Sculptor Elpida Hadzi-Vasileva sparked controversy when she planted the trees, one normally and one the wrong way up, at Knowle West Health Park in August.

The installation, called Life Cycle and funded by the regional arts lottery programme, was condemned by critics as a waste of money.

And on Wednesday night, vandals damaged the upside-down tree beyond repair.

Annie Beardsley, co-ordinator of The Art of Wellbeing Project which commissioned the piece, said police had been informed about the vandalism.

She said: "I'm disappointed as a lot of work went in to introduce the idea of art and health and the contribution that creativity and imagination could make to health and well-being.

"It's taken a long time to get these ideas accepted by local people. Now there is a strong local core of support for the idea of arts in health.

"This is a very negative action by two or three people which has determined the environment for the whole neighbourhood. It's very sad."

Ms Beardsley said the group was determined to replace the damaged tree, at an estimated cost of �6,000.