Australian Biological Resources Study
A.D.Chapman
Australian Biodiversity Information Services, Toowoomba, Australia
A Report for the Department of the Environment and Heritage, September 2005
ISBN (printed) 978 0 642 56849 6
ISBN (online) 978 0 642 56850 2
Estimates for the Bryophyta are complicated somewhat by the definition of the group (i.e. Phylum or Division). In some cases the category is circumscribed to include only the mosses, in others to include the hornworts, and liverworts, etc; hence the discrepancy in some of the cited numbers. Here, I am using it in the broader sense to include the true mosses (Bryophyta/Bryopsida), the hornworts (Anthocerophyta/Anthocerotopsida) and liverworts (Hepatophyta/Marchantiopsida).
Estimates of the number of described species vary from 15 000 (Hallingbäck and Hodgetts 2000, IUCN 2004) to 23 000 (Helzner 2002). The University of Auckland (n.dat.) provides figures of c. 10 000 for the mosses, 6 500–7 000 for liverworts and c. 100 for the hornworts, giving an estimate of 16 600–17 100 species in total. Other estimates for mosses vary from 9 500 to 12 000 with the figure of 10 000 usually accepted (e.g. Groombridge and Jenkins 2002). Groombridge and Jenkins (loc. cit.) also provide estimates of 6 000 for liverworts (Hepatophyta), and 600 for the hornworts (Anthocerophyta). De Luna et al. (2003) as part of The Tree of Life project also provided an estimate for mosses of 10 000 species. Numbers of c. 10 000 for mosses, c. 6 500 for liverworts and c. 100 for hornworts have been accepted here, providing a total of c. 16 600 species.
I have not found a published estimate for the total number of species, however Groombridge and Jenkins (2002) suggested that the proportion of the groups known is moderate to high for the Bryophyta and moderate for both the Anthocerophyta and Hepatophyta. Christine Cargill (pers. comm.105) provided a figure of 20 000–25 000, however, Patrick McCarthy (pers. comm.106) suggested that the figure was more likely at the lower end of this range.
There are 983 species of moss (Neils Klazenga pers. comm.107), and 869 accepted species of liverworts and hornworts (McCarthy 2003). There are an estimated 250 endemic species of moss 108 (25.4% endemism) and between 200 and 250 endemic species of liverworts and hornworts 109 (23–28% endemism). DEH (2005) estimated the number of Australian species described at around 1 950, with about 2 500 species in total. The DEH figure would appear to be a little high.
There is one threatened species listed for Australia (DEH 2005b).
| World Described minimum | World Described maximum | World Accepted | World Estimate | Australia Described | Australia Described % of World Described | Australia Estimate | Australia Endemic | World Threatened110 | Australia Threatened111 | Australia Threatened % of World Threatened |
| 15 000 | 23 000 | 16 600 | ~22 000 | 1 852 | 11.2% | ~2 200 | 25% | 80 (0.5%) | 1 (0.05%) | 1.3% |
Ferns and fern allies here have been taken to include the true ferns (Filicinophyta/Polypodiopsida), the club mosses, spike mosses, quillworts (Lycophyta, Lycopodiophta/Lycopodiopsida, Selaginellopsida, Isoetopsida), spike horsetails (Sphenophyta/Sphenopsida) and whisk ferns (Psilophyta/Psilopsida) as recognised by various authors. Estimates for the numbers of described taxa include 13 025 (Groombridge and Jenkins 2002), who report numbers of c. 1 000 Lycophyta, c. 12 000 Filicinophyta, 10 Psilophyta and 15 Sphenophyta. This is also the number accepted by the IUCN (2004). Other estimates include 12 838 in the Checklist of Ferns of the World (Hassler and Swale 2002). Interestingly, they also estimate a total number of species as between 10 614 and 12 001 which is less than the described number of species they include in the Checklist. Previous estimates from Swale (2000) were for between 10 000 and 15 000 species. Peter Bostock (pers. comm.112) suggests that there could be somewhere between 15 000 and 20 000 species worldwide, however there are complications with hybridisation, and with species on islands that may or may not be conspecific with mainland species (i.e. vicariant species complex). I have accepted the figures of Hassler and Swale (2002) for known species, and an estimate of 15 000 based on the figures of Swale (2000) and Bostock (ibid.).
Figures for Australia include 391 Filicinophyta, 47 Lycophyta (including Selaginellopsida and Isoetopsida), and eight Psilophyta (ABRS 1998). In addition there are about 36 naturalised species. It is estimated that about 40% are endemic. Bostock (pers. comm.) suggests a figure of about 500 as the total fern flora for Australia.
There are 35 listed threatened species in Australia (DEH 2005b).
| World Described minimum | World Described maximum | World Accepted | World Estimate | Australia Described | Australia Described % of World Described | Australia Estimate | Australia Endemic | World Threatened113 | Australia Threatened114 | Australia Threatened % of World Threatened |
| 12 000 | 15 000 | 12 838 | 15 000 | 446 | 3.5% | ~500 | 40% | 140 (1%) | 35 (7.9%) | 25% |
Estimates for the number of described species in the world are about 630 Coniferophyta, 145 Cycadophyta, about 70 Gnetophyta and one Gingkophyta (Groombridge and Jenkins 2002). The IUCN (2004) reported a total of 980 species of Gymnosperms based on Donaldson (2003), Farjon (2001) and Mabberley (1997) which is a higher figure than those provided by Groombridge and Jenkins (2002). Land Plants On-line115 list around 600 species of Coniferophyta, whereas Hill (1998c, 2004) estimates that there about 250 known species of Cycad and c. 600 species of Pinophyta (Hill 1998b), 71 species of Gnetophya and one of Gingkophyta (Hill 1998a). These figures seem to indicate a total figure for Gymnosperms of about 950 (600 conifers, 250 cycads, 71 gnetophytes and one gingko). No estimates for the total number of Gymnosperms has been found, but it would probably be in the order of 1 000 species.
Figures for the Australian Gymnosperms include: Coniferophyta 44 (39 of which are endemic) (Hill 1998b); and Cycadophyta 69 (all of which are endemic) (Hill 1998c). Groombridge and Jenkins (2002) provided an estimate of 90 species for Australia, which is too low. No estimate of the total gymnosperm flora of Australia has been found, but it is unlikely to be much higher than the presently known figure.
There are 20 listed threatened species in Australia and one threatened subspecies (DEH 2005b).
| World Described minimum | World Described maximum | World Accepted | World Estimate | Australia Described | Australia Described % of World Described | Australia Estimate | Australia Endemic | World Threatened116 | Australia Threatened117 | Australia Threatened % of World Threatened |
| 846 | 980 | ~930 | ~1 000 | 113 | 12.2% | 113 | 96% | 305 (32%) | 20 (17.7%) | 6.6% |
Estimates for the number of described species of flowering plants in the world vary from 248 000 (Tangley 1997), 258 650 (Thorne 2002, IUCN 2004) to about 270 000 (Groombridge and Jenkins 2002). The IUCN (2004) and Groombridge and Jenkins (2002) estimated that the total flora was about 320 000 species. In 2001, Govaerts (Govaerts 2002) estimated that there were 422 127 species of flowering plants based on the first volumes of his World Checklist of Seed Plants, whereas Bramwell (2002), using different methods, estimated a total of 421 968 species. Bramwell suggested that ‘it would seem safe to say that the world has about 422 000 species of flowering plants’.
Australian figures for flowering plants vary from 15 638 (Walter & Gillett 1998, Williams 2001, Groombridge and Jenkins 2002), 18 821 (Sjöström & Gross submitted) to about 20 000 (DEH in prep.). Sjöström & Gross, loc. cit., reported a total of 18 821 species including 1 997 introduced species, thus giving a total of 16 824 native species. A count carried out as part of this report produced a figure of 17 023 native species on the Australian mainland and 17 281 when the offshore islands were included. Confusion does arise with knowing whether some species are introduced or native, and What’s Its Name (ANH et al. 2005) includes a number of species where more than one name (synonyms) is listed as current and it does include some extra-Australian species (especially in the Orchidaceae). I do, however, believe that the figure cited here of 17 281 (±0.5%) is realistic. What’s Its Name (loc. cit.) also lists around 298 species as formulae names or manuscript names—i.e. known but as yet unpublished species, and over 2 100 introduced and naturalised species. When these are included, the total number of native species is 17 580 with 19 680 total native and naturalised species.
The estimates of 15 638 as cited by several authors, appear to have all been sourced from the Australian National Botanic Gardens (ANBG 2004) which refers to figures estimated in 1990. I expect that other estimates of around 20 000 include as many as 3 000 introduced species. Estimates for the total number of Australian flowering plants species vary from 20 000 to 25 000 (DEH in prep.), but again I suspect that these figures include introduced species, and I would be reluctant to include a figure greater than 19 000–21 000 for native species.
Estimates for endemism vary from about 85% (Williams 2001), 90% (Groombridge and Jenkins 2002) to 92% (Wong 1999). Groombridge and Jenkins (2002) cited a figure of 14 074 endemic species out of their total of 15 638 giving an endemism of 89%. In 1998, Conservation International provided a figure of 14 458 endemic species (Wong 1999). Given a total number of 17 281 species accepted here, that would indicate percentage endemism of approximately 85. A count carried out for this project using the Australian Plant Census (CHAH 2005), What’s Its Name (ANH et al. 2005), published hard-copy and on-line volumes of the Flora of Australia (ABRS 2005d), the Australian Plant Name Index (Chapman 1991) and the Census of Australian Vascular Plants (Hnatiuk 1990) produced a figure of 91.7% endemism for mainland Australia and 91% once the offshore island floras are added in118. The total number of endemic species needs to be recalculated once the new Australian Plant Census of Australian vascular plant species is completed.
There are 1 139 listed threatened species of flowering plant in Australia, of which 95 are undescribed. There are also 106 listed infraspecific taxa of which three are undescribed (DEH 2005b).
| World Described minimum | World Described maximum | World Accepted | World Estimate | Australia Described119 | Australia Described % of World Described | Australia Estimate | Australia Endemic | World Threatened120 | Australia Threatened121 | Australia Threatened % of World Threatened |
| 235 000 | 425 000 | 258 650 | ~422 000 | 17 580 | 6.8% | ~19 000–21 000 | 91% | 7 796 (3.0%) | 1 139 (6.5%) | 14.6% |