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Cycas Rumphii

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Cycas Rumphii 2007 NOMINATION – Cycas rumphii Section 1 – Conservation Assessment Information in this form is required for assessing species nominated as threatened under the EPBC Act. Answer all parts, in the table cell below the question, indicating when there is no information available. Taxonomy 1. What are the currently accepted scientific and common name/s for the species? Note any other scientific names that have been recently used. Cycas rumphii Miq. 2. Is this species conventionally accepted? If not, explain why. Is there any controversy on the taxonomy? Yes 3. Describe any cross-breeding with other species in the wild, indicating how frequently and where this occurs NA Legal status 4. What is the species’ current conservation status under Australian and State/Territory Government legislation? It is not currently listed as threatened under any relevant territory and state, or federal legislation. This species is not found in any other Australian state or territory. Description 5. Give a brief description of the species’: appearance, including size and/or weight, and sex and age variation if appropriate; social structure and dispersion (e.g. solitary/clumped/flocks) Cycas rumphii Miq. is a small evergreen tree up to 6 m tall that exists in six very small isolated sub- populations in closed forest, semi-deciduous forest, and deciduous scrub on Christmas Island. The entire population consists of twenty-four mature individuals, five juveniles, and nine seedlings. Male and female organs appear on separate plants in this species (dioecious). It is not common (globally) and very slow-growing (Du Puy 1987). C. rumphii largely occurs as isolated solitary individuals separated by large distances. Only ten individuals have been sexed and the ratio is 1:1. 6. Identify major studies on the species Du Puy D.J. (1987). The Distribution of Cycas rumphii Miq. On Christmas Is., Indian Ocean, and the particular importance of North-West Point in this Population. Correspondence to Government Conservator, ANPWS, Christmas Island. Du Puy D.J. (1988). Mapping of Christmas Island Native and Endemic Plants with Limited Distributions. Report for the Director of National Parks and Wildlife, Commonwealth of Australia. Du Puy D.J. (1993). Cycadaceae in George A.S., Orchard A.E., and Hewson H.J (Eds), Flora of Australia, Volume 50, Oceanic Islands 2, pp 529-530, Australian Government Publishing Service, Canberra. Hill K.D. (2004) The Cycad Pages – Cycas rumphii. Royal Botanic gardens Sydney. Retrieved from: http://plantnet.rbgsyd.gov.au/cgi-bin/cycadpg?taxname=Cycas+rumphii on 20 February 2006. International background (for species that are distributed both inside and outside Australia’s jurisdiction) 7. Describe the species’ global distribution This species was thought to be distributed throughout Malesia, the Philippines, and the Pacific islands as far as Fiji (Du Puy 1993). It is now understood that C. rumphii distribution is more restricted and centred on the Moluccan island group extending east into Indonesian Papua and a short way along the north coast of Papua New Guinea, and north to Sulawesi. In the west, it appears to extend to southern Borneo and north-eastern Java (Hill 2004). The Philippines have been removed from its occurrence distribution in Hill (2004). This species is relatively common in cultivation in Fiji and, to a lesser extent, Vanuatu. In both cases, female plants only are known, all of which have been vegetatively propagated from stem offsets. The cultivated plants in both of these countries show distinctively yellow new growth that is not typical of the species, which suggests that they are all from the one clone (Hill 2004). 8. Give an overview of the global population’s size, trends, threats and security of the species outside Australia The exact global population size is unknown. No data available. Vegetation clearing is the major threat to this species. Especially in those countries where human population density is high and vegetation clearing control is poor. 9. Explain the relationship between the Australian population and the global population, including: a. What percentage of the global population occurs in Australia; b. Is the Australian population distinct, geographically separate or does part or all of the population move in/out of Australia’s jurisdiction (give an overview; details in Movements section); c. Do global threats affect the Australian population? a. Unknown b. The Australian population is a distinct, or geographically separate population from all other populations in the region. Christmas Island is a remote oceanic island approximately 350 km from the next nearest population of C. rumphii in SE Asia. Almost all of the individuals on Christmas Island are at least 100 m above sea level, indicating their ancestors arrived on the island a very long time ago when sea levels where much different. There is only one individual currently near sea level (~20 m asl). This altitudinal distribution on island indicates that most individuals on the island have been geographically isolated for a very long time. c. Yes. There is continued pressure from the mining industry to clear more vegetation and mine phosphate ore bodies on Christmas Island. National context Distribution 10. Describe the species’ distribution in Australia and, if available, attach a map This species occurs only on Christmas Island and no other Australian state or territory. 11. What is the extent of occurrence (in km2) for the species (described in Attachment A); explain how it was calculated and datasets used a. What is the current extent of occurrence? b. What data is there to indicate past declines in extent of occurrence (if available, include data that indicates the percentage decline over the past 10 years or 3 generations whichever is longer)? c. What data is there to indicate future changes in extent of occurrence (if available, include data that indicates the percentage decline over 10 years or 3 generations whichever is longer (up to a maximum of 100 years in the future) where the time period is a continuous period that may include a component of the past)? a. Its extent of occurrence is approximately 108 km2 (10,800 ha). b. NA c. NA 12. What is the area of occupancy (in km2) for the species (described in Attachment A; explain how calculated and datasets that are used) a. What is the current area of occupancy? b. What data is there to indicate past declines in area of occupancy (if available, include data that indicates the percentage decline over the past 10 years or 3 generations whichever is longer)? c. What data is there to indicate future changes in area of occupancy (if available, include data that indicates the percentage decline over 10 years or 3 generations whichever is longer (up to a maximum of 100 years in the future) where the time period is a continuous period that may include a component of the past)? a. Its area of occupancy is approximately 11.6 x 10- 5 km2 (116 m2). b. There has been a very small decline (4 m2) in area of occupancy over the last 20 years due to the loss of one individual in the NE Point sub-population. c. NA 13. Is the species’ distribution severely fragmented? Why? Severely fragmented refers to the situation in which increased extinction risk to the taxon results from most individuals being found in small and relatively isolated subpopulations (in certain circumstances this may be inferred from habitat information). These small subpopulations may go extinct, with a reduced probability of recolonization. Yes. The entire population consists of twenty-four mature individuals, five juveniles, and nine seedlings. The population is currently severely fragmented into six sub-populations, spread far apart in isolated areas of the island (Figure 1 – located in a separate jpeg file). As well, almost all individuals within each sub-population on the island are spread far apart. The current distribution appears to be from an immigration event long ago when sea levels were much higher. This species occupies a very narrow altitudinal zone, around 200 m asl, and usually only occurs on the upper terrace lip, or plateau edge on the island. This zone C. rumphii currently occupies was probably the shoreline long ago when sea levels were much higher. It was during this period that its seeds, or broken trunks washed ashore and became established. There appears to have been very little dispersion on the island since this establishment event. 14. How many locations do you consider the species occurs in and why? The term 'location' defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the species present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a species is affected by more than one threatening event, location should be defined by considering the most serious plausible threat. The population is currently severely fragmented into six sub-populations, spread far apart in isolated areas of the island (Figure 1 – located in a separate jpeg file). There is between 2.8 and 17 km distance between each of the designated sub-populations. These sub-populations are: 1. Egeria Point sub-population: composed of 5 adults (sex is undetermined) and occupying 20 m2. 2. North-West Point sub-population: composed of 9 adults (two females, one male, and the rest sex is undetermined), 5 juveniles, 9 seedlings, and occupying 56 m2. 3. North-East Point sub-population: composed of 5 adults (3 males and 1 female, the sex is undetermined for the remainder) and occupying 20 m2. 4. Lily Beach sub-population: composed of 1 adult (male) and occupying 4 m2. 5. Margaret Knoll sub-population: composed of 3 adults (2 females, and the sex is undetermined for the remainder) and occupying 12 m2.
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