"We look for visible defects but you can't always know what's going on with the tree."

Lilley said generally the community understood the need for the tree replacement programme.

"There's definitely a different feel in terms of public support than there was a few years ago. Generally the response is positive and supportive.

"The streets we are choosing to renew have decayed, dying and diseased trees. Often people have been unhappy about having to clean up leaves so they are happy they are gone.

Trees felled in Boydfield Street.

"Generally speaking, it's understood. They can see the reasoning behind it."

Residents in affected streets were contacted by letter to advise them of the tree replacement programme, Lilley said.