Pōhutukawa are being routinely poisoned and "butchered" illegally in New Plymouth, and suspicion is falling on homeowners wanting to enhance sea views.
About six trees have recently been attacked alongside the Coastal Walkway at East End Beach.
New Plymouth Parks and Open Spaces manager Stuart Robertson said the trees were on public land and those responsible had acted incredibly selfishly.
"Someone has used a handsaw and butchered the pōhutukawa at East End Beach, cutting off several metres of branches and leaving them on the ground," Mr Robertson said.
"They're probably trying to improve their view of the sea but what they've done instead is encourage the tree to bush out, be an even bigger visual nuisance and harder to maintain.
"By leaving the trees alone, they grow up and our arborists will trim them properly so that eventually people can see through the tree trunks to the sea."
Mr Robertson said a mature pōhutukawa in Findlay Street in Moturoa had been drilled into and poisoned and would need to be removed.
The vandalism, which had been sporadic over the past five years, was upsetting to parks staff, he said
"It's just sad that people do that to these trees. Some of these trees are actually decades old and you can't replace like with like."
Mr Robertson said most of the affected trees were out in the open and he asked that anyone seen behaving suspiciously around the trees should contact the council or police.
Sea views boost property values - real estate agent
The owner of New Plymouth real estate agents Remax, Garry Malcom, warned against pointing the blame for the attacks on any specific homeowners.
Mr Malcolm said many different people had beef about pōhutukawa.
"Pōhutukawa trees are notorious for having branches blowing down in strong winds and they do cause some issues with blocked drains etc so it could be anybody."
Mr Malcolm conceded, however, that an uninterrupted view of the sea could boost a property's value.
"It's a very personal thing, certainly it does add value. Sea views have become the vogue and there is a demand for those and in my personal opinion they could be worth anything between $50,000 and $100,000 more."