Pohutukawa under threat on coast

For immediate release: Wednesday 17 December 2003 Browsing possums are seriously damaging some of the Bay of Plenty’s coastal pohutukawa and strong measures are needed to protect them, says Environment Bay of Plenty.

Coastal pohutukawa are under threat from browsing possums.

An aerial survey has highlighted possums as a major threat to the health of New Zealand’s iconic Christmas tree in certain areas, including north of Tauranga Harbour and around the East Cape. The region has already lost large tracts of its original indigenous forest and “we cannot afford to lose any more”, says Ian Noble, chairman of the council’s regulation and monitoring committee. “

Mr Noble says serious steps must be taken to protect pohutukawa and other coastal indigenous tree species. “This is a precious resource. We need to put in place a strong management regime which will include intensive pest animal and plant control,” he says.

Environment Bay of Plenty is setting up a programme to monitor the region’s coastal indigenous forests. Last year, it introduced a similar module for wetlands. At the moment, staff are mapping the extent of the trees and checking their health, initially by studying the condition of the canopy from the air.

Environmental scientist Joh Taylor says the work will help staff track changes over time. It will also help Environment Bay of Plenty understand the reasons for the poor health of the coastal forests so they can be managed better.

Ms Taylor says the largest stands of pohutukawa can be found east of Opotiki, near Whakatane, at Matata and north of Waihi Beach. Other remnants tend to be small and fragmented, she explains.

But, whether large or small, they are all highly valued. “They provide important ecological habitat, are a characteristic feature of the coast and also a significant landscape feature.”

A previous survey of the region’s coastline was carried out in 1988 with a segment of the eastern Bay of Plenty (from Otamarakau to Waiotahe) surveyed again between 1989 and 1991.

Coastal forest is vulnerable to a range of threats, including browsing by introduced pests like possums, and also ongoing clearance and grazing by domestic stock. Possums tend to browse heavily on selected trees, removing leaf shoots and opening up the canopy. Ms Taylor says heavy browsing can actually kill trees, even large mature specimens.

Other causes of canopy die-back or ill-health in coastal indigenous tree species include fire, salt spray, wind damage, local insect attack, roads and roosting by shag colonies.

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