Is there anything good about pine trees? Apart from for the people who own the commercial forests, the foresters. What earthly good do they do? Sure, they bring in much-needed export earnings, an estimated $5.89 billion for the year ending June 2025. So that helps towards the GDP. But look at the costs associated with the Pinus radiata. And they're mainly on the taxpayer, not on the industry itself.

The foresters have said, look, if we had to pay the true cost of cleaning up the damage, cleaning up the rubbish, cleaning up the slash, we wouldn't have a business. And when you look at the sums, you can see why. We've seen the extensive damage that slash causes to farms and to infrastructure and beaches during floods. The debris chokes rivers, creates devastating debris dams and leads to environmental disasters with long-term ecological impact. And this is creating ongoing crises for local communities, for tourism, for fisheries. And last night, Country Calendar on TVNZ1 highlighted another problem with the pine forests, wilding pines.

Steve Satterthwaite, who with his wife Mary owns and operates Muller Station in the Awatere Valley in Marlborough, says we absolutely need to act now to tackle the problem of wilding pines.

If we don't stop these trees, eventually, the pastoral country from here to Kaikoura will succumb to being a forest of wilding pines. The downstream effects of that are water yield. So the Marlborough grape industry would be massively at risk of the rivers running dry, particularly the Awatere. And then you've got the risk of fire. If these mountain ranges got covered in pine trees, then the fire risk would be horrendous. It is so frustrating that despite it being the biggest environmental wilding disaster in New Zealand, it has not been funded at all under the national wilding conifer control programme.

Well not strictly true Steve. In May of this year, the government announced a 20% increase in funding to tackle the spread of wilding pines. Then in August, it was announced that $3 million over three years of this international visitor levy revenue will go to the National Wilding Conifer Control programme, in particular for work in the Molesworth and Mc Kenzie Basin areas.

This government says, and successive governments, previous governments have said  that they've understood the risk that wilding pines pose to the environment. And they've said the government is focused on protecting the productive heart of New Zealand's economy. Agriculture and Forestry Minister Todd McClay said wilding pines cost the rural community significantly, often the bane of farmers' lives, we have an obligation to work with them to control their spread and reduce on-farm burden.

More than 2 million hectares are affected by wilding infestations with more to come, as Steve pointed out. The baby trees are already seeding and spreading their seed. It's only going to get worse. Untreated areas are expanding by an estimated 5% each year. Left unchecked, the economic impact could reach $3.6 billion over 50 years. So you add that the cost of the cleanup of the slash to the cost of the wilding pines. Are we really making any money from our export earnings?

The reason that commercial forests and the Department of Conservation planted pines were good initially, in the first instance there was a desire to prevent the spread of erosion. It was thought that the pine trees would help stabilise land. It hasn't been entirely successful in some parts of the country, but it was thought that would happen. Yet again, it's unintended consequences. Now we've got more problems really than the pines are worth, haven't we? If the foresters are saying they can't really afford to clean up after themselves, otherwise their business is unsustainable. If you look at the cost of the wilding pine control, and hasn't the horse bolted? I mean, can you ever really get it back under control now?

If you look at the cost of the slash, and then you balance that with the export earnings. Is it worth it? 

LISTEN ABOVE

See omnystudio.com/listener for privacy information.