Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Conservation status of indigenous vascular plant species in the Wellington region Other Publication

Crisp, P.
Publisher / Organisation
Greater Wellington Regional Council
The New Zealand Threat Classification System (NZTCS) provides a tool for assigning a threat status to candidate taxa at the national scale. These threat rankings form the basis for prioritising conservation management actions, research and monitoring, and natural resource management decisions (Townsend et al, 2008). The NZTCS is effective at the national scale, but regional councils need local data for managing and protecting biodiversity within their regions. While the Department of Conservation (DOC) is tasked with managing indigenous species nationally, regional and district councils have a statutory obligation to manage the habitats of threatened species locally under the Resource Management Act, 1991. A methodology to create regional threat lists was developed by a collaborative group comprising representatives from DOC, regional councils and a local authority. The resulting regional threat listing methodology leverages off the NZTCS, but applies a species population threshold adjusted to the regional land area under consideration (relative to the national land area) for species that are not nationally threatened. The assigned regional threat status cannot be lower than that of the national threat status, but can be higher, (e.g. a Nationally Vulnerable species could be assessed as being Regionally Critical). Other assessments made in the regional threat listing process include identifying populations that are national strongholds and the use of regional qualifiers, such as natural or historic range limits. The need for a regional threat list is evidenced by the ongoing loss of species from the Wellington region. While a particular plant species may not be nationally threatened, the loss of a species from part of its range is the ‘tip of the iceberg’. The loss of a species in a region may also result in the extirpation of a local form, type or variety of that species. Biodiversity decline is occurring across New Zealand. One of the keys to halting/reversing that decline is knowing where those declines are occurring. A regional threat list will aid the identification of those losses at a local level, plus provide information that can be used for national conservation status assessments.