Mass planting boosts rare tree numbers by 10 percent
Seed nursery will form “genetic life-raft” for Turner’s kohuhu
A single mass planting has boosted the national population of the rare and endangered Turner’s kohuhu (pittosporum turneri, or tent pole tree) by more than 10 percent. The Forest Lifeforce Restoration (FLR) Trust has planted 5,500 seedlings, propagated from seed collected in May 2009, in specially-constructed predator-proof enclosures at its Pohokura property in inland Hawke’s Bay.
Only 30,000 to 40,000 pittosporum turneri plants are known to exist in New Zealand and the species has a threat status of Nationally Vulnerable. When mature the seedlings will form the country’s first seed nursery for the plant, the first step towards ensuring a national recovery.
“We hope it’ll be a kind of genetic life-raft for this species,” said FLR Trust forest manager Pete Shaw.
The Hawke’s Bay-based Trust has form when it comes to establishing seed nurseries for rare and endangered New Zealand native plants. It runs the largest Kakabeak (clianthus maximus or ngutukākā in te reo) propagation and restoration programme in the country and now has five seed nurseries dedicated to this plant; four in Hawke’s Bay and one in the Bay of Islands. These have produced hundreds of juvenile Kakabeak which staff have started planting on conservation land.
The Trust collected six litres of pittosporum turneri seed pods in May 2009 and paid to have them propagated at the Taupo Native Plant Nursery. They germinated in mid 2010.
Wild pittosporum turneri at Pohokura have been suppressed in their juvenile foliage stage as a result of possum predation. Aerial drops of 1080 poison in 2008 reduced the possum population and enabled the plants to flower for the first time in decades. The number of seeding plants recorded leapt from fewer than five in 2008 to more than 90 in 2012.
The special enclosures will protect the plants from possum and from the deer, hare and rabbits that would be attracted to the young, fertiliser-laden nursery plants. They will allow seed to be produced and germinated in quantity and have effectively created a new site for the species as previously only a single plant was known to exist in that part of Pohokura.
“This project demonstrates clearly the highly inter-connected nature of the thing that conservation in New Zealand has become," said FLR Trust Chairman Simon Hall. "It can no longer be purely the preserve of government agencies. The job’s too big, the battle’s too fierce. Landowners and the private sector all have a role to play.”
In addition to its work with pittosporum turneri and Kakabeak 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. It is also involved with the re-establishment of native plants and forest on 4,000 hectares currently, or until recently, under pine.