Bolstering local plant populations through propagation

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 SinclairHead 10_reduced

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.

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. 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 WaipapaStreamTeKopahou 7_reduced

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.

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, 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.

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 many have afforded some protection to these plant populations. Photo Leon Perrie. © Te Papa.

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.

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.

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.

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.

5 Responses

  1. Nick Saville

    Nice work. Is it possible to eliminate the goats in the area as they appear to be a big threat? Or is that too tricky.

    Reply
    • Leon Perrie

      Hi Nick,

      Pigs are also a problem for the indigenous plants in the area. We saw many large Aciphylla squarrosa speargrasses that had been dug up by pigs.

      Managing wild mammals in this area is tricky, as there is a mix of landowners with different views on the value of these mammals. Some are even encouraging the local wild pig population by putting food out for them. Some people value hunting opportunities more than their native plants (http://blog.tepapa.govt.nz/2015/10/01/do-we-need-new-zealands-indigenous-species/).

  2. Barbara Paulus

    Totally impressed that WCC have biodiversity staff who look out for plant populations. Keep up the good work and let us know what else you are involved in!

    Reply
  3. Astrid

    Great article Leon, do you know if Anita is collecting for a specific restoration project, or could the propagated material become available to a wider group. Stuart Park might also be suitable habitat for some of the species you’ve mentioned.
    Cheers

    Reply
    • Anita Benbrook

      The plants will go into sites around Wellington’s South Coast eventually, but mostly we are trying to grow an insurance population of these remaining few plants. We are looking at developing the techniques involved with propagating these species and creating some stock plants that will be held at both Otari and Berhampore Nursery. Ideally we always collect seed but for some species this is not a feasible option. Some of the plants will also find there way into established community restoration projects on the South Coast

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