Biodiversity and Conservation 8: 977–1004, 1999.
© 1999 Kluwer Academic Publishers. Printed in the Netherlands.
Biodiversity of palm fungi in the tropics:
are global fungal diversity estimates realistic?
JANE FRÖHLICH
1
and KEVIN D. HYDE
2,∗
1
Landcare Research, Private Bag 92170, Auckland, New Zealand;
2
Fungal Diversity Research Project,
Department of Ecology and Biodiversity, The University of Hong Kong, Pokfulam Road, Hong Kong;
∗
Author for correspondence (fax: (852) 25598954; e-mail: kdhyde@hkucc.hku.hk)
Received 13 August 1998; accepted in revised form 1 December 1998
Abstract. Two questions are addressed: ‘How many species of fungi can occur on a single host palm?’ and
‘What are the implications of this for global estimates of fungal diversity?’ Fungal diversity estimates found
in the literature are reviewed. Data on the numbers of fungi occurring on the above-ground tissues of six
individual palms in the genus Licuala in Australia and Brunei Darussalam (Borneo) are provided. A total
of 189 species of fungi were isolated and/or collected from the six palms. In addition, 53 ‘morphospecies’
of mycelia sterilia were isolated, giving a total of 242 taxa from the 2672 isolates/collections made. The
three palms in Australia (sampled once) yielded 100 species (each palm supporting an average of 54.7
taxa), while the three palms in Brunei Darussalam (sampled three times) yielded 172 species in total
(approximately 111.3 taxa each). The magnitude of global fungal diversity, estimated at 1.5 million species,
is discussed. Our results indicate that 33 to 1 would be a more accurate estimate (than 5.7 to 1) of the ratio
of host specific fungal to palm species in the tropics. We therefore propose that global estimates of fungal
diversity, based on temperate studies, require revision upwards.
Key words: mycota, Palmae, tropical rainforest
Introduction
Historical biodiversity estimates
Indiscussionsoffungaldiversity,the term ‘fungi’isusuallyused inits broadestsense;
i.e. to include all organisms studied by mycologists in the kingdoms Protoctista and
Eumycota. One of the earliest biologists to realise that the fungi were among the
most speciose groups of organisms was Fries (1825), who compared the diversity of
fungi with that of insects. Early estimates of the number of fungal species world wide
varied from 100000 (Bisby and Ainsworth 1943) to approximately the same as the
number of vascular plant species, i.e. 250 000 to 270 000 (Martin 1951). More recent
estimates suggest that the number of species may be an order of magnitude greater,
about 1.5 million (Hawksworth 1991).