The tree, which is at least 80-years-old according to National Parks, has been drilled repeatedly and apparently poisoned. Yellowing foliage on the upper branches is the first sign of its inevitable demise.

Over the past 12 months or so, all of the younger plants that grew nearby from its seeds have been poisoned or uprooted. In their place have grown pest grasses and blackberries.

Nearby resident Peter Kestel said he shed tears when he saw the tree had been poisoned.

"It's just disgusting; it's beyond my comprehension, it's a really selfish act," he said.

Mr Kestel remembers sheltering under the tree by the lakeside as a child during hot summer days, and believes generations of people would share those memories.

"In a year it's just going to be another ugly skeleton that's going to create sadness and disharmony.

"People come here for our beautiful environment and have these sorts of images instead."

National Parks area manager Neale Watson said it would

be difficult finding the culprit, as they have to be caught in the act.

But investigations would continue, including a doorknock of the area, and any successful prosecution would result in severe penalties, he said.