Increasing plant populations through propagation is one way to help threatened species. Last week, Wellington City Council biodiversity staff collected cuttings and seed from several plant populations in the Te Kopahou area on the coast south of Wellington. I tagged along.
The targeted species
Muehlenbeckia astonii. A popular garden plant, but Nationally Endangered and very uncommon in the Wellington region. We found only about 10 individuals at this population. The polygons formed by the interlacing branches help distinguish this species from other divaricating plants. Photo Leon Perrie. © Te Papa.
WCC’s Anita Benbrook taking cuttings from a plant of Muehlenbeckia astonii that is tucked under a rocky outcrop. Photo Leon Perrie. © Te Papa.
Clematis afoliata. This leafless Clematis is nationally secure, but it is very uncommon in the North Island. Apparently, around Wellington, there is only a single population, on one hillside. Photo Leon Perrie. © Te Papa.
Clematis afoliata flower. Most plants were only in bud. Photo Leon Perrie. © Te Papa.
Sophora molloyi, Cook Strait kowhai, is Naturally Uncommon, and found only around the coasts of Cook Strait. Although it can grow several metres tall, many of the plants we saw were in grassland and low shrubland, and were almost flat to the ground. That’s probably because of the wind and browsing pressure. Photo Leon Perrie. © Te Papa.
Peperomia urvilleana, a coastal plant in the pepper family. It seemed to be persisting only where it was protected from browsers, out-of-reach on rock cliffs or under twiggy shrubs. Photo Leon Perrie. © Te Papa.
Spectacular, steep habitat
WCC’s Anita Benbrook in action. The steepness of the sites may have afforded some protection to these plant populations. Photo Leon Perrie. © Te Papa.
Staff from WCC’s Otari-Wilton’s Bush search a hillside for suitable source material. Photo Leon Perrie. © Te Papa.
Wellington’s south coast is a spectacular landscape, and more enjoyable on a good day.
Between Sinclair Head and Tongue Point, with the South Island in the distance. Photo taken mid-morning, with the sun yet to illuminate the south-facing hillsides. Photo Leon Perrie. © Te Papa.
Looking south-east-ish from a high point near Te Kopahou. Getting around this dissected landscape involves a lot of up and down. Fortunately, we had 4WDs (and permission to use the tracks). Photo Leon Perrie. © Te Papa.
Visitor information for Te Kopahou Reserve.
Why propagate these plants?
If the propagation is successful, the new plants will be used to supplement existing populations and create ‘insurance’ populations.
If you’re wondering why bother, check out the blog post Do we need New Zealand’s indigenous species?
But I’ll also add that the evolutionary legacy and ‘potential’ of a species is generally distributed across its different populations. That gives purpose to conserving regional representatives of even species that are not threatened nationally.
For an example of genetic variation in a New Zealand plant species, see the blog post DNA fingerprinting fierce lancewood.