Purple Pampas is a tall, erect, tussock-forming, perennial grass growing up to 2-3 metres high. It starts flowering in late January. Purple Pampas has dark green leaves and its flowering stems, up to 3 metres high, have distinctive, erect, fluffy, purple flower heads that fade with age. This species was planted for shelter belts; its seeds can be carried for more than 20 kilometres downwind. The combination of prolific seeding, extensive wind distribution, and its ability to colonise disturbed land from sea-level up to 800 metres and dominate the site for many years, make it a serious long-term pest. Purple Pampas is distinguishable from the three native toetoe species, which have more creamy-yellow heads, and from Common Pampas (Cortaderia selloana), which starts flowering in mid-March.
Reasons for the Strategy
Purple Pampas impacts on plantation forests by smothering recently-planted seedlings. It can also suppress the growth of smaller native species, especially in coastal areas, regenerating shrublands and bush margins. Purple Pampas is targeted rather than Common Pampas, as it has the ability to produce fertile seed from individual plants without pollination.
Purple Pampas is assessed at “5” on the infestation curve. It is widespread throughout the Tasman-Nelson region, including Golden Bay and its presence in plantation forests and reverting shrubland make surveillance difficult. Extensive areas of suitable habitat, and the potential for it to cause significant adverse effects, mean the benefits of containment control far outweigh the costs.
To address the adverse effects of Purple Pampas in the Tasman-Nelson region by preventing any increase in its distribution and density during the term of the Strategy.
The alternative option of “do nothing” or relying on voluntary control will not achieve the objective of reducing the distribution and density of Purple Pampas, and will result in significant additional costs to the community with respect to lost production and natural values, and the increased cost of control in the future. Requiring total control is not practical given the difficulty of identifying and controlling it in forest plantations, shrubland and on broken terrain.
Strategy Rule for Purple Pampas
The occupier shall destroy all adult and juvenile forms of Purple Pampas on land that they occupy. A breach of Strategy Rule 6.9.5 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 Purple Pampas, under Sections 52 and 53 of the Act.