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National strategy for invading conifers

A new report on wilding conifers proposes the development of a national strategy for the management of the vigorously seeding trees that have invaded hundreds of thousands of hectares of public and private land, particularly in the South Island in New Zealand. Source: Straight Furrow (NZ)

The report by Victoria Froude of Pacific Eco-Logic Ltd, commissioned by the former Ministry of Agriculture and Forestry, said that while a lot was known about wilding conifer risk there was no clear national picture of how successful current management was, nor whether the existing arrangements would be adequate for the future.

According to the report there are many examples of good progress in particular areas. In other areas, however, studies indicate a growing problem. Control techniques were generally well known and proven and early action was highly cost effective.

Conversely failure to follow-up after initial control meant gains were likely to be lost.

Ten conifer species are responsible for most of the wilding spread, including two important commercial species – radiata pine and Douglas fir.

Of particular concern has been the spread of pines on hill and high country areas of the eastern South Island from Marlborough to Otago, where they threaten farm production, conservation values and the magnificent landscapes.

Many of the worst infestations result from windblown seeds from early Crown agency plantings for erosion control and for research. For example early Forest Service research plantings at Hanmer Springs in North Canterbury have spread widely onto Molesworth Station.

The report recommends the development of an accord between the forestry industry, Local Government New Zealand (on behalf of councils), Government departments and other stakeholders under the leadership of the Ministry for Primary Industries.

It says further work should be undertaken on the level of funding needed to effectively control wildings in priority areas and how cost should be apportioned between different parties.

Options should be looked at to fund the removal of the early Crown plantings that have caused a lot of the wilding spread. This would be a matter of good faith and prudent long-term environmental management.

The report recommends dealing with competing objectives that may hinder removal of wilding conifers on private land. In particular this refers to the Emissions Trading Scheme where in many situations there is nothing to stop landowners claiming carbon credits for wilding stands without any responsibility for subsequent wilding spread.