Gorse outside Howard - St Arnaud

(Ulex europaeus)

Boundary Control Pest

Gorse is a woody perennial, with deep, extensive, lateral roots. It forms dense, spiny thickets. Flowers are deep yellow and form pods that disperse seeds ballistically, but they also spread via water, animals, and potentially in gravel. 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 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. On extensively grazed areas, plants can spread from infested sites to adjacent clear land.

Gorse is assessed at “7” on the infestation curve. Gorse is widespread throughout the Tasman-Nelson region, except the Howard - St Arnaud area, where the lower level of distribution makes it still feasible to progressively control Gorse and for the benefits to outweigh the costs. Elsewhere, where progressive control was required under the last Strategy, 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 that is clear, or being cleared of Gorse, from invasion from adjacent land by Gorse. Extensive areas of suitable habitat, and the potential for it to cause significant adverse effects, mean the benefits of boundary control far outweigh the costs.

Objective

To control the spread of Gorse from adjacent properties to land that is clear, or being cleared of Gorse, in the Tasman- Nelson region 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 the prevention of the spread of Gorse to adjacent properties where there is no Gorse, or where control is being carried out. Requiring a greater level of control, instead of just boundary control, is not appropriate given the widespread distribution of Gorse, and that the occupier is the main beneficiary.

Strategy Rule for Gorse

The occupier shall destroy all adult and juvenile forms of Gorse located up to 10 metres from the boundary of the land that they occupy where the adjacent property is clear, or being cleared of Gorse. A breach of Strategy Rule 7.6.5 is an offence under Section 154(r) of the Biosecurity Act 1993.

Explanation of Strategy Rule

The Management Agency will limit its intervention to enforce compliance of the rule to occasions when a reasonable complaint is received from an adjoining land occupier. This would require the complainant’s land to be already clear, or being cleared of Gorse, and that any invasion of the pest plant through the boundary has the potential to cause economic harm to the complainant’s land.

Biosecurity Act Requirement

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