 Animal Pests and Weed Information
The deterioration of our stream bank ecology through invasive weedy and exotic woody streamside vegetation such as wandering jew, ginger, bamboo, willows and privet, is also cause for serious concern, as it affects the health and wellbeing of our native wildlife and our plants.
These species cast heavy shade over banks and prevent the establishment of other plants below them. As they don’t have substantial roots to bind and hold soil, they don’t prevent the erosion of our stream banks, as native stream bank shrubs and trees can.
When we have well established vegetation, it acts as a buffer zone for water on its way to the stream, slowing it and allowing soakage into the soil for plant use, while filtering out metal pollutants and stopping sediment runoff.
The deterioration of our stream bank vegetation to its current state of predominantly weeds and exotics, has had a major impact on native bird species in the area, as weeds and exotics don’t support native birds as they don’t bear berries. There is no natural dispersion of native seeds, nor can any dropped native seeds penetrate the dense weedy ground cover.
The native insects, lizards and invertebrates on which our birds also feed, require good quality habitat with many different species of non weedy vegetation.
An improved stream bank habitat will enable a return of these species. Improved stream banks will enable the movement of birds and insects through vegetation corridors, for the wider community to enjoy.
Improving the in-stream habitat quality and diversity for native fish, banded kokopu, inanga, koura, eels and fresh water shrimps can be achieved by providing woody debris and rock mounds in the water to provide shelter and breeding sites. Their food, the comparatively rare aquatic mayflies and stoneflies, is pollution sensitive and as the flooding continues to affect water quality, these species will continue to decrease. Diverse vegetation on stream banks will provide habitat for the insects, that are food for the fish.
The Auckland Region has over 615 introduced plant species which self propagate in the wild. Many of these are considered weeds, but only some cause serious harm to the environment or economic loss to producers. The Surveillance Pest Plant category in the Auckland Regional Council “Regional Pest Management Strategy” contains 82 plant species that have been identified as actual or potential risks to the Auckland Region. They are all banned from sale, propagation, distribution and commercial display within the region. The majority were brought to New Zealand as ornamental/garden species or as contaminants in seed.
Other pest plants within the strategy include:
Service Delivery PestPlants – are plants that are of limited distribution within the Auckland Region. The Auckland Regional Council is responsible for controlling these plants, and in the long term eradicating them from the region, before they become widespread as plant pests.
Total Control Plant Pests – are plants which you must treat if they are growing on your land. The Auckland Regional Council hope to lessen the impact of these plant pests on the environment and people’s health and activities, by ensuring all sites in the Region are treated at regular intervals by land occupiers. Continued treatment will make sure that the number of plants are gradually reduced. IN the long term we may even be able to eradicate some of these plants. Plants include, nodding thistle, ragwort, moth plant, woolly nightshade.
Boundary Control Plant Pests – are plants which need to be controlled on rural property boundaries, so that they don’t infest neighbouring properties. If you have any of these plants pests on your property, you will need to control them within a specified distance from you r boundary. Plants include, Australian sedge and gorse.
Monitoring Plant Pests – are plants which are of potentially high risk to the Auckland Region. Currently, not enough is known about these plant pest distribution, ecology and possible control methods to attempt control. Plants include, sweet pea shrub, bushy asparagus, lantana, purple nut sedge.
The public is encouraged to protect the environment by removing them from their property. Initiatives to control these pest plants include:
- controlling pest plants on your property
- disposing of pest plants safely
- watching out for the spread of new plants
The Auckland Regional Council’s Biosecurity Officers are available to help identify invasive, unusual or unwanted plants on your property. Officers can also assist the public to formulate control programmes for various plant pests. These programmes may include the regular use and application of herbicides and methods which minimise their growth eg: cut and inject or stump swabbing methods. Advice can also be obtained on suitable non-chemical or organic control methods. These may include mechanical methods of plant pest removal, the use of goats or other stock, pasture management or the establishment and extension of biological control programmes with insects, especially for ragwort and gorse control.
For futher information on individual pest plants, and on friendly alternatives to plant in their place contact: Auckland Regional Council’s Enviroline on 0800806040
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