Helena gum moth larva Opodipthera helena
Helena gum moth larva Opodipthera helena
- Photo © J Farr/ Parks and Wildlife

The health of the forest can be affected by:

Lightning strikes mean that fire occurs naturally in the south-west. Fire is important in nature, including the regeneration of native vegetation, seed germination, and the release of nutrients needed for plant growth. Large, intense bushfires, however, can threaten life and property, and changes in fire intensity and frequency can harm biodiversity.

Protecting and maintaining a healthy forest

Healthy ecosystems are more resistant to pressures such as climate change, so maintaining forest ecosystem health and vitality is important.

The Department of Parks and Wildlife does this through a range of measures, including:

  • planning, implementing and reviewing the prescribed burning program
  • maintaining Western Shield, the biggest wildlife conservation program undertaken in Australia. This statewide program aims to control feral predators so native animals can return to their former abundance or be reintroduced to former habitats.
  • maintaining surveillance and recording systems for forest diseases known to have a significant impact on ecosystem health and vitality
  • providing greater protection to trees or groups of trees that show resistance to pests or disease during timber harvesting operations. This will help maintain the health of the areas where these trees occur and provide breeding stock to re-populate affected areas.
  • continuing to regulate the use of heavy vehicles to protect soil during timber harvesting and other disturbance operations
  • prioritising research and management efforts for pests and diseases in line with that used for weeds. This identifies outbreaks of high impact weeds that are still small enough to eradicate or contain, and areas of high conservation value where weed control is likely to have the greatest benefit.
  • a coordinated approach by all land managers, owners and users because most threats to forest health cross property boundaries
  • the rehabilitation of areas of native vegetation cleared during planned disturbance operations, such as mining and extraction of basic raw materials
  • FORESTCHECK long-term monitoring of jarrah forests.
Psyllids Creiis periculosa
Psyllids Creiis periculosa - Photo © J Farr/ Parks and Wildlife

Pests and Diseases in our Forests

Western Australia, together with other states and territories reports on recognised pests and diseases within state managed forests and plantations.

The scale and impact of agents and processes affecting forest health and vitality are reported in Australia's State of the Forests Report by the Australian Government with input from the state.

The meaning of 'pest' varies with the context. What may be seen as a pest in a human, agricultural or plantation perspective may be seen quite differently in a natural ecosystem.

In Western Australia there are a range of insect groups and species which forest managers regard as useful indicators of forest ecosystem health and vitality.

Forest insects in Western Australia are categorised by how they feed:

  • predators
  • parasites
  • detritivores
  • herbivores.

Insects seen as pests in forests are generally herbivores, and include leaf chewers, sap suckers and wood/stem/root feeders.

Periodic fluctuations in population levels can affect a forest ecosystem by reducing the health and vigour of trees, or reducing the food resource for other forest inhabitants such as mammals and birds. However, insects are not generally known to kill trees in Australian forests.

Poster:  pdfCommon insect pests of Western Australia's Southern Jarrah Forests1.21 MB

Insects featured in this forest pest calendar are known to have occasional population outbreaks, or are potential threats to the ecological processes within our forests if their population or impacts exceed tolerable levels within the natural environment.