Environmental Weeds in the Spotlight

Front cover of the PCE report on weeds

Major contributors of information and data for the report included regional and district councils, the Department of Conservation (DOC) and the Ministry for Primary Industries (MPI). MWLR also played a major role, with one of our plant invasion ecologists, Angela Brandt, being seconded to the Commissioner’s report team. The weed biocontrol group also had an opportunity to provide input.

The report is much longer than would be expected for documents of this type. This is perhaps quite fitting given how massive the issue of invasive weeds is. The report puts this into perspective in black and white: New Zealand is far more concerned about the environmental impacts of a handful of the worst naturalised mammalian predators than it is about the hundreds of invasive environmental weeds and the many, many more naturalised plant species that are already found in our native ecosystems. The Māori world view of ‘what is a weed’ gets a special focus in the report and provides a sound reminder of the subjective nature of declaring any plant a weed. The Māori world view also gives a special reminder of the upset to the balance of ecosystems by a weed rather than any inherent properties of the weed.

In providing a summary of the report, it’s important to point out what the report does not do:  it does not identify which invasive weed species should be prioritised for management, and it also doesn’t evaluate the effectiveness, or other properties, of any weed management methods. What the report does is identify four key focus areas on how the current biosecurity system in New Zealand deals with weeds of native ecosystems, and recommends what a well-functioning system would do in each of these areas.

1. We don’t really know what’s out there. Although the report acknowledges there is plenty of information being collected, there are several key issues: the information is stored in multiple databases that do not connect; much of the information is either difficult to access or inaccessible; the taxonomy used in different databases is not standardised; and systematic surveillance of weeds is lacking. The report proposes a vision for what a good information system could look like, highlighting that the information must not only cover weeds that are already harming native ecosystems, but all exotic plants that have naturalised here. We cannot target weeds early on the invasion curve if we don’t know they are becoming a problem. National priorities can save a lot of time and a lot of limited resources that are currently wasted on prioritising weeds regionally and deciding management options. Even with clear national priorities we would still need improved tools to support management actions on any scale, starting with a national weeds database that follows an agreed taxonomy, gets regularly updated, and is linked to spatial distribution information to guide decisions about emerging weeds. The report recommends that MPI work with other relevant ministries, regional councils and Crown research institutes to “develop, administer and maintain a single authoritative and publicly accessible database” for this purpose.
2. We don’t have a good way to prioritise which weed species to manage in native ecosystems. The well-realised fact is that we are operating in a system that has limited resources, both financial and human, so we won’t be able to manage all ecosystem weeds, let alone all naturalised species that have not yet become a serious problem. Trade-offs are inevitable, but are they transparent? The report asks what systems are used to guide decisions on where to mobilise scarce resources. Are we only looking at the current worst offenders, or do we try to manage future challenges early on? Do we have the evidence we need to make these decisions, and is the system for prioritisation flexible enough to adapt to new information? Do we know with sufficient clarity what the goal is in the long run? Are we allocating enough resources to be able to reach this end goal? Or are we setting ourselves up for failure? The report suggests that it is the role of the Minister for Biosecurity together with the Minister of Conservation to provide a clear direction on priorities. The report also recommends that the ministries and regional councils work with iwi and hapū and other relevant organisations to coordinate the management of new, emerging weeds of native ecosystems.
3. The regulatory framework we operate under is complex, to put it mildly. The Biosecurity Act 1993 spans pre-border, border, and far past the border, covering an enormous range of living organisms with vastly different biologies, invasion paths, risks and management options. The biosecurity system that results from this Act puts an enormous amount of focus – and rightly so – on how to prevent unwanted organisms from entering the country in the first place. But it has little to offer on where to direct attention when it comes to species that are already here, are well established, and are causing harm. In addition, the biosecurity system spans many vastly different agencies: central government, local government, industry and communities. It is not at all straightforward to understand how the variety of entities that deal with weeds of native ecosystems are intended to work together. And, lest we forget, some weed control activities are governed by additional Acts, mainly the Resource Management Act 1991 and the Conservation Act 1987, so it is not always clear who is responsible for taking action. The stark fact that a national pest management plan and a national pathway management plan have never been prepared for a terrestrial exotic plant (harmful or otherwise) under the current regulatory system indicates that this group of organisms is not regarded as a high priority, certainly not as high as it ought to be. New Zealanders appear to be far more captivated by the harm caused by a small number of species of destructive mammalian predators than they are by the slow, encroaching, equally serious harm caused by weeds of native ecosystems.
4. New Zealand’s biosecurity system lacks coordination, direction and clear leadership at a national scale on managing weeds of native ecosystems. More specifically, the report highlights that under the Biosecurity Act it is the role of MPI to provide overall leadership in this area, but that in practice MPI focuses on pre-border and border incursions, and relies on DOC, councils, landowners, and local communities to manage weeds and run surveillance programmes. The report acknowledges that this approach can work, at least to some extent, for weeds in the productive sector, where managing weeds makes economic sense. But an economic case is more difficult to make for weeds of native ecosystems, where public funding is required. Consequently, some weed problems grow far beyond the ability of regional authorities and local efforts, and by the time MPI steps into the role of national coordinator of the problem it is too costly and too late. Wilding conifers are the key example for this type of scenario, where MPI has taken the lead on coordination and is investing $100 million in controlling a problem that has been escalating for decades on a highly visible trajectory. We simply cannot afford for more weeds to reach this devastating stage. Other agencies, such as DOC and regional councils, are not at all well positioned to take national coordination roles on weeds of native ecosystems. Since the current legislation does not provide a clear framework for a nationwide approach to weeds of native ecosystems, the report proposes that a way forward could be for the Minister for Biosecurity and the Minister of Conservation to jointly provide direction. Furthermore, it proposes that MPI and DOC work closely with regional councils to develop a national policy direction on weeds of native ecosystems. It also recommends that iwi and hapū be engaged on a national policy direction. It may be that amending the Biosecurity Act would be the most efficient way to enable such national policy directions, not only for weeds of native ecosystems but also for other groups of pests.

The report also acknowledges that even with good national-level coordination and resourcing, a top-down, centralised approach is not going to be enough when it comes to weed management. The role of grassroots (or weed-roots, as the report calls them) initiatives is highlighted as an essential component for a successful way forward. National coordination will be hugely important for sharing the technologies and solutions these local groups come up with, widely sharing their unique local insights and long-term perspective, and securing their ongoing funding.

Finally, the report reminds us that we must take a deep, long breath when we think about weeds of native ecosystems. Their management is here to stay, and we, as a country, must recognise this commitment. Of course adopting these recommendations by government requires resources to be associated with their implementation. But at least no government, now or in the future, can claim ignorance of the seriousness of the threat of weeds to native ecosystems.

The weed biocontrol group was fortunate to have an opportunity to engage with the Commissioner and his team while they were working on the report. Although biocontrol does not feature in the report, we feel we were able to showcase an excellent model for national coordination in the form of the National Biocontrol Collective, and spur hope that there is an effective option for managing environmental weeds.