Saving Wellington’s precious native plants

11 October, 2004

Saving Wellington’s precious native plants

Moves are underway to save hundreds of indigenous plant species under threat of extinction in the Wellington region. Identifying 173 nationally -threatened and uncommon species of indigenous plants in the region, and 20 threatened plant communities, the Department of Conservation’s Wellington Conservancy wants to ensure that a representative suite of the region’s indigenous plant communities continue to exist in the wild as part of functioning ecosystems.

In collaboration with other agencies, communities and individuals with an interest in indigenous plant management, DOC is aiming to achieve eight plant conservation targets within the next 20 years. They include protecting and restoring 60 percent of the conservancy’s nationally-threatened and uncommon plant species in the wild.

At least one population of 60 percent of acutely-threatened plant species will be replicated and maintained in secure living collections, such as botanic gardens and plant nurseries.

Other targets in the conservancy’s Plant Conservation Strategy include three-yearly assessments of the regional and national conservation status of all plant species in the conservancy; protecting 50 percent of the conservancy’s most important areas for plant diversity; promoting education and awareness of native plants; building plant conservation capacity; strengthening national and regional plant conservation networks, and supporting the sustainable use of indigenous plant species of local importance as rongoa (medicine).

DOC Wellington Conservancy plant ecologist John Sawyer said since the United Nations Convention on Biological Diversity was ratified in 1992 there had been a continuing decline in the status of the world’s plant life. This resulted in a Global Strategy for Plant Conservation, ratified by the New Zealand government in 2001.

“There is now a need to work towards its national implementation through achieving local plant conservation targets.”

Management options include protection and maintenance of habitats, weed and animal pest control, enhancing existing wild populations and establishing new wild populations. Visitor impact will be monitored at key sites supporting threatened plant species and communities.

“With 55 percent of the threatened plant populations identified in the strategy occurring on private land, we will continue working with landowners to determine the best way to manage these important sites in future,” Mr Sawyer said.

“Many landowners strongly support plant conservation and are allowing projects to occur on their land. By doing so, they are real champions for conservation.”

Under the biggest threat in the Wellington conservancy are lowland and coastal plant communities, impacted by land development, wetland drainage, habitat fragmentation, browsing and competition from introduced species.

“Just 10 percent remains of the wetlands formerly known in the Wellington region and our dune plants, such pingao, spinifex and carex, are being invaded by introduced marram grass, trampling and motorised vehicles,” Mr Sawyer said.

Forest communities dominated by tree fuchsia (Fuchsia exorticata) are also in serious decline.

High protection priority will be given to around 40 of the most acutely-threatened plant species. They include the tiny pygmy button daisy (Leptinella nana), which grows on rocky cliffs and gullies and can only be found in the Wellington region near Porirua. It is succumbing to weeds and trampling, earning itself a place on both the nationally-endangered and regionally-threatened lists.

Fires, slips and development of lowland forest remnants are behind the critical status of Olearia gardeneri, and heart-leaved kohuhu (Pittosporum obcordatum) - both under serious threat nationally. In the Wellington region these species are reduced to small populations in the Wairarapa.

Cook’s scurvy grass, Lepidium oleraceum, used by Captain James Cook to prevent scurvy, is diminishing partly through a decline in seabirds and seals along our coastlines. It is believed the plant grows better in soils enriched by sea bird droppings (guano) and/or seal faeces. Weeds and plant collectors have also contributed to its nationally-endangered status.

Plant collectors have also played a role in serious decline of the forest orchids Drymoanthus flavus and Plumatochilus tasmanicum.

Urgent attention will also be given to shrubby tororaro (Muehlenbeckia astonii), nationally-vulnerable, and wood rose – the most nectar rich plant in the world, Pua o te Reinga (Dactylanthus taylorii), in serious decline nationally.

Various other native species, such as the coastal dune plant spike sedge (Eleocharis neozelandica), tufted hair grass (Deschampsia cespitosa), yellow and tussock sedges (Carex flaviformis and Carex appressa), and yellow-flowered mistletoe (Alepis flavida) are already extinct in the wild in the Wellington region.

Seven species, including the Castlepoint daisy (Brachyglottis compacta), Tararua lacebark and matipo (Hoberia aff. sexstylosa and Myrsine aff. divaricata) are found only in the Wellington region. They are monitored regularly to ensure they are not in serious and irreversible decline.

The immediate focus for the strategy is the protection of :

173 nationally-threatened and uncommon indigenous vascular (veined) plant species 254 regionally-threatened and uncommon indigenous vascular plant species 11 nationally-threatened mosses and liverworts 20 threatened plant communities

Mr Sawyer said significant advances had been made in plant conservation in the Wellington Conservancy since the preparation of the first Plant Conservation Strategy in 1996.

“A national data base established in 1993 (Bioweb) now contains almost 13,000 records of occurrences of threatened plant species in the Wellington Conservancy. This accounts for 35 percent of all native plant records on the national database.”

Some threatened species populations had been rediscovered, and others were being captive-bred at such sites as traffic islands.

“The greatest achievement though is the increased awareness over the past eight years of the importance of native plants in our landscape, and the need to protect their ecology and habitats.” Mr Sawyer said. ENDS

Captions: DOC plant ecologist John Sawyer with the nationally-threatened Euphorbia glauca (sea spurge) which is being captive bred in traffic islands and urban reservations. It used to occur around the Wellington coast, including Pukerua Bay, but it is now only found in the Wellington region on Kapiti Island.

DOC plant ecologist John Sawyer with the nationally-threatened shrubby tororaro (Muehlenbeckia astonii) which is now being captive bred in traffic islands and urban reservations, and restored to reserves and islands in the region. It is found in the wild only in isolated locations around the Wellington south coast and eastern Wairarapa coast.

DOC plant ecologist John Sawyer with the nationally-uncommon fierce lancewood (Pseudoparax ferox) which is now being grown in captivity for reintroduction to new sites. It is found in the wild at only one site in the region, on the southern Wairarapa coast.

DOC plant ecologist John Sawyer with the nationally-threatened New Zealand iris (Libertia peregrinans), a coastal plant found in only a few locations in the Wellington region, including the northern Kapiti coast. It is being cultivated at Otari Wilton’s Bush and plants are being restored to coastal restoration projects on the Kapiti coast.

ENDS

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