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Monday 15 November 2004 : Global Plant Conservation in New Zealand – a way forward for the 21st Century.
Speaker John Sawyer, Technical Support Officer, Wellington Conservancy, DOC.
After first mentioning how his initial interest in the preservation of flora and fauna came from the closeness of nature to his family home where he grew up in the west highlands of Scotland, John proceeded to introduce the conservation status of NZ Plant Life.
New Zealand has been internationally recognised as a biodiversity hotspot. This is especially true when you consider our flora. Eighty percent of all New Zealand’s native plants are endemic, i.e. that are found nowhere else in the world. Thus we have a special responsibility to care for them in the wild. Centres of Plant Diversity lists New Zealand 21st out of 25 centres of Plant Diversity.
With the pressures of growing populations and urban sprawl, it is no wonder that we are losing native plants and the habitats they live in. John urged us to be more innovative about plant conservation.
While offshore islands offer a more traditional option for native plant conservation in New Zealand, traffic islands and road reserves are now being used in the Wellington region as an integral part of plant species recovery projects.
Traffic islands work as a conservation strategy because Councils have to plant there anyway, they provide insurance populations of endangered plants should wild populations be destroyed, offspring for revegetation projects, and a research and educational resource. These islands are well protected by the roads that surround them. Browsing animals, such as possums, are unable to access them and council staff keep the islands free of weeds.
The use of traffic islands for plant conservation was developed in Lower Hutt, where several organisations work together to ensure that rare native plants do not die out. One of the success stories is Muehlenbeckia astonii (shrubby tororaro). There were only 44 plants left in the wild, and male and female plants were so widely scattered that they could not produce seed. Now plants on traffic islands produce seed to grow plants for return to the wild, or planted in urban areas such as the Petone Esplanade. Here other endangered plants hardy to coastal conditions, e.g. Euphorbia glauca, Hebe speciosa (Port Waikato) and Discaria toumatou (Matagouri), are also grown.
Threatened plant species grown in traffic islands can be valuable components of a plant conservation programme as well as contributing to an attractive urban landscape.
John went on to describe the structure of the Threat Classification System as defined by the New Zealand Plant Conservation Network; see www.nzpcn.org.nz. Each plant species is considered by a panel of experts, and classified according to the following categories.
| Category | Examples in category |
| The most acutely threatened species are those in the categories |
| Nationally Critical | Tecomanthe speciosa, Carmichaelia muritai, Coprosma spathulata subsp. hikuruana and Anzybas carsei, WN e.g. Olearia gardneri |
| Nationally Endangered | 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, and Brachyglottis huntii (Chatham Island Christmas tree – Rautini), |
| Nationally Vulnerable | Muehlenbeckia astonii (shrubby tororaro), Aciphylla dieffenbachii, Hebe barkeri |
| Chronically threatened species are those in the categories |
| Serious decline | Dactylanthus taylorii (wood rose) (pollinated by the short-tailed bat) |
| Gradual decline | Desmoschoenus spiralis (pingao) |
| Uncommon species are categorised as |
| Range Restricted | Atriplex billardierei, Xeronema callistemon (Poor Knights lily) |
| Sparse | |
| Other classification categories included are |
| Extinct | Trilepidec adamsii, Lepidium obtusatum |
| Coloniser | |
| Vagrant | |
| Data Deficient | |
The distribution of species according to their endangered classification as listed in the following table, shows that endangered species represent a high proportion of the total vascular flora of NZ, represented by 2345 taxa.
Endangered
classification | Described Taxa
(2345) | Indeterminate or
Undescribed taxa |
| Extinct | 4 - 0.2% | 2 |
| Acute | 121 - 5% | 54 |
| Chronic | 97 - 4% | 12 |
| At risk | 502 - 21% | 89 |
| TOTAL | 724 - 31% | |
As well as threatened plants, there are also some whole plant community types that are threatened. Examples include :
- Dunes
- Ephemeral wetlands
- Geothermal scrub
- Scree scrub
- Coastal cliffs
John then described the HIPPO effect, an acronym categorizing the reasons for species decline.
| Decline category | Description |
| H – Habitat Loss | When the native plant and animal life of an area are destroyed, e.g. Canterbury plains clearances for farming/cropping, and suburban development. |
I – Introduced Species
(exotic and invasive) | When a species not native to an area has been introduced to a new area, often unintentionally, the exotic species will tend to multiply and crowd out native species, e.g. Tradescantia fluminensis in N.Z. With 25,000 exotic plants in NZ escapes from gardens is a severe potential treat. |
| P – Pollution | Can affect air, water, and soils; e.g. climate change as a result of human effects on atmosphere, carbon dioxide emissions, resulting in 0.6°C increase over last 100 years. May seem small effect but results in phenology distribution changes, community composition, reduction of ranges, ecological changes.
Also gene pool pollution due to hybridization with introduced species, e.g. Ngaio and boobialla (“Tasmanian ngaio”), and species being planted outside their normal natural range e.g. pohutukawa and northern rata. |
| P – Population Growth | Having the effect of humans crowding out other species. |
O – Over-consumption
(Over harvesting) | Depletion of natural resources and illegal harvesting, e.g. recent cases where rare NZ native plants have been attempted to be smuggled out of the country. |
John illustrated through examples some threats to natural vegetation succession caused by human activities. These included :
- Lack of renewal of manuka scrubland owing to increased control of fire has resulted in a reduction of greenhood orchid habitat,
- Control of fires in wetlands has changed the natural germination cycle of some plant species, and
- The spread of diseases from exotic plants to native species; e.g. white rust (Albugo candida) commonly found in Brassicaceae garden crops will also attack Lepidium oleraceum agg. in cultivation.
John then posed the question of what are the responses we should be undertaking to secure the recovery of threatened plant species.
He outlined the 8 P’s – each describing a work area within DOC.
| Planning | Based upon the Global Strategy for plant conservation 2002 that has been endorsed by 187 countries, the NZ Biodiversity strategy 2001, and the Plant Conservation Strategy for Wellington Conservancy - 16 targets.
Achievements. 10,000 plant check lists, 13,000 plant records made, action plans for threatened plants published, 17 native species recovery plans published. |
Protection
(highest priority) | • Survey – results in plants found for first time or rediscovered and new species found,
• Undertake regular monitoring of threatened populations (plant monitoring guidelines are being prepared) 350 nationwide and 44 in Wellington,
• Lobbying to provide legal protection on private lands of threatened plant communities,
• Lobbying to provide physical protection of threatened plants e.g. fencing from stock,
• Undertake Research. |
| Pests | Monitoring, alerting and eradication of pests to threatened plant communities. e.g. Italian Buckthorn (Rhamnus alatemus) – an emerging pest plant problem for Wellington. |
| Planting | e.g. planting of Muehlenbeckia astonii by Hutt City Council on traffic islands |
| Promotion | Raising public awareness of threatened plants – e.g. Tourism New Zealand’s 100% Pure New Zealand Ora – Garden of Well-being was one of four gardens to take away gold at London’s Chelsea Flower Show in May 2004 included rare NZ natives. |
| People | Never before has there been a time when there has been so many qualified botanical resources available e.g. within DOC, Landcare and tertiary institutions. |
| Partnership | Sponsorship of NZPCN establishment, now has 200 members, regular newsletter, and ongoing work areas. |
| Patience | Ongoing relationship building. Constant vigilance. |
So “what does future hold?”, John asked.
Early NZ naturalist and director of the Dominion Museum, Walter Reginald Brook Oliver said on 18th July 1938, “I want you to protect New Zealand’s plant life”.
“How do we do this?”
As individuals, we can survey, make ourselves aware of endangered species and threats, and check our gardens, neighbours gardens and garden centres for potential threats.
As a Society Wellington BotSoc should be seen as the Tane Mahuta of botanical societies and provide an example for others to follow. Some examples suggested of activities that BotSoc should be involved in to protect New Zealand’s plant life, were :-
Locally
• Bring in students as younger members to educate the next generation
• Undertake pest control and planting
• Expand, link and buffer existing restoration areas
• Lobby for the use of appropriate, locally sourced, native species.
Nationally
• Lobby for better native plant protection
• Lobby for protection of important plant community areas
• Liaise with other botanical societies
• Support NP Plant Conservation Network strategy
• Seek National funding from the Terrestrial and Freshwater Biodiversity Information Systems (TFBIS) programme to put BotSoc’s Bulletins and newsletters on-line as a readily accessible, indexed resource.
So what can we conclude?
• Plant conservation is multidisciplinary
• There is a need for improved global conservation strategies
• Threatened native plants are a serious issue that needs urgent and sustained action
• If we can’t do it in NZ, then there is little likelihood it can be achieved elsewhere in the world.
This present moment
That lives on to become
Long ago.
Gary Snyder
Richard Herbert
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