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
The figures and estimates given here are those obtained from the literature (including the internet) and from discussions with a number of experts. In all cases sources are referenced.
Many of the figures are very loose, and no reliability can or should be put on them, especially with the lower groups of plants and animals, invertebrates, fungi, algae and protists. In most cases, I have supplied a maximum and minimum figure, and if one calculated an error based on these figures it would be in the order of about 25% for most groups.
Total figures for most groups are extremely inaccurate as one is adding error to error, and approximations to approximations. However, the figures supplied here are at least as good as those that have arisen from other sources.
Some major differences from previous estimates occur with the vascular plants where I have provided an estimate of about 20 500 species (including naturalised species) with 17 580 being native species. Previous estimates were in the order of 25 000. The estimate of 50 000 for total fungi species in Australia as suggested in the draft for the 2006 SOE report is, I believe, low, and this is backed up by several experts. Previous estimates of 250 000 may be on the high side, but it appears that a figure somewhere between about 160 000 and 250 000 is realistic. Another difference is in the estimated number of described species of vertebrates in the world, which I give to be around 61 000. This is about 11 000 greater than most previous estimates. The greatest area of unknown in this group is with the fishes.
I have added more detail for some groups than has generally been supplied, and this has helped in determining the numbers for the larger groupings (insects, arachnids, fungi, algae, protists, etc.).
No figures for endemism in Australia have been found for many groups, although some additional figures have been supplied. For the first time, a robust calculation for endemism in the flowering plants has been made, with estimates of 91% overall, and 91.7% for the Australian mainland determined.
Interestingly, for some of the better known groups (e.g. the vertebrates), it has been difficult to find estimates for the number of undescribed species, however for many of these groups (mammals, birds) it is likely to be quite low.