Potential climate change impacts on forestry in NSW
With temperature and rainfall predicted to change, the potential impacts on forests and forestry are wide and varied:
- increasing carbon dioxide (CO2) concentrations
- increasing temperatures and reduced rainfall
- pest incidence.
Increasing carbon dioxide (CO2) concentrations
General plant research already tells us that increasing CO2 concentrations should result in increasing plant growth, provided the trees are not water-limited. For the impact of increasing CO2 on the forestry industry, however, little research exists that can predict the impacts on whole forest ecosystems, and it is the whole forest ecosystem that allows continued production of trees in a forest.
There are many other factors which will influence the effect of increasing carbon dioxide concentrations on forest growth. These include pests, weeds, competition for resources, soil water and air quality.1
Research - the forest eucalypt experiment
The tree chambers being used in the forest eucalypt experiment
A forest eucalypt experiment is being undertaken in Sydney. It involves using tree chambers to examine the response of major eucalypt species to expected conditions in the future. The chambers can control the conditions in which the tree grows. Specifically the project sets CO2 levels higher than would be experienced today, to see the tree responses that could be expected in future. The project adds an additional stressor of reduced water access to see how these trees respond.
Read more about the forest eucalypt experiment.
Increasing temperatures and reduced rainfall
Hazard reduction burning
Increasing temperatures as predicted by CSIRO of between 0.4 and 2.0°C by 2030 will very likely mean that the number of very high and extreme fire danger days could increase by as much as 25% by 2020, and 70% by 2050.2 This poses a higher fire incidence risk to NSW forests, and a reduced time period over which hazard reduction burn activities could occur. Hazard reduction burning is an effective forest management tool as it helps to protect native forests and plantations from the threat of severe bushfires during warmer drier months.
Download map showing forest types in a part of Nerong State Forest as at April 2008, Central Region, NSW (131kb PDF)
Plant species distribution changes
Changes in the distributions of flora are likely to occur to some extent over time, as physical tolerances of plant species may prohibit them from occupying a place with less rainfall or more intense temperatures. See map of forest types in part of Nerong State Forest as at April 2008 (131kb PDF).
Pest incidence
Climate change is likely to affect the incidence and severity of pest and disease outbreaks in native forests and plantations.3 Changing weather patterns and shifting maximum and minimum temperatures could have the potential to extend the geographic distribution of pests and pathogens, affecting forest communities not previously at risk.4 For example, plant diseases or harmful insect distributions that are currently restricted to Queensland or Victoria due to temperature or rainfall limitations could become a problem for NSW forests in the future.
Mature fruit and leaves of Blakely's red gum (Eucalyptus blakelyi) showing damage caused by psyllids ('lerps').
- Invertebrates can cause damage to the forest. Invertebrate pests include insects such as leaf chewing beetles, sawflies, leaf skeletonising moth larvae and sap-sucking psyllids. For example, in pine plantations, the pine-killing wood wasp (Sinex noctilio), the Monterey pine aphid (Essigella californica) and the five-spined bark beetle (Ips grandicollis) all have the potential to reduce commercial productivity. Find out more about insect pests of exotic pine plantations.
- Pathogens include diseases, fungal infestations and nematodes (microscopic worms). Pathogens have the potential to cause decreases in forest productivity. For example, the fungus Quambalaria pitereka affects spotted gum in NSW. Shoot blight and tip death occurs, resulting in loss of growth and tree death in severe cases.
Further information
For more information on forest pests and diseases, the Australian State of the Forests report contains more information about the impacts of pests species on Australian forests and can be found at the Forests Australia website at adl.brs.gov.au/forestsaustralia/
Return to Climate change and forestry.
1Korner et al. 2005; Ainsworth & Long 2005; Tubiello & Ewert 2002; Karonsky 2003; Fuhrer 2003, In: H Fairweather & A Cowie, Climate change research priorities for NSW primary industries, NSW Department of Primary Industries, Orange NSW, 2007.
2NSW Fire Brigade, 'Climate change creating major challenges for fire services', www.nswfb.nsw.gov.au/page.php?id=779
3H Fairweather & A Cowie, Climate change research priorities for NSW primary industries, NSW Department of Primary Industries, Orange NSW, 2007.
4RJC Cannon, 'The implications of predicted climate change for insect pests in the UK, with emphasis on non-indigenous species', Global Change Biology, vol. 4, pp. 78596, 1998. In: H Fairweather & A Cowie, Climate change research priorities for NSW primary industries, NSW Department of Primary Industries, Orange NSW, 2007.