Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Critically Endangered
Listing and Conservation Advices Commonwealth Listing Advice for Norfolk Island Flora - 11 Critically Endangered Species (Threatened Species Scientific Committee (TSSC), 2003o) [Listing Advice].
 
Recovery Plan Decision Recovery Plan required, included on the Commenced List (1/11/2009).
 
Adopted/Made Recovery Plans Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010) [Recovery Plan].
 
Information Sheets What the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) means for Norfolk Islanders (Department of the Environment and Heritage (DEH), 2004i) [Information Sheet].
 
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (03/11/2003) (Commonwealth of Australia, 2003a) [Legislative Instrument].
 
Scientific name Hibiscus insularis [30614]
Family Malvaceae:Malvales:Magnoliopsida:Magnoliophyta:Plantae
Species author Endl.
Infraspecies author  
Reference Prodromus Florae Norfolkicae: 74 (1833).
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Other illustrations Google Images
http://www.anbg.gov.au/images/photo_cd/OF31S010626/072.html
http://www.anbg.gov.au/images/photo_cd/519816120330/026.html

Scientific Name: Hibiscus insularis

Common Name: Phillip Island Hibiscus

Phillip Island Hibiscus is a large shrub or small tree to 2.5 m high. Flowers are solitary and cream to light green coloured when they first open, with a dark magenta center, but turn reddish or purple as they age. The lobed leaves have a shiny upper surface, and are 3–5 cm long and 2–4 cm wide (DEH 2003c; Green 1994; Sykes & Atkinson 1988).

Hibiscus insularis is endemic to Phillip Island in the Norfolk Island Group, where the species is confined to three patches on the northern slopes (Green 1994; Mosley 2001). These plants have survived despite the grazing pigs, goats and rabbits which destroyed most of the Island's vegetation. With all of the introduced animals now removed from Phillip Island, seedlings are now growing near the original bushes (DEH 2003c).

Propagated populations of the species are also located at the Botanic Gardens on Norfolk Island and in Booderee Botanic Gardens in Booderee National Park (formerly the Jervis Bay annexe of the Australian National Botanic Gardens) (ANBG 1988; Director of National Parks 2008).

This species' distribution can be considered highly fragmented as it occurs only as small isolated subpopulations.

Sykes and Atkinson (1988) conducted a survey of the rare and threatened plants of Norfolk Island in 1987. Given the small size of the Island it is probable that the plants found in the survey are an accurate representation of the actual population size.

In 2003, there were fewer than 50 mature plants of Phillip Island Hibiscus growing on Phillip Island (TSSC 2003o).

In 1988, Phillip Island Hibiscus occurred as two small patches with respective diameters of 10 and 50 metres. By 2001 a third patch (10 by 50 m) had become established (Mosley 2001).

The natural population has increased from previously recorded population levels (13 plants in 1939, and only eight plants in 1963) (Green 1994).

Phillip Island Hibiscus is grown in the Norfolk Island Botanic Gardens, the Booderee Botanic Gardens in Booderee National Park (ANBG 1988; Director of National Parks 2008) and the Royal Botanic Gardens Melbourne.

The preferred habitat of Phillip Island Hibiscus is difficult to determine given the impact of feral browsing animals on the Island (Sykes & Atkinson 1988).

The Norfolk Island group has a subtropical climate and the volcanic soils are nutrient rich, friable and porous. They do not hold moisture well (BoM 2008; Director of National Parks 2008).

Phillip Island Hibiscus seedlings have very small leaves, which develop into a deeply lobed juvenile form. This stage may persist for up to 20 years before the adult leaf form is produced. Since flowers are only seen once the adult foliage is present, Phillip Island Hibiscus has a long generation time (Groeneveld 1989).

The flowers of Phillip Island Hibiscus grow in an upwards fashion at the ends of branches, with rarely more than one flower at the same stage on the same branch. Large amounts of nectar are produced. The flowers are female when they first open, and one day later they enter the male phase (at which point they are capable of self-pollination). Over the next few days the flowers turn pink and close up, then wither. Separation of the male and female stages by one day increases the opportunity for outcrossing (Groeneveld 1989).

This species is believed to be bird-pollinated, but it is possible that the original pollinating species has become extinct. Phillip Island Hibiscus is capable of producing seeds by self-pollination, and is also capable of vegetative reproduction through stem-layering (Groeneveld 1989).

In the past, Phillip Island Hibiscus has been threatened by grazing and habitat degradation by the feral pigs, goats and rabbits that occurred on Phillip Island. However, these species have now been removed from the Island and no longer pose a threat to the native vegetation (Green 1994; Groeneveld 1989).

The greatest current threat to Phillip Island Hibiscus is the invasion of Phillip Island by African Olive (Olea europaea subsp. africana). African Olive competes with Phillip Island Hibiscus for water and nutrients, and can grow as dense thickets which block the expansion of Hibiscus populations (Groeneveld 1989; Sykes & Atkinson 1988).

Moth caterpillars (of the species Pectinophora scutigera and Asinoplaca cosmia) were found to inhabit the seed capsules of Phillip island Hibiscus and consume the seed. This does not threaten current individuals of Phillip Island Hibiscus but it reduces the ability of the species to produce viable seed to enable the recovery and growth of the population (Groeneveld 1989).

Soil erosion on Phillip Island reduces the ability of native vegetation to recolonise areas of the Island (Hyder Consulting 2008).

The Norfolk Island group sometimes experiences cyclones in the early months of the year (BoM 2008). The lack of vegetation on Phillip Island makes the island more vulnerable to erosion during periods of heavy run-off (Director of National Parks 2008; Mosley 2001).

A study of the biology of Phillip Island Hibiscus (Groeneveld 1989) found that there was no evidence that the adult population consisted of more than one genetic individual. If this is the case then the species is also at risk from extremely low levels of genetic diversity.

Control and eradication of weeds (including African Olive) is being undertaken on Phillip Island. The Park management will also undertake aerial layering of Phillip Island Hibiscus to induce vegetative reproduction and promote the species' recovery (Director of National Parks 2008).

Several of the priority actions listed in Mosley (2001) for the conservation of Norfolk Island would also be of benefit to Phillip Island Hibiscus. A study of current land use patterns and rehabilitation needs on the islands, and development of a plan for soil rehabilitation, is recommended. The restoration of native vegetation and the eradication of weeds are also listed as priority activities. Weed infestations have been reduced by removal of weeds and replanting with native species. Populations of African Olive can be controlled by chemical methods (Mosley 2001; Ziesing 1997).

Information on the biology of Phillip Island Hibiscus can be found in Groeneveld (1989). This information can be used to develop more targeted conservation practices.

Groeneveld (1989) conducted research on the conservation biology of Phillip Island Hibiscus.

Principles relevant to the conservation of Phillip Island Hibiscus can be found in:

  • Norfolk Island National Park and Norfolk Island Botanic Garden Management Plan 2008–2018 (Director of National Parks 2008).

  • World Wildlife Fund (Australia) project 65, conservation biology of the endangered species Hibiscus insularis: final report, January 1989 (Groeneveld 1989).

  • Island on the Brink: A Conservation Strategy for Norfolk Island (Mosley 2001).

  • Norfolk Island Weed Control Manual (Ziesing 1997).

  • The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

    Threat Class Threatening Species References
    Climate Change and Severe Weather:Droughts:Drought Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
    Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
    Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Olea europaea subsp. cuspidata (Olive, African Olive, Wild Olive) Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
    Species Stresses:Indirect Species Effects:Low genetic diversity and genetic inbreeding Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
    Species Stresses:Indirect Species Effects:Low numbers of individuals Commonwealth Listing Advice for Norfolk Island Flora - 11 Critically Endangered Species (Threatened Species Scientific Committee (TSSC), 2003o) [Listing Advice].

    Australian National Botanic Gardens (ANBG) (1988). Annual Report 1987-1988. [Online]. Department of the Arts, Sport, the Environment, Tourism and Territories. Available from: http://www.anbg.gov.au/anbg/annual-report/annual-report-1988.html.

    Bureau of Meteorology (BoM) (2008). Climate of Norfolk Island. [Online]. Commonwealth of Australia. Available from: http://www.bom.gov.au/weather/nsw/norfolk/climate.shtml.

    Department of the Environment and Heritage (DEH) (2003c). Norfolk Island Botanic Garden. [Online]. Available from: http://www.environment.gov.au/parks/norfolk/botanic.html.

    Director of National Parks (2008). Norfolk Island National Park and Norfolk Island Botanic Garden Management Plan 2008-2018. [Online]. Canberra. Available from: http://www.environment.gov.au/parks/publications/norfolk/pubs/management-plan.pdf.

    Director of National Parks (DNP) (2010). Norfolk Island Region Threatened Species Recovery Plan. [Online]. Canberra, Director of National Parks Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/norfolk-island.html.

    Green, P.S. (1994). Norfolk Island & Lord Howe Island. In: Flora of Australia. 49:1-681. Canberra, ACT: Australian Government Publishing Service.

    Groeneveld, K.M. (1989). World Wildlife Fund (Australia) project 65, conservation biology of the endangered species Hibiscus insularis: final report, January 1989. Commonwealth of Australia.

    Hyder Consulting (2008). The Impacts and Management Implications of Climate Change for the Australian Government's Protected Areas. [Online]. Department of Climate Change. Available from: http://www.greenhouse.gov.au/impacts/publications/pubs/protected-areas.pdf.

    Mosley, J.G. (2001). Island on the Brink: A Conservation Strategy for Norfolk Island. Norfolk Island Conservation Society, Melbourne, Victoria.

    Sykes, W.R. & I.A.E. Atkinson (1988). Rare and endangered plants of Norfolk Island. New Zealand: Botany Division, Department of Scientific and Industrial Research.

    Threatened Species Scientific Committee (TSSC) (2003o). Commonwealth Listing Advice for Norfolk Island Flora - 11 Critically Endangered Species. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/species/norfolk-island-flora-critically.html.

    Ziesing, P.D. (1997). Norfolk Island Weed Control Manual: for selected weeds occurring in Norfolk Island National Park. Environment Australia, Biodiversity Group, Parks Australia (South).

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    This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

    Citation: Department of the Environment (2014). Hibiscus insularis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sun, 31 Aug 2014 06:24:39 +1000.