Gorse - Howard - St Arnaud

(Ulex europaeus)

Containment Pests

Gorse is a fast-growing woody perennial, with deep, extensive, lateral roots. It forms dense, spiny thickets up to 2.5 m high. The flowers are deep yellow and form pods that disperse seeds ballistically. They are also spread by water, animals, in gravel extracted from waterways and in mud on machinery and vehicles. Seeds remain viable for many years. Gorse will regrow if cut or burnt.

Reasons for the Strategy

Tall green stalks with yellow flowers that make up the gorse woody plant.

Gorse is a serious production and environmental pest in the Tasman-Nelson region. It is an aggressive competitor for light, nutrients, and moisture. Gorse restricts grazing by displacing preferred pasture species and its prickly nature impedes stock access. Spiny twigs lower the value of wool and foraging by sheep amongst Gorse pulls fleeces. The plant provides habitat to animal pests such as possums and rabbits, and in places presents a serious fire hazard. Short or open non-forest communities can become overwhelmed by Gorse, and it impacts on natural and recreational areas through obstruction or degradation of amenity values. It competes aggressively with native plants and will remain as the dominant species for many years. On extensively grazed areas, plants can spread from infested sites to adjacent clear land.

Gorse is assessed at “4” on the infestation curve for the Howard-St Arnaud area and “7” for the rest of the Tasman-Nelson region. Gorse is widespread throughout most of the Tasman-Nelson region, except in the Howard-St Arnaud area. The low incidence of Gorse in the Howard-St Arnaud area, extensive areas of suitable habitat, and the potential for it to cause significant adverse effects, mean the benefits of containment far outweigh the costs. Elsewhere, the distribution of Gorse has reached a level where the most cost-effective form of control is to require boundary control, and to invest in biocontrol. This will assist in protecting land clear, or being cleared of Gorse, from invasion by Gorse growing on adjacent land.

Objective

To address the adverse effects of Gorse in the Howard-St Arnaud area by preventing any increase in its distribution and density during the term of the Strategy.

Alternative Measures

The alternative option of “do nothing” or relying on voluntary control will not achieve the objective of reducing the distribution and density of Gorse in the Howard-St Arnaud area, and will result in significant additional costs to the community through lost production, and the increased cost of control in the future. Requiring progressive control throughout the Howard-St Arnaud area would not be costeffective given its distribution and persistence.

Strategy Rule for Gorse

An occupier in the Howard-St Arnaud area shall destroy all adult and juvenile forms of Gorse on land that they occupy. A breach of Strategy Rule 6.x.5 is an offence under Section 154(r) of the Biosecurity Act 1993.

Biosecurity Act Requirement

No person shall knowingly sell, propagate, breed, release, or commercially display Gorse, under Sections 52 and 53 of the Act.