Bulletin

Issue: October 2006

Research in Action

Tracking our changing vegetation

In 1853, the astute and resourceful Charles La Trobe, Governor of the Colony of Victoria, despatched his newly appointed government botanist, Baron Ferdinand von Mueller, on a long and painstaking assignment.

La trobe university plant
ecologist, dr John Morgan is
assessing vegetation and
climate change on Victoria’s
mountain summits.

Von Mueller was to track through the bush of eastern Victoria to places like Mount Buller and Mount Hotham, climb the mountains, and record the alpine vegetation growing on the summits.

Being a meticulous botanist, von Mueller took six months to undertake the task, collecting 120 specimens at Mt Buller alone, and then pressing their leaves and describing them scientifically before carefully storing them at the Botanic Gardens in South Yarra.

More than a century and a half later, the good Baron’s specimens are helping La Trobe University plant ecologist, Dr John Morgan, to assess how the vegetation and climate on Victoria’s mountain summits has changed since that time.

With colleagues from Macquarie University, the University of Melbourne and the National Herbarium of Victoria, Dr Morgan has received an ARC Network for Earth Systems Science grant to collate 150 years of botanical information on Victorian alpine plants. Some of this data, including that from Baron von Mueller’s time, goes back to 1853.

‘It’s like doing a long-term ecological study over 100 years, except that we are not doing most of the fieldwork,’ says Dr Morgan from La Trobe’s Department of Botany.

‘It’s already done by people like von Mueller, appointed government botanist in 1853 and Director of the Melbourne Botanical Gardens from 1857 to 1873, Dr Jim Willis, a government botanist from the 1940s to the 1970s, and scores of others including amateur botanists, explorers, miners and settlers whose journals and notes, scientific papers, diaries and letters lie in herbariums, libraries and government archives.

‘By collating these very valuable and under-used resources, we can provide a benchmark against which changes in species distribution, or flowering times, can be assessed. ‘Phase one of our project will be to collate this information to develop a picture of what alpine plants grew on which mountains in Victoria more than a century ago.

‘In phase two, we plan to re-visit mountain tops at Mt Buller, Mt Hotham and Mt Bogong to assess which species are still present and which may have disappeared or have changed their flowering times or other characteristics. This in turn provides information about climate change.

‘Mountain tops are important locations to assess impacts of climate change on native species.

‘This is because they represent the thermal limits for many species, and hence are expected to be one of the first places changes in species composition can be detected due to global warming.

‘Because of the short growing season, and with many species dependent on temperature for flowering, shifts in the timing of flowering may also be detected due to increases in global temperature.

‘Importantly, alpine areas are often well-defined locations where confusion is unlikely to occur about the naming of the place. Because they are above the tree line – the thermal limit of growth by trees – they often represent well-defined areas where search effort is likely to have been concentrated.

‘Hence, false absences – failure to detect a species when it is actually present – are likely to be lower than in more timbered or dense vegetation. ‘

While modern botanists extol von Mueller’s botanical expertise and meticulous record keeping, his penchant for disseminating blackberry seeds through the bush, with a view to providing recognisable food for lost European settlers, has left a legacy of a very different type – blackberries now infest some of the remotest regions of the high country.