Australia’s nut trees have been added to the IUCN’s red list of threatened species as numbers in the wild dwindle
When Ian McConachie was growing up in postwar Queensland, his aunt had macadamia nut trees in her back yard. She told him that one day the trees would be famous. More than 70 years later she has been proved right – the Australian nut is a delicacy prized in kitchens around the world.
But this week the macadamia came to the world’s attention for another reason: Macadamia integrifolia, or the Queensland nut tree,was listed as vulnerable on the IUCN red list of threatened species “on account of its population size, suspected at potentially fewer than 1,000 mature individuals”. Its endangered relative, Macadamia ternifolia, has previously been listed on the IUCN red list of threatened plants, as the four macadamia species indigenous to Australia come under significant environmental pressure.
With a history stretching back millions of years, the macadamia evolved on what is now the Australian continent, where the sub-tropical rainforest trees fed Indigenous people for millennia. Their status as an agricultural crop is relatively new, but, says McConachie, a macadamia grower for more than 40 years who is now working to conserve the nut, “macadamias are unique because they are one of very few food plants that domesticated in the last couple of thousand years.”
The nut began its journey to global popularity in the late 1800s, when a handful of seeds were sent from Australia to Hawaii. By the 1920s, the islands had a thriving macadamia industry, says McConachie. The trees that provided the seeds for the Hawaiian industry are still growing, “they’re in the wild near Gympie, near where I live”, he says. In 2019 Gympie, a small town in Queensland, was officially identified as the origin of 70% of the world’s macadamia nuts.