Survey of threatened plant species in South East Queensland biogeographical region queensland cra/rfa steering committee survey of threatened plant species in

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3.20 Macrozamia pauli-guilielmi W. Hill & F. Muell.

3.20.1 Summary

The distribution of M. pauli-guilielmi is restricted to an area between Bundaberg and Kin Kin. It covers a range of approximately 130 km and encompasses an area of occurrence of approximately 2400 km². It has been recorded from State Forest, National Park and freehold land. A total population of M. pauli-guilielmi was estimated to be between 10,000 and 14,000 individuals. The state forest sites are important to the conservation of the species because they represent a large proportion of the presently known populations. Current or perceived threats to the continued survival of M. pauli-guilielmi are considered to be loss of habitat, illegal removal of seeds, seedlings and mature plants from the wild and inappropriate fire regimes.

3.20.2 Species description and identification

The genus Macrozamia is placed in the family Zamiaceae. Macrozamia is an Australian endemic genus and consists of approximately 25 species (Jones 1993). It occurs in subtropical and temperate regions with the majority of species in south-eastern Queensland and eastern New South Wales.

Macrozamia pauli-guilielmi belongs to the section Parazamia. These are generally recognised by their subterranean trunk which have only a few leaves in the crown. The leaves are usually spirally twisted and the leaflets are all similar (ie. is the lower leaflets are not reduced to spine-like structures). The leaflets lack mucilage canals.
Macrozamia pauli-guilielmi has a nonbranching subterranean stem up to 20 cm diameter with 1 to 7 leaves protruding aboveground forming a sparse crown. Mature leaves are 0.5-1.2 m long and hairless except for the woolly base. Each leaf consists of 140-200 leaflets conspicuously arranged spirally along a central stalk. The leaflets are narrowly linear, measure 15-35 cm long by 2-4 mm wide, and are a dark, dull green above, yellowish underneath and shallowly concave in cross-section. The ends of the leaflets are spreading to weeping, the leaflet bases are white and conspicuously thickened. The plants reproduce by cones which are somewhat pineapple-like in appearance. Male and female cones develop on separate plants. Male cones are cylindrical, 10-20 cm long and 4-6 cm diameter. Female cones are ovoid to barrel-shaped, 8-15 cm long and 6-8 cm in diameter. Seeds are ovoid to oblong, 2-2.5 cm long, 1.5-2.0 cm in diameter and orange to red when ripe. For a more detailed description and illustration of this species refer to Jones (1993).
M. pauli-guilielmi is related to M. parcifolia and M. lomandroides. M. pauli-guilielmi can be distinguished from M. parcifolia by having generally broader, thicker-textured, leaflets, which are attached to the rhachis at a broader angle. M. pauli-guilielmi can be distinguished from M. lomandroides by having generally narrower, thinner textured leaflets which are generally weakly ascending to erect and which lack sharp teeth on the apex.

3.20.3 Current conservation status

Macrozamia pauli-guilielmi is presently listed on the schedule of the Queensland Nature Conservation Act 1992 as “endangered”. It is also listed on Schedule 1 Part 1 (endangered) of the Commonwealth Endangered Species Protection Act 1992. The species has not been assigned a national conservation status by ANZECC (1993).

3.20.4 Distribution and abundance

Details from Queensland Herbarium specimens of M. pauli-guilielmi are listed in Appendix 1.19. Altogether 27 herbarium specimens of M. pauli-guilielmi have been collected from approximately 14 localities in coastal areas from Bundaberg and Kin Kin. Eight of the records have insufficient information to relocate the collection sites. Another seven unvouchered localities have been noted on CORVEG data.

M. pauli-guilielmi was observed at 19 sites during the current survey within the previously recorded range. Six of the sites observed had not been previously recorded. Seventeen of the sites were examined in some detail. Appendix 2.7 lists the sites examined in the present survey with habitat data recorded for those sites. Detailed locality information is not given. This information is available on request from the Queensland Herbarium. Table 3.20.1 gives estimates of the area of occupancy and abundance of M. pauli-guilielmi at each site.
The distribution of M. pauli-guilielmi has a range of approximately 130 km and encompasses an area of occurrence of approximately 2400 km². As far as can be ascertained, the range of this species is natural and is not related to recent human activity. The total population of M. pauli-guilielmi was estimated to be between 10, 000 and 14, 000 individuals. Individual populations varied in size from 2 to at least 4300 individuals. Areas of occupancy varied from 0.01 to 8 hectares. Twenty of the twenty one sites recorded were in relatively undisturbed habitat.
Only a small proportion of the total population examined is within areas set aside for conservation of natural habitat. However, there are another 4 previously recorded sites that are within areas gazetted for conservation purposes. Currently there are no population details for these sites. Three sites occur in State Forest Scientific Areas. These were the largest populations examined during the current survey, consisting of 65 % of the total number of individuals observed. A number of small populations of M. pauli-guilielmi were observed within areas planted with exotic pines. The M. pauli-guilielmi individuals were mature and appeared to be remnants from the original vegetation prior to the pine plantation being planted (Plate 20 & 23). Other populations of M. pauli-guilielmi have recently been observed on freehold land in the vicinity of Tinana Creek (J. Brushe, pers. comm.).
All populations examined consisted of individuals that appear generally healthy.

3.20.5 Habitat

The sites are on gently undulating plains to low hills on hillcrests, very gently to moderately inclined hillslopes and levees with variable aspect and at elevations between 10-100 m above sea level. The soils are generally well drained, greyish yellow to very dark reddish brown, or brownish black, sands, loamy sands, sandy loam to light clay with pH 4.9-5.9 and occasionally stony. The geology is mostly sedimentary rocks from Duckinwilla Group, Kin Kin Beds, Burrum Coal Measures and Myrtle Creek Sandstones, and Quaternary alluviums.

The vegetation community is a layered very tall to tall open forest (Plate 22). The common canopy species are Corymbia intermedia, Eucalyptus racemosa, C. citriodora, Angophora leiocarpa and E. acmenoides. Other tree species occasionally present included: C. trachyphloia, E. crebra, E. major, E. fibrosa, E. umbra, E. microcorys, E. pilularis, E. siderophloia, E. tindaliae and Lophostemon confertus. The most frequent mid stratum species included: Allocasuarina littoralis, Banksia integrifolia subsp. compar, Alphitonia excelsa and Acacia aulacocarpa. Common shrub and ground cover species included: Themeda triandra, Acacia aulacocarpa, Entolasia stricta, Imperata cylindrica, Aristida spp., Acacia leiocalyx, Jacksonia scoparia, Lepidosperma laterale, Xanthorrhoea johnsonii and Xanthorrhoea latifolia. Other shrub and ground cover species present included: Acrotriche aggregata, Banksia oblongifolia, Cymbopogon refractus, Desmodium rhytidophyllum, Hakea plurinervia, Alphitonia excelsa, Cleistochloa subjuncea, Daviesia umbellulata, Geitonoplesium cymosum, Leptospermum trinervium, Lomatia silaifolia, Monotoca scoparia, Persoonia virgata, Daviesia ulicifolia, Gompholobium pinnatum and Lomandra multiflora.
Table 3.20.1. Estimated abundance, area of occupancy and land tenure for Macrozamia pauli-guilielmi sites.

Where abundance was estimated by transect sampling a mean value and lower and upper 95% confidence limits and are given. Populations obtained by direct counts or those visually estimated have no estimate of error associated with them. SA, SF = scientific area in state forest; SF = state forest; NP = national park; VCL = vacant crown land.

Site	Date surveyed	lower limit	Population mean	upper limit	Density	Land tenure	Area occupied (m²)
1	3 Oct 97		105			SF	30 000
2	3 Oct 97		2			SF	314
3	9 Oct 97		23			SF	314
4	9 Oct 97		106			NP	5 000
5	20 Oct 97		2			SF	100
6	27 Oct 97	4 321	5 120	5 919	0.06	SA, SF	80 000
7	22 Oct 97		158			SF	25 000
8	22 Oct 97		214			SF	2 500
9	22 Oct 97		10			SF	10 000
10	22 Oct 97	3 220	3 600	3 980	0.04	SF	100 000
11	22 Oct 97	909	1 224	1 539	0.05	SA, SF	24 000
12	24 Oct 97	1 832	1 950	2 068	0.13	SA, SF	15 000
13	24 Oct 97		42			SF	750
14	3 Oct 97		126			SF	20 000
15	3 Oct 97		20			SF	15 000
16	21 Oct 97		15			SF	78
17	31 Oct 97		105			VCL	1 023
		10 282	12 822	13 506			329 079

3.20.6 Life history and ecology

There have been no studies into the biology or autecology of M. pauli-guilielmi. The majority of the following information is extrapolated from our understanding of other cycads. However, it is also becoming increasingly clear that the reproductive processes and behaviour of different species within the same genus may differ considerably, so that information collected from one species cannot necessarily be extrapolated to another.

M. pauli-guilielmi can be easily propagated from seed and by slices from the trunk (Jones 1993). It is a dioecious, perennial plant that reproduces by sexually produced seeds. The longevity of the plants is unknown. Estimates of life span of other Macrozamia species range from 120 to 1500 years (Benson and McDougall 1993, Pate 1993). The coning period has not been recorded for M. pauli-guilielmi. However, it would be expected to produce cones in late spring to early summer.
The level of reproduction in cycads varies greatly from year to year. The factors controlling the level of reproduction are unknown. There are reports suggesting a cyclical nature in the level of reproductive episodes (Vorster 1995). Coning has been reported for M. pauli-guilielmi to be extremely irregular and seems to take place about every four to six years. It is suggested that variable rates of coning will also lead to variable rates of seedling recruitment. The level of survivorship from seed to adult is unknown. Survivorship of M. riedlei and M. communis has been reported by Connell and Ladd (1993). They observed that only 3-4 % of the seed produced survived to become adults with the greatest mortality occurring from seed germination to seedling stage.
Traditionally cycads have been thought to be wind-pollinated (Chamberlain 1935), but evidence has been mounting that most cycad species are in fact pollinated by insects, specifically by beetles (Tang 1987, Norstog and Fawcett 1995). Forster et al. (1994) reported a number of Coleoptera, Hymnenoptera and Thysanoptera in association with reproductive structures of Macrozamia species including M. pauli-guilielmi.
It is unknown when the seeds of M. pauli-guilielmi mature. However, based on other closely related species (M. lomandroides and M. parcifolia) it would be expected to be 3-6 months after coning. The seeds have a red to orange fleshy outer layer and fall from the cone at maturity. It has been reported that the fleshy outer layer attracts animals which feed on this fleshy tissue and secondarily disperse the seed. Possums, kangaroos, wallabies and rodents have been reported as dispersal agents for Macrozamia species (Jones 1993). However, from present field observations it would appear that most seeds are not dispersed far from the parent plant.
The seeds of most cycad species will not germinate immediately on maturity, for the embryo requires an after-ripening period (Jones 1993). M. communis and M. riedlei are reported to require 10-13 months before germination will occur (Ladd and Connell 1995). The seed of M. pauli-guilielmi requires approximately 6-12 months before it will germinate (Forster pers. comm.). The length of time that the seeds of M. pauli-guilielmi retain their viability is unknown. It is reported that under controlled storage conditions seeds of other Macrozamia species will retain their viability for many months (Jones 1993). Under field conditions it is suspected that seed would not stay viable for more than 6-12 months.
As germination occurs the micropylar end of the hard seed coat is ruptured by the emerging radicle, which turns down into the soil and grows rapidly. The greater part of the cotyledons remain inside the seed on the soil surface, absorbing all of the endosperm and transferring the food resources into the young root and developing underground stem of the seedling. Usually only one leaf appears initially at the soil surface some months after germination. The time from coning to the establishment of a juvenile with a single leaf is estimated to be 2 years. The length of time taken from seed germination to maturity is unknown. The time taken for cultivated cycads to reach maturity ranges from 2 to 30 years (Jones 1993).
From field observations it is suggested that seeds and the early stages of the seedling development are fire-sensitive (Plate 21). The time required before the seedling can tolerate fire is unknown. Mature plants are not greatly affected by fire. The destruction of the leaves above-ground occurs but the important growing tip is protected below ground level. There are some suggestions that some cycads may benefit from periodic exposure to fire (Zunckel 1995).

3.20.7 Threats

In the light of the field survey and from consultation with others, current or perceived threats to the continued survival of M. pauli-guilielmi are considered to be:

Loss of habitat: In the past large tracts of the habitat of M. pauli-guilielmi have been cleared for pine plantations and agriculture and to a lesser extent residential development. For those populations on freehold land and road reserves, the loss of habitat is a continuing issue.
Leaves and fruits of cycads are poisonous to domestic stock if ingested. Most graziers in the past have taken measures to eradicate cycads from areas where domestic stock graze. Those populations surviving in areas grazed by stock are still threatened by such land management.
Illegal removal of seeds, seedlings and mature plants from the wild: Cycads world-wide have become extremely desirable plants to collect. The proximity of known populations to tracks and roads makes them potentially threatened by illegal removal if the locations of the populations are generally known.
Inappropriate fire regime: Mature Macrozamias generally cope very well with fire and as pointed out earlier may benefit from periodic exposure to fire. However, fire can certainly affect the recruitment of new individuals because the seeds and young seedlings of M. pauli-guilielmi are fire-sensitive. Too frequent a fire regime would certainly lead to a gradual decline in the population as mature plants became senescent and there was a lack of recruitment of new plants. The impact of present Department of Primary Industries, Forestry fire management on the ability of M. pauli-guilielmi to maintain a sustainable population level is unknown. The consequences of repeated burning over a long time on the invertebrate pollinators are also not known.

3.20.8 Management, Research and Conservation Measures

In the long term the populations within areas currently planted with exotic pines are unlikely to survive. Prior to replanting of the next crop of pine the ground is ripped and then mounded. It is suspected that a large proportion of the plants would not survive this site preparation. Investigations should be undertaken into the possibility of salvaging these individuals.

There is little information available on the role of fire in the ecology and reproductive biology of M. pauli-guilielmi. This needs to be understood if successful management techniques are to be developed for conservation of the species in the wild. Research into the effect of fire on coning and seedling survival is required.
The protection of the remaining populations of M. pauli-guilielmi in natural vegetation in the state forest lands that are not presently within State Forest Scientific Areas should be pursued.
To reduce the illegal removal of plants and propagules of M. pauli-guilielmi from the wild, locality information of populations should not be supplied to persons who do not have appropriate permits from Department of Environment and Department of Primary Industries. Current legislation to prevent illegal collection of threatened species from the wild needs to be enforced.
Macrozamia pauli-guilielmi when assessed against the IUCN (1994) criteria for threatened wildlife falls into the category of Vulnerable, ie. is facing a high risk of extinction in the wild in the near future, as defined by criteria D.2. Its population is characterised by an acute restriction in its area of occupancy (typically less than 100 km²). The present status of Endangered for M. pauli-guilielmi should be reconsidered in the light of the present data available.

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