Wild Macadamia Trees Face Habitat Loss in Queensland

Remnant rainforests in south-east Queensland and northern New South Wales host the four native macadamia species. More than 80 % of the original habitat has been cleared, leaving only fragmented patches such as Mary’s Creek, Amamoor and Imbil. The trees are vulnerable to invasive species like cat’s claw, storm damage, and encroaching logging machinery. One species, *Macadamia jansenii*, is so rare that a single bushfire could eradicate it entirely. The other three species are listed as threatened or vulnerable, making the surviving wild trees a critical genetic bank.

The Guardian

Macadamia nuts, once traded by Aboriginal peoples for rum and tobacco, now underpin a multi-billion-dollar global industry cultivated in subtropical regions worldwide. Commercial production began in Hawaii in the 1920s and only took off in Australia in the 1960s, with the first domestic processing plant opening in 1954. Genetic testing indicates that the majority of commercial macadamia orchards trace back to *Macadamia integrifolia*, the ancestral tree of roughly 70 % of cultivated stock.

The Guardian

Russell Bennet, a Kabi Kabi elder and on-ground guide, likens finding an undocumented tree to “finding gold,” highlighting the cultural connection and the urgency of protection.

The Guardian

Cultivated macadamias possess far less genetic diversity than their wild counterparts. Conservationists warn that loss of the wild gene pool would leave commercial crops defenseless against potential root-rot fungi or emerging pests. McConachie’s patented “MCTI” tree has generated about $2 million in royalties, all of which he has donated to the Macadamia Conservation Trust to fund DNA storage and future breeding programs aimed at climate- and disease-resilient nuts.

The Guardian

• “It is the world’s finest nut,” — Ian McConachie

The Guardian

• “Which is pretty much where everyone wants to live,” — Denise Bond, executive director of Wild Macadamia Conservation

The Guardian