Wendy Ambury with flowering wild ginger on the roadside leading in to Ngunguru. Photo / Malcolm Pullman
Invasive wilding pines are a growing problem in Northland. Wendy Ambury, who is contracted by Northland Regional Council to identify and scope priority sites infested with wilding pines on the Ngunguru Coast, says pine cones have a bigger natural spread than most people realise.
Pollen from a mature pinecan be blown by wind several kilometers and cones can tumble down hillsides and float into waterways. Each scale of a female cone can become a tree.
Northland's mild climate means they are able to grow all year round and are beginning to self-seed and spread at an ever-increasing rate.
"Anyone living along a river or stream will see how quickly wilding pines can become a problem,'' Ambury said.
When planted in the right place, pines provide timber, store carbon and can provide stock shelter. However, left to grow in the wrong place they can become a real problem. Pines change the acidity of the soil to the detriment of native species, and can end up being dominant, taking over the canopy in vulnerable habitats.
A lot of Ambury's time in tackling the wilding pine problem in the Tutukaka/Ngunguru area has been trying to find the mature source trees as every year another crop of cones is produced.
Ambury said many of the source trees were old trees left behind from forestry harvesting, often because they have grown in places too steep to harvest safely, or were remnant trees on private land from early settlers.
"I try to approach the problem with sensitivity and develop good relations with landowners in identifying which trees can be removed.''
Ambury's work is part of a wider project being undertaken by the regional council, funded through the Ministry for Primary Industries (MPI), to carry out wilding pine control in the region. This initiative is aimed at keeping wilding pines away from high-value sites such as coastal margins, dune systems, dune lakes, reserves, geothermal areas, gumlands and regenerating native bush.
"This is also a community problem and requires a community response. Landowners need to get on board and help too,'' Ambury said.
As well as the wilding pine initiative, Ambury is heavily involved in the Tutukaka Landcare Coalition, and runs SWAT, the 'Specialist Weed Assistance Team'. With the support of the regional council, this group is working hard to raise awareness about local weed issues such as wilding pines and helping landowners with advice and avenues for further funding and support.
"Our overall goal is to remove the barriers that prevent people from taking action on the weeds that are invading our properties and reserves, and working across the landscape to stop the spread.''
Out of the hundreds of pest plants growing in the area, the Tutukaka Landcare Coalition has decided to target a 'Dirty Dozen'. The list includes wilding pines, tree privet, Japanese honeysuckle, Queen of the night, English ivy, cape ivy, sweet pea shrub, climbing asparagus, woolly nightshade or tobacco plant, cotoneaster, moth plant, and wild ginger.
"All of these weeds have the ability to really damage our natural landscape. Some, like pine trees and tree privet, produce a lot of pollen that causes allergy problems in some people. Others have sap that is quite toxic or the leaves have little hairs that become airborne and cause skin irritations.
"You really do need to know how to approach each plant, both from a safety perspective and for the best results," she said.
Ambury advises landowners on a work plan and helps with tools to do the job.
The group also runs volunteer events at sites that need extra knockdown help.
"We've got a wonderful group of volunteers in SWAT and we try to make events a lot of fun. Events are created that help people know what they are in for. We've got a group of Ginger Ninjas, some hard core 'missions' and lighter 'weed rambles'," she said.
Given Northland's subtropical climate and prime growing conditions for all plants, weed control work is a massive challenge. However, Ambury said, there was a lot of satisfaction from going back to view the results.
"It is amazing what can be achieved by even one enthusiastic landowner and, when you get a team working together, it is awesome. We've already managed to transform huge areas, and that gives us huge motivation to keep building our momentum."