Species richness (plants and algae)

[Karen L. Wilson]

Since this is likely to be of interest to others (and I would also be interested
in comments from others as to the accuracy of my figures), I am replying to
TAXACOM rather than direct to Matt. I have been putting together such figures
on species numbers for a Diversitas report, with the help of other botanists.
The estimates (rounded off, obviously) we have come up with are as follows:

1. total number of vascular and non-vascular plant species worldwide - 302,000,
based on the figures below (i.e. excluding all algae).

2. estimated number of bryophytes species worldwide - 16,000 described plus up
to 3,000 undescribed spp
2a. number of hepatic species - 6,000 (i.e. total; not sure of proportion
undescribed)
2b number of moss species - 10,000 described plus up to c. 3,000 undescribed spp
2c number of hornworts - 100

3. estimated number of ferns & fern allies worldwide - 11,000 described + 1,000
undescribed spp

4. number of gymnosperm species worldwide - because this is not a 'natural'
group, we have broken this up into conifers (650 spp), cycads (100), Ginkgo (1),
Gnetales (70).

5. number of angiosperm species worldwide - 240,000 described + 30,000
undescribed spp
5a number of monocots  about 25% of that number
5b number of dicots - about 75% of that number

I would be pleased to hear any other suggestions from TAXACOMers, including
figures for each continental mass - I won't post the detailed figures here but I
am happy to send such figures as I have to anyone interested, especially if they
can help me refine them.

With advice from phycologists and after consulting the literature, I have also
been putting together estimated numbers of algal species. This is even more
difficult, given the relatively poor state of knowledge for many of those
groups. I have been subdividing the total into marine and freshwater, but our
figures so far are very incomplete for the different groups, continents and
ocean basins. Any help that can be given would be much appreciated!

If people send their messages direct to me, I will post a summary to TAXACOM.

Karen Wilson

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          Karen L. Wilson
          Royal Botanic Gardens             E-mail: karen at rbgsyd.gov.au
          Mrs Macquaries Road               Fax: 61-2-9251.7231
          SYDNEY   NSW 2000, AUSTRALIA      Phone: 61-2-9231.8137

______________________________ Reply Separator _________________________________
Subject: species richness
Author:  <m.vonkonrat at AUCKLAND.AC.NZ> at mailgate
Date:    28/3/99 20:20
Dear all,
Does anyone know the latest figures  or where I could obtain them, for the
following information:
1. total number of vascular and non-vascular plant species worldwide
2. estimated number of bryophytes species worldwide
        2a. number of hepatic species
..
----------------------
matt von konrat
m.vonkonrat at auckland.ac.nz