Vandals have desecrated a little piece of inner suburban bush paradise and those who've created and care for the area are angry.

More than 30 years ago, a small but dedicated group of locals decided to turn an area covered in kikuyu and lantana into a natural native oasis.

"Over the years we've planted thousands of trees which are native to this area," said the long-term coordinator of Blue Divers Bush Care Group, 80-year-old Chris Edmond. "In fact, every tree you can see here, we planted.

"It's now been classified as an endangered swamp oak forest adjacent to Towradgi Creek," Chris said proudly. "It's my baby and people have said this is one of the greatest bush care success stories."

Last Sunday, when the group gathered for their monthly working bee near Cassell Park, they were "shocked and disgusted" by what they found.

A dozen mature trees, a mix of paperbark gum trees and casuarinas had been cut down and left strewn across the 525-square-metre site. Other trees had been ring barked, meaning they're unlikely to survive.

'Why would anyone do this?'

"Over the years we've seen a few acts of vandalism but never anything on this scale," Chris said. "Why would anyone do this?"

Chris believes bike riders who've created a track through a section of the forest are to blame.

"In recent years they've created a number of jumps."

He believes the trees were cut down in an effort to expand the track network, but that appears to have backfired.

Within days of the vandalism being reported to Council, the jumps were removed and new signage erected warning that the act of vandalism is now under investigation with "heavy penalties" for anyone prosecuted.

"Ramps and other built structures are not allowed in this public space," one sign says.

"We will need to demolish any tracks built here to protect the unique environment and make this space safe," the Council sign says.

This is the third tree vandalism attack in Towradgi in the past five years. Previously Council expressed its concern when trees near the cycleway were poisoned. Local schools showed their love for the trees with special pictures and words for Council signage.

Punishment must fit the crime

Chris hopes the perpetrators are caught and the punishment acts as a deterrent and an example to others who might commit a similar crime.

"I don't think these people have a grasp of what the environment is, and the importance of it for all of us," Chris said.

The Blue Divers bush carers are now planning their next tree planting and encourage anyone with a love of nature to join them. They meet on the third Sunday of the month from 10-12 noon and anyone seeking more information should contact Chris on 0429 032 862.