Feather-leaved Banksia

Several threatened Banksia species located on the south coast of Western Australia are currently undergoing major decline due to senescence and an associated increase in the occurrence of deleterious aerial canker causing fungi. A lack of fire has allowed these populations to age beyond their prime and become susceptible to disease. Species in the genus Banksia often require fire to release seed from woody cones and promote recruitment and regeneration of a population. We propose to undertake a regeneration burn of a natural population of the Critically Endangered Feather-leaved Banksia (Banksia brownii). Follow up monitoring will then be carried out to assess seedling recruitment, survival and growth rates, and the occurrence of aerial canker in the regenerating community.

A population of the Feather-leaved Banksia is currently undergoing major decline. The area in which the population occurs is long unburnt and largely consists of very old plants that are senescing and becoming vulnerable to attack from aerial cankers. Seed production is declining and although usually held within cones in the canopy until fire causes them to open, dying limbs and plants are now releasing their seed. Despite the seed fall, very few recruits have been recorded and it is assumed that fire is required to provide the appropriate conditions for germination. Therefore, if left to continue upon its current trajectory, the population will become extinct. This project involves undertaking a regeneration burn, monitoring recruitment, seedlings and monitoring the occurrence of aerial cankers within the regenerating community.

In association with this, the biology and fire response of the threatened Trioza barrettae, a host specific plant louse, will be investigated. The louse only occurs on Feather-leaved Banksia and population numbers decrease with increasing plant age. Prior to the fire, a proportion of the louse population will be translocated to safe site and returned upon establishment of new seedlings to ensure the plant louse population survives the fire. Population survival and growth will be monitored.