Climate change has been a major focus for Tim Low over the last decade. More than 200,000 words have been produced for such clients as the Australian Government, Queensland Government, Murray Darling Basin Authority and Brisbane City Council.

The two main areas of focus, for which many management recommendations have been provided, have been syntheses of impacts on biodiversity, and interactions with invasive species.

 

Biodiversity impacts

Tim’s most important work to date has been a major report for the Queensland Government, considered further here and provided here. 

Two reports for Brisbane were the first in Australia to assess the vulnerability of local government natural assets, and recommendations from one found their way into the Australian Government’s book, Australia’s Biodiversity and Climate Change.

For Ipswich City Council Tim mapped climatic refugia, presenting management recommendations to key landholders. In the Southern Downs he also addressed landholders about vulnerability.

Tim’s recommendations go well beyond the limited adaptation toolkit that is routinely advocated (increase protected areas, increase connectivity, reduce other stresses). In an  Ecos article he advocated a ‘uniquely Australian perspective on climate change biology to help our adaptation toolkit grow.’

Tim works from several premises including that:

  • The past is highly informative about the future
  • Australia is ecologically unusual. Predictions and management recommendations from the Northern Hemisphere may prove inappropriate. 
  • The distributions of species reflect a variety of influences, not just climate.

Some biologists are focusing on changes observed in recent decades, when the responses of species to natural climate change, over scales ranging from decades to millions of years, provide a larger and potentially more reliable body of information. To generate predictions Tim undertakes extensive analysis of the fossil record, molecular studies, laboratory studies, plant and animal distribution patterns and paleoenvironmental reconstructions.

 

Invasive species & climate change

For the Australian Department of Environment and Heritage, Tim produced one of the world’s first assessments of the impact of climate change on invasive species, one that attracted international interest. It was produced after he ran a workshop on the topic in Canberra.

For the Murray-Darling Basin Authority Tim assessed the potential of climate change to alter the impacts of introduced fish and weeds on Australia's main freshwater system, in a major report.

Another report he co-authored, launched at the Greenhouse 2007 climate change conference, reviewed the potential of new biofuel crops to become invasive. He was also lead author of a journal article about this topic.

 

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arrow-upExtreme climatic events are expected to prove more damaging in the short term than incremental changes. The 2011 floods in eastern Australia had significant impacts. In Climate Change and Queensland Biodiversity, these are recorded as including ‘terrestrial weeds spread by overland flows, aquatic weeds and pest fish carried to new catchments, increased weed germination and growth rates, and feral pig movement into more arid areas.' Floods also provide some benefits for biodiversity by creating ideal conditions for plant recruitment.
Weevil-1
In many climate assessments the direct impact of higher CO2 levels on plants are disregarded or given cursory treatment. CO2 impacts have been analysed by Tim in several reports and in an article he co-wrote for Ecos. Nutrient limitations may minimise a CO2 fertilisation effect in most ecosystems, resulting in plants saving water by reduced stomatal aperture. A different consequence may be reduced nutrient levels in foliage, to the disadvantage of herbivores such as the diamond weevil (Chrysolopus spectabilis).

Industrial CO2 emissions reduce water loss by leaves by increasing the ratio of carbon gained to water lost. Higher CO2 thus has the potential to compensate plants for declining rainfall by increasing water use efficiency.
Spotted Marsh Frog last1
In a project funded by the Queensland’s Low Carbon Diet initiative, Tim produced text for a leaflet for Ipswich City Council and discussed management issues at a meeting with key landholders.

By retaining logs and thick ground cover landholders can assist animals such as the spotted marsh frog (Limnodynastes tasmaniensis) survive hot dry spells.
Crevice Dragon last
The red-barred crevice dragon (Ctenophorus vadnappa) probably faces more risk from droughts than heat waves because it has buffered rock crevices to retreat to when temperatures become extreme. 

Many reptiles have small distributions centred on geological features, showing the role of rock outcrops in conserving lineages through past climate change. A small distribution need not indicate high vulnerability to climate change.