Biodiversity and climate change in Western Australia

Our researchers are actively working to develop an understanding of the impacts of climate change, especially the impacts on the potentially 'at risk' species, communities and ecosystems of Western Australia. This understanding provides the basis upon which our management responses to climate change are formulated and undertaken.

• How might climate change affect our biodiversity?
• Why is there uncertainty about the impacts of climate change on our biodiversity?
• What is DEC doing to protect our biodiversity from the impacts of climate change?
• What research is DEC currently undertaking on climate change and biodiversity?
• What are the key research questions on climate change and biodiversity?
• Further resources & contact information

How might climate change affect our biodiversity?

Climate plays a fundamental role in many of the primary processes of natural systems. Climate is a key factor in determining where individual species of plants and animals can live, grow and reproduce.

Changes in climatic factors such as temperature and rainfall may directly affect the distribution, lifecycles, habitat use, physiology and extinction rates of individual species. In turn these changes may modify the structure and composition of certain ecosystems and communities, by altering competition and other interactions between species. In altered ecosystems, invasive species are likely to thrive, whilst rare species may become extinct.

Climate change may also indirectly affect species and ecosystems by altering important factors such as:

• fire frequency and behaviour
• the degree of dryland salinity
• the spread of diseases such as dieback
• water flows in rivers and wetlands
• the level of groundwater
• the frequency of extreme climatic events (floods, hail, tropical cyclones, drought)
• ocean acidity levels

These factors along with existing environmental stressors may greatly reduce the ability of our biodiversity to adapt to climate change naturally.

Visible signs of the impact of climate change on our landscape may include disappearing wetlands, coral death due to coral bleaching and greater coastal erosion. Visible impacts of climate change on our biodiversity may include changes in the flowering times of native plants, changes to the arrival and departure times of some bird species, a movement away from the usual locations by native animals, a decline in karst (cave) ecosystems, a decline in trees (such as wandoo and tuart) due to water stress, a decline in fish species and a greater spread of weeds and pests.

Why is there uncertainty about the impacts of climate change on our biodiversity?

Because ecological systems are very complex and future climate conditions are not easy to predict, it is difficult to confidently project the impacts of climate change on our biodiversity. Modelling climate change impacts on biodiversity requires good information about a large number of factors including the:

• Distribution of species
• Role of climate upon the distribution of species
• Degree to which species can naturally adapt to climate change
• Capacity of species to migrate
• Potential influence of climate change on threatening processes
• Influence of higher atmospheric concentrations of carbon dioxide on plant and animal physiology
• Ecological processes and interactions between species
• Evolutionary history of species and previous responses to natural variations in climate

Much of our current research has only 'scratched the surface' in understanding these factors. While changes to Western Australia's climate have been measured using specialised weather stations, there is currently only one comprehensive ecological monitoring system in the State. This system, FORESTCHECK, has operated since 2001 and is implemented only within the jarrah forest ecosystem. Dedicated ecological monitoring stations are required throughout Western Australia to enable scientists to identify ecological changes and to develop and implement timely responses.

What is DEC doing to protect our biodiversity from the impacts of climate change?

Reducing the causes of climate change:
One way of lowering atmospheric concentrations of greenhouse gases is to protect existing native vegetation and revegetate on a large scale. Vegetation naturally reduces greenhouse gases by absorbing carbon dioxide. Protecting and increasing existing vegetation are already important components of DEC's land management and nature conservation activities.

Increasing our understanding of the impacts of climate and climate change on WA biodiversity:
To manage climate change scientists need to know the extent to which climate determines where a species is found; and whether climate change will favour rare or vulnerable plants and animals, or contribute to the stresses and forces that endanger them.

In parts of Western Australia, especially in the south-west, the landscape has experienced repeated climate variations over millions of years. As a result, species indigenous to the region may have very broad tolerances for changed or even extreme climate conditions. However, we have a limited understanding of how such cyclic climate variation has affected climatic dependence of the regions plant and animals. Further research is necessary.

Assisting species to adapt to the impacts of climate change:

In many cases, humans may need to intervene to help natural systems to adapt to the impacts of climate change. These interventions include:

• Protecting or establishing habitat corridors:
  Corridors allow plants and animals to migrate through the landscape as climate changes alters environmental conditions and habitats.
• Protecting existing, and identifying new, refuges:
  Refuges are areas that provide natural sanctuaries for plants and animals. Refuges can protect small populations, geographically restricted populations or remnant populations. Populations that occur in past climatic refuges will also harbour increased genetic diversity that may allow adaptation to future climatic conditions. Identifying the characteristics of future refuges is an important activity as it influences the design of the State's national parks and conservation reserves
• Building resilience to climate change:
  One way to protect species and ecosystems from the impacts of climate change is to reduce the effect of existing threatening processes, particularly those that may be exacerbated by climate change. To improve ecosystem resilience DEC actively works to manage and reduce these pressures.
• Safeguarding the most vulnerable species:
  Vulnerable species are those with long generation times, low mobility, highly specific host relationships, small or isolated areas in which they can live and/or low genetic variation. Where climate change is likely to result in such species becoming locally extinct, seed collection and storage or protection in a garden or zoo will be required. Protecting species in this way is an essential element of a comprehensive biodiversity conservation program, and will be an increasingly important option as climate change proceeds in this century.

What research is DEC currently undertaking on climate change and biodiversity?

The Science Division of DEC includes climate change research as a component of many of its biodiversity conservation projects and activities. Our climate change research activities are managed by the Biodiversity and Climate Change Unit (BCCU). The BCCU includes research scientists from all Science Division programs. It includes strengths in ecology, modelling, surveys, phytogeography (geographic distribution of plant species) and genetics, fire science, disease science, and taxonomy.

Science Division's major climate change and biodiversity research projects include:

• Collaborative research on climate change and biodiversity in megadiverse ecosystems
  
  
• Predicting the impacts of climate change on biodiversity and ecosystem function in biodiverse shrublands
  
  
• Temperature thresholds for recruitment in south-west Western Australian flora
  
  
• Assessing the combined effects of climate change and land transformation on the
  geographic ranges of keystone and iconic species in south-west Western Australia
  
  
• Protecting the safe havens: will granite outcrop environments serve as refuges for flora
  threatened by anthropogenic climate change?

What are the key research questions on climate change and biodiversity?

• What are the most appropriate species, and ecosystem indicators for climate change, and how should these be best monitored?
• How will climate change directly affect biodiversity because of temperature and water availability thresholds and increasing atmospheric carbon dioxide concentrations?
• How will climate change affect existing pressures such as fire, hydrological regimes and introduced invasive species, and how will these changes affect biodiversity?
• Will climate change result in new pressures such as new invasive species or land clearing demands and how could these new pressures affect biodiversity?
• What role could contraction to refugia play in maintaining Western Australia’s biodiversity? What are the important refugia to conserve biodiversity in a changing climate, and how should these be appropriately managed and complemented by other management strategies?
• What species will need to and be able to disperse to new locations?
• How can ecological connectivity best be improved and monitored?
• How can Western Australia best invest in translocation?
• What broad ecological and landscape transformation are likely and how can they be managed? How can such areas be restored in a changing climate regime?
• How can Western Australia best invest in ex situ conservation?
• What are the implications of climate change for conservation reserve system design, managing significant ecosystems, such as Ramsar sites and nationally important wetlands, and restoring biodiversity and listed threatened taxa and ecological communities?
• How can land and fire management affect the carbon cycle and greenhouse gas emissions more generally?
• How might climate change impacts on vegetation affect water quality and quantity?

Further resources & contact information

Further Resources: Climate change and biodiversity
Related on this site; staff publications about climate change and biodiversity; websites on climate change and biodiversity.