Vietnam helps Queensland save rare trees

UQ student Le Thach is helping save one of Queensland’s rarest native shrubs along with two of its rare sister species which are also in decline.

Three of the flowering shrubs from the Graptophyllum genus, Holly-leaved Fuchsia, Scarlet Fuchsia and Reticulated Holly are all endangered or rare.

Reticulated Holly is one of the rarest trees in the state with about 1500 trees left on the Sunshine Coast, while Holly-leaved Fuchsia have been grown at South Bank.

The fourth tree, the Queensland Holly, is common around the state.

Mr Thach, a PhD student from the School of Integrative Biology, wants to know why three of these four species are endangered or rare.

He has tested how each tree responds to drought, soil nutrient deficiency and excess light.

He has also been trekking through southern Vietnam forests studying another species, called Dau Cat, which is used for wood, charcoal and for resin used in sealing, waterproofing, paint and varnish.

Mr Thach has been comparing the features of the Queensland shrubs with Dau Cat to help explain species rarity.

His results aren’t finalised yet, but he believes the Queensland trees’ rarity is caused by its photosynthesis processes, growth rate, leaf area and root makeup.

He has ruled out genetic diversity as a cause of rarity.

“Understanding habitat preferences. . . especially the capacity of tolerance to environmental stresses of each species is essential to its ongoing conservation and management,” Mr Thach said.

The Queensland shrubs all grow under five metres tall and bloom with either red or mauve flowers.

Mr Thach said the threats to the Reticulated Holly were urban development, weeds, fire and lack of seeds.

His research results will form part of the Queensland Environmental Protection Agency’s recovery plan for the plant from 2007-2011.

Mr Thach was accompanied in Vietnam by his UQ supervisor Professor Christa Critchley and helped by workers from the Institute of Tropical Biology in Hochiminh City.

His study at UQ was funded by the Vietnamese Government.

MEDIA: Mr Thach (0432 648 180, 3365 2504, s4049237@student.uq.edu.au, Miguel Holland at UQ Communications (3365 2619, m.holland@uq.edu.au)