Wilding Pine Control Marlborough Sounds

Wilding pines are a huge problem in the Marlborough Sounds and in 2007 a group of residents and holiday home-owners got together to form the Marlborough Sounds Restoration Trust to deal to pines.

Sara Archdale, trustee of the Marlborough Sounds Restoration Trust, says they have been a festering sore for decades. “We all feel pines really detract from the landscape values.” They reduce the bush-clad values of the landscape, displace native vegetation, affect soil and water values, including fish and invertebrates.

The target area at the moment is the whole of the inner of Queen Charlotte Sound. The trees were not planted, but have spread from homestead and woodlot plantings. This can be deduced from the pattern of how they have spread.

Much of the land in the Sounds was burnt off after the war, and the majority of the pines are around the same age, dating from spread which occurred at this time. The burning gave them a chance to spread.

Sara says while there are programmes to control wilding pines in other parts of NZ including Southland, Central Otago and the Rotorua area, what is unique about the Sounds is that the project is driven by tourism and the residents rather than by threats to farming – as is the case in many of the other projects.

The Marlborough Sounds Restoration Trust – whose patron is Sir Paul Reeves – was set up in 2007, and a strategic plan was written for three years to which clearly shows management areas being targeted, what funding is required, and how the project will be managed each year. “It is very structured and very clear, and I think it is very easy for people to relate to,” Sara says.

Also, this is a community-led initiative, not done by Government departments, and that appeals to people. It is also a good example of Kiwi initiative in getting in to solve a problem, she says. There’s good support from the local Marlborough District Council and from DOC though.

Having the Trust in place, along with the strategic plan, gives a vehicle to apply to funding agencies.

In year one 2007/2008, the budget was $130,000, much of which came from the NZ Lottery Grants Board, the Biodiversity Condition Fund and NZ King Salmon. There was lots of support from the community, for example accommodation for the contractors, transport on the water, and a lot of other in-kind support.

This year the budget is $212,000, and by the time of filming the Trust should know the outcome of its bid to the Lottery Grants Board. This year $20,000 has come from the community, in amounts which vary from $50 to $5000, mainly from people with holiday homes, or from permanent residents.

Next year the budget is around $160,000.

So that’s around $500,000 over three years, and for that money it’s extraordinary what they are able to achieve, Sara says.

Sara joined the Trust last year; she has lived in Picton for 14 years, so counts herself a long-term resident of the Sounds. “We like to be involved in environmental projects where we can.”

She was impressed with the strategic approach the Trust has taken to the problem, and says its success to date is because it has such a clear plan of the problem and how to address it.

“I think we are very fortunate that our chairman Andrew Macalister who is a third-generation holiday home owner is very passionate about the place he plays in, and is also a highly experienced biodiversity consultant.”

There are also other people on the Trust, and the Trust employs private contractors – four teams of four people who have come in from the West Coast, and from Nelson and Marlborough to carry out the work.

There’s a tendering process, and it is all treated very professionally with health and safety inductions, audits, GPS used to track the work, weekly monitoring and physical checking.

In the first year some 2500ha of land was targeted, with 8466 trees controlled, with about a 95% success rate to date. (It works out to a cost of around $15/tree)

The contractors face an incredibly difficult job Sara says: they have to carry petrol driven drilled into the bush, up to 8litres of herbicide, a first aid kit, food and water, and a saw. There are no tracks, so they need very good bush navigation skills. “They do an amazing job.”

Areas around boat sheds, homes and power lines are excluded. Some of the trees are felled, but not all.

The objective is not to get rid of every pine tree, but to control the problem and contain it. Sara says for example in 50 years there will be landscapes with no pines in them.

After three years the Trust hopes that at least 75% of the wilding pines in Queen Charlotte Sound will be controlled. The work is being carried out on both Crown and private land, and landowners don’t have to pay for the work to be carried out, but they are asked for their permission to do the control work. Almost all the landowners have agreed to this happening.

Seedling trees are pulled out by hand, and saplings cut with a pruning saw. They have to be cut close to the ground to ensure that no green needles are left.

Emergent trees are drilled with up to eight holes, each of which are filled with 10ml of metasulphuron, a commercial herbicide. It is totally contained in the hole, and doesn’t come into contact with soil, air or water.

This prevents the tree from photosynthesizing. The leaves turn brown, the tree dies, and branches start to fall off. A grey spar is left which eventually falls.

It takes about eight months from treatment to when the trees turn brown, and might take three years before the tree is completely dead.

Sometimes the trees are felled, but not often. Often felled trees create more problems such as opening up light wells for seedlings to germinate.

The project is likely to spread to the other sounds in time. There is a great deal of interest in the project, Sara says, and there’s been a lot of very positive feedback.

“People see it and want to be part of it and want to contribute. There will be some who find it disturbing seeing these brown trees in the landscape, as they wont’ be the most attractive, but the long term benefits are worth it.”