Dean Baigent-Mercer fears the northern rata’s summer display may be their last.

A dust-like seed softly lands in the top branches of a huge totara. As it germinates the seed sends up a tiny shoot. Over time, the first cotton thread-thin roots become thick like rope and snake down towards the ground. Year by year they swell. This is northern rata, cousin of pohutukawa, growing out the top of its host tree, blocking out more sunlight.

Over centuries the roots strap themselves around their host and fuse to become substantial trunks. The original tree gradually has more shade thrown across it and light is lost for photosynthesis. Its life ends to become compost that feeds the northern rata to grow as a free-standing tree. The twisted trunks are nature's sculptural masterpieces.

Ancient rata giants used to tower alongside rimu over much of Aotearoa. Together they dominated the rainforest skyline.

This summer is the first in a decade where northern rata have flowered extremely hard. Some trees were so comprehensively red you would swear all leaves were gone and only flowers remained. The powerful colour is even more incredible because rata have fine eyelash-like petals.

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Full flowering built up as buds burst open and for each tree only lasted a few days then swiftly diminished. As the flowering ended, the red petals fell to carpet the forest floor. It's an enchanting and rare experience.

The flowers are pollinated by bats, kaka, geckos, bellbirds, tui, hihi and all sorts of bugs by day and night. Fertilised flowers quickly develop seed. Wind shakes and scatters the seed from little capsules. But if the seed doesn't find a place to germinate within weeks, it dies.

The twisted trunks of northern rata are nature's sculptural masterpieces. Photo / Tim Park
The twisted trunks of northern rata are nature's sculptural masterpieces. Photo / Tim Park

Areas under high quality pest control that have had possum numbers kept as close to zero as possible for many years had the best flowering by far. I was gobsmacked by prominent walls of red at Pukaha/Mount Bruce in the Wairarapa and across Kahurangi National Park.

Beautiful Waitakere Ranges northern rata are easiest to see from Scenic Drive between the Arataki Visitor Centre and the turn off to Piha.

Then it dawned on me: this massive mast flowering could be their last.

Why? Because we don't yet know how rata will be impacted by myrtle rust. DoC, hapu and some local authorities are frantically organising collection of seed of rata and pohutukawa species from every region for seed banking. It's a race against an unknown future.

Standing northern rata giants have survived fires, axe and saw. Possums have eaten northern rata to extinction from whole forests and areas. In these places all that remains are lonely disintegrating trunks with no rata offspring to follow them. One day the trunks will be gone and people won't even know they were there.

Even without the new threat of myrtle rust, northern rata are entirely reliant on us for their survival because they are a favourite food of possums. Research shows possum-wrecked native rainforests take 20 years to recover with high-quality pest control that targets all the culprits. Pest control helps build the natural resilience of the bush for the challenges ahead.

This is the summer to collect wild northern rata seed to grow and plant as many as you can. The seed will soon be ready. Good luck!

Lowdown

Beautiful northern rata are easiest to see from Scenic Drive in the Waitakere Ranges in Auckland between the Arataki Visitor Centre and the turn-off to Piha.