Species description and taxonomy
Of the nine macadamia species, seven are found in Australia in two distinct clades (Johnson and Briggs 1975). The southern clade consists of four subtropical rainforest and wet sclerophyll mid stratum trees, all of which have simple leaves arranged in whorls of three or four or opposite, axillary flowers in brush-like hanging racemes, and rounded fruits with a hard brown inner shell protecting the edible nut.
- Macadamia integrifolia
- Macadamia jansenii
- Macadamia ternifolia
- Macadamia tetraphylla
Current species status
With the exception of Macadamia jansenii, which is listed as 'Endangered' under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and the Queensland Nature Conservation Act 1992 (NC Act), all three other species are listed as 'Vulnerable', including Macadamia tetraphylla in New South Wales where it is listed under the Threatened Species Conservation Act 1995 (TSC Act). In addition, all four species are listed on the International Union for the Conservation of Nature and Natural Resources (IUCN) Red List for Threatened Plants (IUCN 1997).
Habitat and distribution summary
All four species are endemic to rainforest and wet sclerophyll forest communities found within the northeast New South Wales-southeast Queensland coastal region. They are genetically closely related, and except for M. jansenii which is known from a single location 150km north of the closest macadamia population, have overlapping ranges.
Clearing for human population growth and development, fragmentation, altered fire regimes, small population size and weed species are the major processes affecting southern macadamia species. Climate change in the form of variable rainfall and higher temperatures, the potential for genetic pollution from commercial plantations, and a lack of public awareness of wild macadamias are also considered significant threats.
The overall objective of this plan is to protect wild populations of the four nominated species from decline, ensure their long-term viability, and raise awareness of flora conservation issues within the community.
Summary of actions
Key actions required for the recovery of southern macadamias include surveying known macadamia populations, negotiating appropriate agreements with landholders to establish greater long-term security for priority areas on private property, providing land managers with the resources to develop and implement management plans for macadamia conservation, establishing an ex-situ conservation program for Macadamia jansenii, identifying gaps in the current understanding of southern macadamia species ecology and commensurate research priorities for conservation, and liaising with State Agencies, Local Authorities and Regional Bodies in order to incorporate macadamia conservation into their biodiversity conservation and natural resource management strategies. The total estimated cost of implementing recovery actions is $1,091,500.