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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3.19 Macrozamia parcifolia P.I. Forst. & D.L. Jones

3.19.1 Summary

The distribution of M. parcifolia is restricted to an area in the Maryborough - Biggenden district. It covers a range of approximately 60 km and encompasses an area of occurrence of approximately 1500 km². It has been recorded from State Forest, National Park, freehold land and road verges. A total population of M. parcifolia was estimated to be between 16,500 and 18,000 individuals. The state forest sites are important to the conservation of the species because they represent the largest proportion of the presently known populations. Current or perceived threats to the continued survival of M. parcifolia are considered to be illegal removal of seeds, seedlings and mature plants from the wild, loss of habitat and inappropriate fire regimes.

3.19.2 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 parcifolia 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. the lower leaflets are not reduced to spine-like structures). The leaflets lack mucilage canals.
Macrozamia parcifolia has a nonbranching subterranean stem 10-20 cm diameter with 1 to 4 leaves protruding aboveground forming a sparse crown. Mature leaves are 65-95 cm long and hairless except for the woolly base. Each leaf consists of numerous leaflets arranged spirally along a central stalk. The stalk is dark green with greenish-white markings between the bases of the leaflets. The very narrow linear leaflets are 15-40 cm long by 1-3 mm wide, dark green above, bright green beneath and are strongly concave in cross-section. The leaflet bases are greenish-white and slightly 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, 7-14 cm long and 2.5-4 cm diameter. Female cones are ovoid to ovoid-cylindrical, 8-14 cm long and 4-6 cm in diameter. Seeds are ovoid to oblong, 1.7-2.5 cm long, 1.5-2.0 cm in diameter and orange to red when ripe. For a more detailed description of this species refer to (Jones & Forster 1994) (see Plate 16).
M. parcifolia is related to M. pauli-guilielmi but can be distinguished from this species by having generally narrower, thinner-textured, darker green leaflets which are attached to the rhachis at a steeper angle. In addition the leaves of M. parcifolia have an untidy and wispy appearance.

3.19.3 Current conservation status

Macrozamia parcifolia is presently listed under the name Macrozamia sp. (Biggenden P.I. Forster+ PIF12301B) on the schedule of the Queensland Nature Conservation Act 1992 as “vulnerable wildlife”. It is also listed on Schedule 1 Part 2 (vulnerable) of the Commonwealth Endangered Species Protection Act 1992. The species has not been assigned a national conservation status by ANZECC (1993).

3.19.4 Distribution and abundance

Details from Queensland Herbarium specimens of M. parcifolia are listed in Appendix 1.18. A total of 14 specimens of M. parcifolia have been collected from approximately 7 localities in the Biggenden district.

The distribution of M. parcifolia has a range of approximately 60 km and encompasses an area of occurrence of approximately 1500 km². As far as can be ascertained, the range of this species is natural and is not related to recent human activity. M. parcifolia was observed at 23 sites during the current survey within the previously recorded range. Twenty were located within state forests, one within a conservation reserve, one on freehold land, and one on road reserve and freehold land. Another population has been reported on freehold land but was not examined during the current survey (C. Lancaster pers. comm.). Nineteen of the sites were examined in some detail including 4 of the 7 previously known localities. Appendix 2.6 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 3.19.1 gives estimates of the area and abundance of M. parcifolia at each site examined in detail. Three of the previously recorded localities were searched for unsuccessfully. Another four new sites were vouchered but not recorded in detail due to insufficient time available. All four sites are within state forests.
The total population of M. parcifolia was estimated to be between 16500 and 18000 individuals. Individual populations varied in size from 5 to at least 3600 individuals. Areas of occupancy varied from 0.4 to 8 hectares. Only a small proportion (4 %) of the total population examined is within lands set aside for conservation of natural habitat. The majority of the population (79 %) observed is within state forests. Twelve of the 20 sites recorded in state forest areas have had timber harvesting carried out in the surrounding compartment at least once since 1956.
All populations examined consisted of individuals that appear generally healthy.

3.19.5 Habitat

The sites are on undulating to steep low hills on hillcrests and very gently to moderately inclined hillslopes with variable aspect and at elevations between 100-220 m above sea level. The soils are generally well drained, brown, dull reddish brown to brownish black, loamy sand, sandy loam to light clay with pH 4.8-6.0 and occasionally stony. The geology is mostly the Brooweena formation with sedimentary rocks of quartzose to sublabile sandstone, conglomerate, siltstone, mudstone and shale.

The vegetation community is a layered very tall to tall open forest. The common canopy species are Eucalyptus acmenoides, Corymbia citriodora, Angophora leiocarpa, E. fibrosa, C. trachyphloia and E. crebra. Other tree species occasionally present included
Table 3.19.1. Estimated abundance, area of occupancy and land tenure for Macrozamia parcifolia 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. SF = state forest; RR = road reserve; F = freehold; NP = national park.

Site	Date sampled	lower limit	Population mean	upper limit	Density	Land tenure	Area occupied (m²)
1	30 Sep 97		269			SF	45 000
2	28 Sep 97	298	310	322	0.03	SF	10 000
3	2 Oct 97	1 090	1 200	1 310	0.12	SF	10 000
4	2 Oct 97	2 919	3 075	3 231	0.10	SF	30 000
5	2 Oct 97		5			SF	2 500
8	2 Oct 97	1 226	1 320	1414	0.13	SF	10 000
9	1 Oct 97		65			SF	4 800
10	1 Oct 97		9			SF	400
11	23 Oct 97	3 276	3 360	3 444	0.04	SF	80 000
12	28 Oct 97	3 675	3 760	3 845	0.09	SF	40 000
14	30 Sep 97		43			SF	40 000
16	2 Oct 97		42			SF	10 000
17	2 Oct 97		194			SF	10 000
18	2 Oct 97		9			SF	2 500
19	2 Oct 97		29			SF	10 000
20	3 Oct 97		25			SF	2 000
21	30 Sep 97		22			RR;F	2 400
22	23 Oct 97	2 625	2 780	2 935	0.14	F	20 000
23	23 Oct 97	721	754	786	0.10	NP	7 850
		16 542	17 280	17 999			337 450

Eucalyptus exserta, E. major, Lophostemon confertus, Corymbia intermedia and E. longirostrata. The most frequent mid stratum species included: Lophostemon confertus, Acacia aulacocarpa and Eucalyptus saplings. Common shrub and ground cover species included: Acacia leiocalyx, Lophostemon confertus, Xanthorrhoea latifolia, Acacia aulacocarpa, Aristida spp., Jacksonia scoparia, Acrotriche aggregata, Lepidosperma laterale, Themeda triandra, Jacksonia scoparia, Cymbopogon refractus and Hardenbergia violacea. Other shrub and ground cover species present included: Chrysocephalum apiculatum, Acacia complanata, Cleistochloa subjuncea, Imperata cylindrica, Acacia leiocalyx, Entolasia stricta, Dianella revoluta, Lantana camara*, Pultenaea spinosa, Acacia bancroftii, Acacia falcata, Acacia fimbriata, Acacia penninervis subsp. penninervis, Alphitonia excelsa, Persoonia sericea, Podolobium scandens, Sida subspicata, Eragrostis brownii, Macrozamia mountperriensis, Acacia conferta, Goodenia rotundifolia and Lomandra longifolia.

3.19.6 Life history and ecology

There have been no studies into the biology or autecology of M. parcifolia. 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. parcifolia 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). Coning has been recorded occurring in M. parcifolia from October to January (Jones and Forster 1994). From the present survey work undertaken in October 1997 the percentage of plants coning in the samples range from 1 to 19 % with a mean of 3.9 % over all samples (Table 3.19.2). Twice as many plants were observed with male cones than female cones. Similar levels of male-biased coning events and low levels of participation in given reproductive episodes have been reported in other species of Macrozamia (Ornduff 1993).
The level of reproduction 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 (Jones 1993, Vorster 1995). 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.
Table 3.19.2. demographic and coning data for selected sample sites of Macrozamia parcifolia.

Site	Total adults	% adults	juveniles	% juveniles	No. of plants with male cones	No. of plants with female cones	% adults coning	Total plants
1	238	88.5	31	11.5	5	0	1.86	269
2	31	100.0	0	0.0	5	1	19.35	31
3	120	50.0	120	50.0	1	1	0.83	240
8	133	50.4	131	49.6	8	5	4.92	264
12	82	87.2	12	12.8	1	0	1.06	94
22	349	83.5	69	16.5	14	10	5.74	418
Totals	953	72.4	363	27.6	34	17	3.88	1 316

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.

Seeds of M. parcifolia mature from February to April (Jones and Forster 1994). 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. parcifolia requires approximately 6-12 months before it will germinate (Forster pers. comm.). The length of time that the seeds of M. parcifolia 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. 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). It was observed during the present survey that in recently burnt areas recently burnt M. parcifolia was quick to recover and was usually the first species in the habitat to produce new growth after fire. It would appear that if the growing apex is not killed by fire or destroyed by physical disturbance then M. parcifolia can regenerate (Plate 18 & 19).

3.19.7 Threats

There is no quantitative data to indicate that populations of M. parcifolia are presently declining. However, in the light of the field survey and from consultation with others, current or perceived threats to the continued survival of M. parcifolia are considered to be:

Loss of habitat: There can be no doubt that past habitat alienation, for agriculture and road development in the species’ narrow geographical range has led to a decline in populations in the past. 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 practices.
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. parcifolia 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. parcifolia 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.

3.19.8 Management, Research and Conservation Measures

The majority of the presently known population is within State Forest lands which make this area important in the conservation of the species. Appropriate management guidelines should be prepared in relation to areas within State Forest. Individual mature plants can survive habitat disturbance caused by timber harvesting, however the long term impact of timber harvesting in the habitat on this species is unknown. Research is required into the effects of current management of the habitat. Fire is an important management tool in forested areas. There is little information available on the role of fire in the ecology and reproductive biology on of M. parcifolia. 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.

To reduce the illegal removal of plants and propagules of M. parcifolia 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.
M. parcifolia 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 medium-term 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 Vulnerable for M. parcifolia is considered appropriate.

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