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Norfolk Island Flora & Fauna Society

Author Archives: Geoff Edwards

Madeira Vine

Updated on date by author

Madeira Vine (Anredera cordifolia) is a South American invader with bright green fleshy leaves and tubers growing both underground and at nodes along the trailing stems. There are numerous patches within the Hundred Acres reserve. The first photo is of a new patch heading up the nearest tree.

 

Once established, manual control is a painstaking task that must be repeatedly frequently to remove freshly sprouted bulbils before their tendrils generate strings of new ones. Also, it is very easy to mistake the worthy native spinach Tetragonia for Madeira Vine. In the second photo, a spinach is peeking out from the Madeira vine near the stick.

Posted in Introduced Flora, Invasive Weeds |

The Great Formosan Lily Hunt

Updated on date by author

 

For several years the Flora and Fauna Society offered a reward for collection of stems of the introduced Formosan Lily. These lilies are a very invasive weed and in some places, infestations have totally precluded any native species from continuing to thrive in their native habitat. They will grow in sun and shade, in wet and dry conditions, and on flat land, slopes and steep cliffs.

Windy conditions are perfect for the ripened seed pods to disperse their thousands of seeds.

A number of parents have expressed concern at the number of lilies, making it easy for their little collectors to see the purpose and so to get great results. We hope this results in a better understanding as to why this problem needs to be tackled soon in a strategic manner across the Island. If we allow all the soil and water, sun and shade to be used by white lilies that don’t belong here, we are denying the natives the ability to survive in the only place they know, and belong.

Members understand that we are not removing the problem, but are simply reducing the size of the population, which has the potential to expand exponentially if left unchecked.

If we are to preserve the island’s all-important native plants we need to make sure they have some space to grow. Without the native plants, we could lose our native insects and our unique bird species and the wonderful experiences we all enjoy through being in our precious environment.

 

Corms of Formosan Lily

Results

We have had fantastic results from our collectors in the three years 2017-2019. The project offered a bounty for Formosan Lilies collected in bundles of 50. Bounty 10c per stem + prizes of $100, $50 and $75 for the most stems collected.

In the summer season 2016-2017, a total of 257 bundles @ 50 stems bringing to a total of 12,850 plants were collected. With only a single flower per plant this has prevented the spreading of notionally at least 15,420,000 new plants. With some plants having been seen to have 12 flowers the potential increases to 805,040,000! Thanks so much to the collectors and their support teams for participating in this important project.

There was again a fantastic response in the 2018 Great Lily Hunt, resulting in the prevention of a possible 383+ million seeds germinating to make new plants. Due to the wet weather conditions at the time of the collection, some participants were also able to easily remove the bulbs along with the stems, making it a wonderful bonus number of possible future plants now not in the landscape.

In 2019 Society representatives, Liz Nobbs-Hewson and Bev Buffett presented certificates and cheques to students who participated in the Hunt. Total prize money was $4362.50, made up of a Community Grant from Norfolk Island Regional Council of $2500 with the balance of $1862.50 funded by Norfolk Island Flora & Fauna Society. Over 40,000 Formosan Lily plants were collected, preventing at least 86 million new plants being produced. Another fantastic effort!

In 2020 $5715 was paid in prizes. The Society thanks Norfolk Island Rotary and Foodlands for $2500 each in sponsorship.

Seeds of Formosan Lily

In 2021 the Society decided to review the project seek to have it mainstreamed into the official work program of the Council.

Posted in Formosan Lily, Get Involved, Introduced Flora |

Porpieh (Strawberry Guava, Cherry Guava)

Updated on date by author

Raw ingredient of tasty jam and jelly on the Island, and free of the fruit fly that in Australia beats humans to the ripening fruit, it has another valuable use. The timber is durable and widely used for tool handles and garden stakes. Yet Norf’k could do without this pest. From small bushes to dense thickets where it grows tall and straight, it is ubiquitous on the Island.

Posted in Cherry Guava, Introduced Flora |

Coral Berry crusade at Hundred Acres

Updated on date by author

Coral Berry, Rivina humilis, is a native of the Americas and a serious “environmental weed”. A dedicated group of volunteers has been working diligently to clear the Hundred Acres reserve of this pest. By the time that the reserve had been largely treated in the first round, the next generation of seedlings was ready to flower and the task recommenced, early in 2021. On Wednesday 28 July 2021 the group celebrated the first anniversary of its mission with special morning tea in the reserve. Contact the Society to join the crusade!

Organiser Judith Andersen at work

 

Posted in Get Involved |

African Boxthorn

Updated on date by author

African Boxthorn, Lycium ferocissimum, is a Weed of National Significance in mainland Australia. It’s a localised nuisance on Norfolk Island. Spines thick enough to penetrate car tyres can inflict painful puncture wounds in human flesh.

The photograph of Boxthorn covering slopes on the the Hundred Acres Reserve demonstrates both its ability to smother all desirable vegetation and also the need for very careful planning of control measures. Abrupt removal of the boxthorn would run the risk of irreversible soil erosion. However, boxthorn also tends to suppress the growth of grasses nearby and grasses are very good for protecting the surface of the soil from raindrop and wind erosion.

 

 

Posted in Introduced Flora, Invasive Weeds |

Phytophthora cinnamomi

Updated on date by author

Phytophthora is a group of microscopic soil-borne pathogens that can cause dieback and root rot in a range of different plants. Different species of Phytophthora can cause dieback and root rot in different plants. While most species of Phytophthora affect a limited number of plants, Phytophthora cinnamomi can affect a broad range of plant species.

Phytophthora are not visible to the human eye and don’t always cause symptoms. A plant may appear healthy for a long time and suddenly exhibit symptoms when conditions change, for example after an increase in humidity. This means that it can be challenging to know whether the pathogen is present or not.

There is debate in scientific circles as to the date of its arrival in Australia. The mainstream view is that the devastation caused to the jarrah forests in Western Australia and the heathlands along the east coast, particularly the grass-trees (Xanthorrhoea) and proteaceous species, points to a post-1788 introduction.

Is Phytophthora cinnamomi present on the Island?

Two snippets of evidence suggest “Yes”. A study in the 1970s reported finding the organism (Benson 1980), but the results cannot be confirmed.

A multidisciplinary plant health survey in 2012-14 covered introduced plants, invertebrate pests of plants and animals, plant pathogens, pests and diseases of bees and diseases and parasites of domestic animals. In total, 1747 species were recorded across all organism groups. Phytophthora cinnamomi was not specifically targeted, but a sample collected to test for another pathogen was found to contain Phytophthora, though it was not identified to species level at the time. The sample was re-examined in 2019 and identified as Phytophthora cinnamomi.

The two records were not considered to be sufficiently strong evidence on their own to make a determination on the status of this pest. For this reason, Australian Government scientists visited the Island in February/March 2021 to collect more samples.The survey team collected 67 samples and processed them on Island before sending to Sydney for diagnostics.

Plant pathologist Harshitsinh Vala germinates seed of lupin (very sensitive to P.c.) to aid in detection.

Scientists Elizabeth McCrudden and Sandy Perkins take soil samples.

The visiting scientists advised that “The success of this survey would not have been possible without the support and guidance from the Norfolk Island Biosecurity staff and the Norfolk Island community, who have allowed the team generous access to homes and properties to collect samples.”

Importation of aggregate

Importation of aggregate for the Norfolk Island Airport Pavement Repair and Resurfacing project raised some questions about the status of Phytophthora on the Island. It was decided to treat Norfolk Island as if it were free from P. cinnamomi when imposing conditions for the aggregate importation. This decision was made to afford the Island the highest level of biosecurity protection possible until more complete information could be obtained. The 2021 survey of samples collected on a grid across the Island is intended to fill the gaps in knowledge.

 

Posted in Introduced Flora |

Cats

Updated on date by author

Feral (wild) cats – and domestic cats on the prowl at night – have a devastating effect on native wildlife, which has not evolved to coexist with an efficient predator like the cat.

In April 2017, Margaret Christian of the Society prepared an brief explanatory memorandum which eventually accompanied a questionnaire for the people of the Island, conducted by the Norfolk Island Regional Council. The survey form presented three options:

Option 1 – Do nothing
Option 2 – Ban cats from Norfolk Island
Option 3 – Allow continued cat ownership under controlled conditions.

The survey revealed that 12% of respondents wanted cats banned completely and another ~68% wanted cats to be controlled. There was a vocal campaign by the cat lovers to be engaged in the survey. They took out half page advertisements in the paper, but the results showed that they were in a minority.

Unfortunately, the changes in governance came soon after and there has not been much progress towards establishing a Pound, one of the highest priority proposals that came out of the survey. However, the present Island-wide cat monitoring and some feral cat control has been funded by the Australian Government, using the survey results as evidence of the community’s attitude supportive of control.

 

Before ceasing, the Cat Welfare and Wildlife Protection Association of Norfolk Island transferred a significant quantum of its residual funds to the Society to ensure that any cats trapped would be treated humanely.

Posted in Cats, Invasive Fauna |

Myrtle Rust on Australia’s islands

Updated on date by author

Myrtle Rust is a fungal pest that slipped through Australia’s weak biosecurity defences. In 2017 Australia’s Invasive Species Council published a note about its arrival on Norfolk Island and on 17 May 2017 issued a press release:

“Over the past six months myrtle rust has been detected on both Lord Howe Island and Norfolk Island. Australian authorities have responded poorly to both outbreaks.

On Lord Howe Island, Lord Howe Island Board staff swung quickly into action to try to eradicate infected plants but received little support from the NSW government’s primary industry and environment departments beyond advice. Lord Howe Island Board staff had to rely on their own limited resources because myrtle rust is now considered “endemic” in NSW.

On a recent visit to Norfolk Island our CEO Andrew Cox discovered that myrtle rust had been found on planted rose apples (Syzygium jambos) six months ago. No public information about the detection has been released, and the federal agriculture department is still determining a response. The new Norfolk Island Regional Council seemed unaware of the arrival. Thankfully there are no native myrtles on the island.

Myrtle rust outbreaks on these two iconic islands should have been prioritised at state and federal levels. Once established, the rust could spread to other offshore islands and possibly to mainland New Zealand. Last month myrtle rust was found at Raoul Island, about 1000 km northeast of New Zealand and a similar distance east of Norfolk Island.”

Posted in Invasive Species |

Norfolk Island Conservation Volunteers

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Norfolk Island Conservation Volunteers (NICV) was formed in July 2020 under the auspices of the Norfolk Island Flora & Fauna Society Inc., and with the support of Norfolk Island Regional Council and Norfolk Island National Park.

 

The Coral Berry Crusade

The first NICV project, and the only project to date, has been tackling a heavy infestation of the very invasive coral berry (Rivina humilis) in 100 Acres Reserve. This South American native had established itself in the reserve over many years, and had become the dominant ground cover. Quick-growing and with numerous very hardy seeds produced per plant, its dominance was affecting other native ground cover, and also the slower growing seedlings of native trees and bushes, out-competing them for space, light, water and nutrients.

In its first year, NICV was able to make one full sweep through the reserve and was well into its second or in some spots, third sweep, aiming to catch the coral berry before fruiting  and thus progressively exhaust the seed bank. This strategy has been extremely successful so far, with coral berry now replaced by a delicate native herb, Parietaria debilis, as the dominant ground cover. Prior to this, P. debilis had become very scarce in the reserve.

In addition to coral berry, NICV has been pulling up other known weeds as encountered. These have included African boxthorn, silky oak, lantana, tomato, guava, ochna, cape gooseberry, black olive, Hawaiian holly, Morning Glory vine, Madeira vine, chickweed and milkweed.

As the work on coral berry now appears to be approaching maintenance phase, NICV is discussing options of extending into other reserves and the National Park, or remaining in 100 Acres but becoming more systematic in tackling the other weed species found there.

 

Posted in Get Involved, Invasive Species |