A Wollemi Pine planted in the Trees of Nations in Alex Goudie Native Park was damaged last week.
One of two Wollemi Pines donated to the park by community members and planted by Friends of Drouin's Trees, the tree was found snapped, with only the bare trunk remaining in the ground.
Judy Farmer from Friends of Drouin's Trees said it couldn't be determined whether the damage was caused by an act of vandalism, by wind, or if the damage was accidental.
"The trunk doesn't have a clean break," Ms Farmer said. "(The) break looks like the tree has either been sheared off by wind – but we haven't had a lot of wind - or someone whacked it with a stick and broke it, we just don't know."
"It was broken right up high where the head of the tree just came away from the narrow trunk. There's another Wollemi Pine near it that was donated and planted last year, and it wasn't hurt."
Often called a "dinosaur tree" or a living fossil, the Wollemi Pine is one of the world's oldest and rarest trees. Fossil evidence of the species dates back 91 million years.
Native to a section of the Blue Mountains, the tree was discovered in 1994 and is considered critically endangered. Wollemi Pines cannot be seen in their natural habitat due to conservation efforts.
The Wollemi Pine was donated to the Trees of Nations in Alex Goudie Native Park in 2022 by Jamie Grey, Sarah Holt and their young son Maverick.
"(The tree) was in our family for a while...when it got too big for the pot that it was in and too heavy to move around, we thought we'd donate it to the community," Mr Grey said.
"We thought it would be fantastic for Drouin to have (a Wollemi Pine) with all the other trees of the world. We thought it would live to its full potential down there (at Alex Goudie Native Park)."
Mr Grey said he and his wife Sarah had planned to take a photo of Maverick next to the tree each year on his birthday to capture their growth together.
"By the time the tree would have grown to 30 metres, our son would have been 60-years-old," Mr Grey said.
"I was so annoyed and really disappointed when I saw the damage. If I take Maverick down there and he sees what's happened, it would break his heart."
Ms Farmer said she hoped Baw Baw Shire Council would consider replacing the damaged tree with another Wollemi Pine from a different part of the shire, and consider different fencing to protect young trees.
"As a group, the Friends of Drouin's Trees, we are very happy to support any of those (options)," Ms Farmer said.