DNA tests raise hope for elusive native plant
Spectacular Kakabeak still teeters on the edge of extinction
DNA tests on extremely rare plants discovered in inland Hawke’s Bay offer some hope that the species may yet be saved from extinction. Until recently, just 110 Kakabeak plants (Clianthus maximus, or ngutukākā in te reo) were known to exist in the wild but the tests suggest there is greater potential than previously thought for the species to re-establish itself.
Results revealed slight genetic differences between plants discovered in Te Urewera National Park and nearby native forests, suggesting that the population there has crashed to low numbers only relatively recently.
Imported fauna have impacted wild populations of Kakabeak severely and the species now holds New Zealand’s highest possible threatened plant ranking: ‘Nationally Critical’. Although grown widely in gardens, domestic Kakabeak have limited genetic variation and therefore little genetic value.
Testing was conducted by Dr Gary Houliston, a plant geneticist at Landcare Research, on clippings taken by the Forest Lifeforce Restoration (FLR) Trust from six plants discovered on the Waiau Bluffs in Te Urewera National Park and in nearby native forests over the past two years. Their DNA profiles were compared with the genetic make-up of all wild Kakabeak tested to date, with the results revealing slight genetic differences to others tested in Hawke's Bay.
“The genetic diversity of any plant population is a good indicator of that population’s strength,” said FLR Trust forest manager Pete Shaw. “The fact that these plants were out there highlights the value of continued field searching.”
Dr Houliston said the plants discovered by the Trust were a valuable find for restoration purposes.
One of the genetically diverse plants, Rachel’s Plant, was discovered by Shaw while Trust patron Rachel Hunter was visiting its property in the Maungataniwha Native Forest. This plant has subsequently produced a lot of seed, some of which has been used in the Trust’s Kakabeak propagation effort.
“Potentially, this will make for a much more robust lot of plants in our Kakabeak orchards,” Shaw said. “With any luck these plants will themselves produce good crops of robust and genetically diverse seed, which we can use to re-establish a viable population of Kakabeak in the wild.”
The FLR Trust has already established three Kakabeak seed orchards in protected enclosures at its property in the Maungataniwha Native Forest. Staff are in the process of perfecting a groundbreaking technique to propagate the plants by blasting seeds from a shotgun into likely nursery sites in the wild.
Staffer Barry Crene developed the technique using re-loaded shotgun shells packed with regular shotgun pellets, a pulp medium and Kakabeak seed. The shells were then discharged into soil from a range of 20 metres, about the distance a helicopter might have to hover from likely nursery sites in the wild.
As with the Waiau Bluffs, such sites are frequently patches of topsoil on bluffs or cliff faces that are as inaccessible to humans as they are to browsers. Helicopters are often the only way to reach them.
This innovation will create the potential for an aerial propagation effort on a scale that hasn’t yet been possible.
As well as its work on Kakabeak propagation, the FLR Trust is fast carving out a name for itself with the Maungataniwha Kiwi Project, one of the most prolific and successful kiwi conservation initiatives in the country, and the re-establishment of native plants and forest on 4,000 hectares currently, or until recently, under pine.