La Trobe in global plant study

La Trobe in global plant study

03 Feb 2011

La Trobe University botanist John Morgan is a member of a 36-strong global research team that has shot holes in one of the most common theories about how invasive species establish themselves at the expense of native plants.

Plant research The just-published work in the journal of 'Ecology Letters' has significant implications for research into biosecurity.

Dr Morgan's part of the study was carried out in alpine grasslands at Falls Creek in Victoria and was the only Australian field site in the global initiative.

Invasive plants are a serious environmental, economic and social problem. They lead to loss of native biodiversity and damage the functioning of ecosystem, such as the re-cycling of nutrients.  With climate change, gaining knowledge about plant spread and behaviour has become more urgent.

Dr Morgan says predicting the success of invading species has always relied on the assumption that these plants are more abundant in their new settings than they are in their native communities because they behave in a special way.  

An example is the highly invasive weed English Broom which has infested large parts of eastern Australia and New Zealand because it was thought the absence of natural enemies that kept the species in check in Europe, combined with its ability to fix its own nitrogen, gave it competitive advantages over the native species in its new range.

Instead, the global research team's ‘Home and Away’ study of 26 species at 39 locations on four continents found little difference between plant numbers on their introduced and their native ranges.

'We discovered that increases in species abundance are, in fact, unusual,' says Dr Morgan.

'Hence, success of a plant on its native range can probably be used to predict its spread at introduced sites – a criterion which currently is not included in biosecurity screening programs.'

The study was carried out by the Nutrient Network, with funds from the US National Science Foundation's Division of Environmental Biology.

Its aim was to field test one of the most basic assumptions underpinning invasive species modelling – the 'abundance assumption'.

Contact: Email -

● For further details, see website




La Trobe Media Release RSS