5 October 2020
Stretching up past Newcastle and toward the south east of Queensland, the World-Heritage listed Gondwana Rainforests of Australia teem with rich rainforest communities. These include many plants and wildlife endemic to Australia, some with ancient origins in Gondwana, and others listed as threatened species.
The impacts of climate change are already being experienced in the Gondwana Rainforests. Many plant and animal communities, for example, are now restricted to the escarpment and east coast. The 2019/20 Australian summer also saw unprecedented bushfires conditions across much of the Gondwana rainforests, compounded by drought, high temperatures and low humidity.
Critically, there is a current lack of scientific data about future climate conditions, including rainfall and cloud cover in this region. This is hampering the ability of Rainforest Managers to plan and respond to current and future climate impacts.
Co-produced climate data
To produce the assessment, the Hub worked directly with the Gondwana Rainforests World Heritage Area managers. This co-production approach allowed the Hub to meet the challenge of a lack of data head-on. It enabled researchers and managers to understand the factors that needed to be taken into account for assessing climate change risk – and develop the relevant climate change adaption planning questions.
Co-production and knowledge exchange has been an increasing focus for the Hub. Using this approach, the Hub has found that climate change science is more readily accessed, understood and applied to business and operational activities by Australian industries, businesses and governments.
Filling critical gaps in knowledge
As a high-elevation rainforest, the Gondwana property receives up to 40% of its annual water requirement from clouds and fog. This means that resident forest species primarily rely on precipitation received directly from clouds rather than from rain. This is especially the case for some canopy-dwelling species.
The Earth Systems and Climate Change Hub undertook an assessment to examine the effect of changes in temperature, rainfall and relative humidity on both the high-elevation forests and the key species that live there. This research identified a gap in producing projections of future cloud base height (lifting condensation level) the ESCC Hub scientists developed a method to provide a projection of how LCL will effect cloud height in the future which can inform climate vulnerability assessments in environments that are reliant on moisture from cloud cover.
Impacts of a changing climate
Projections were used to analyse the potential climate impacts on the biodiversity of the Gondwana Rainforests.
By 2030, the Gondwana Rainforests can expect:
- An increase in temperature and a slight decrease or little change in relative humidity. Rainfall changes are unclear.
- A rise or little change in the elevation of cloud base, known as lifting condensation level (LCL), used as a proxy for cloud base height.
These projections were consistent up until 2050.
By 2070, projections start to diverge, where Gondwana Rainforests can expect:
- A continued increase in temperatures.
- An overall decrease in relative humidity. Rainfall projections are unclear.
- A range of change in LCL, with moderate increases expected.
Implications of the projections
Initial findings suggest that even moderate increases in LCL may have significant implications for cloud-water dependent species, especially those located at elevations adjacent to the current cloud base.
Reduced cloud water inputs, especially during the dry season, may increase moisture stress beyond the tolerance of some species resulting in community change.
How this information will be used
This information will be used to inform risk assessments for the conservation management of the World Heritage values for the property.
The development of downscaled climate projections and their analysis in combination with ecological and other data can support improved risk assessment, climate adaptation planning and management of the Gondwana Rainforests of Australia World Heritage Area.
The projections resulting from this study can inform future risk assessments for the Gondwana Rainforests, including for bushfire, complementing other spatial tools used by land management agencies to assess and mitigate risk.
The full report from this assessment is available at the following link.
Watch the October 2020 science webinar on this case study.
For more information on the ESCC Hub’s work in Gondwana Rainforests of Australia World Heritage Area, please contact Hub Knowledge Broker, Mandy Hopkins on 03 9239 4649 or mandy.hopkins@csiro.au.