He said this would create a hazard for people who used the park and played around the tree.
"We never like to remove trees from our parks, especially when they are so large.
"However, the tree is in visible decay and arborists have advised it's not safe at the park."
The conifer would be replaced in the coming weeks by a memorial copper beech tree for the late Queen Elizabeth II, Phillips said.
Copper beeches grow up to eight metres and have strong purplish-brown foliage over summer.
"As Marton Park is a traditional park with many exotic trees, the copper beech was chosen for a number of reasons," Phillips said.
"Considered to be a noble tree, copper beech trees are found in many heritage parks across New Zealand and parks in the United Kingdom."
He said it would be the first copper beech in Marton Park and would be sourced from a local nursery.
"Given the past few weeks' events, we thought this would be a perfect opportunity to remember the life and service of Her Majesty Queen Elizabeth II.
"We will set a date for the planting following our local body elections and invite the community to join us, alongside Ngā Wairiki Ngāti Apa and the Marton RSA."
Phillips said after the tree was planted, a plaque would be installed under the tree to memorialise the legacy of Queen Elizabeth II for future generations.
Workers would now grind down the conifer stump and ready the site for the new tree to be planted, he said.
