New Zealand Journal of Botany abstracts
Coastal vegetation of small islands near Viti Levu and Ovalau, Fiji
SHAHINA A. GHAZANFAR*
GUNNAR KEPPEL
SHAFIYA KHAN
Department of Biology
School of Pure and Applied Sciences
University of the South Pacific
P.O. Box 1168
Suva, Fiji
*Present address: Department of Plant Sciences, University of Cambridge,
Downing Street, Cambridge CB2 3EA, UK.
Abstract Vegetation studies of nine small islands off the
east and south-east coasts of Viti Levu show that, for most islands, species
richness is low and represents between 21% and 44% of the total recorded
species for the islands. The majority of species on each island are dispersed
by sea (oceanic currents) or by animals (birds and bats). Wind dispersed
species are few on all islands. Fifteen species are common to five islands and
four and six species are common to all nine and eight islands, respectively.
The number of native species on each island is variable and ranges from 65% to
over 90%. Weedy species are mainly associated with cultivation and plantations.
Two major vegetation types are distinguished: the reef flat mangrove, and the
sandy beach vegetation. Both vegetation types show a pattern of zonation of
species from the beach inland. The vegetation of small sandy islands (up to
30 ha) that are relatively undisturbed consists mainly of coastal herbs,
shrubs, and trees. TWINSPAN classification showed that islands with similar
topography and substrate have similar plant communities. Our limited data
suggest that small sandy islands that lack inland topographical features (such
as hills) show an increase in species richness with an increase in island area.
However, since full floral surveys were not carried out for all islands, this
correlation may not stand true for the larger islands or for islands with
inland topographical features. We suggest that the major factors responsible
for the low species richness of small islands are the chance arrival of water
and/or bird dispersed seeds and a suitable habitat (substrate) for the
successful establishment of the species.
Keywords coastal vegetation; dispersal; drift disseminules;
Fiji; small islands; species richness; TWINSPAN classification; vegetation
zonation; western South Pacific islands
B00035
Received 21 August 2000; accepted 2 July 2001
New Zealand Journal of Botany, 2001, Vol. 39: 587-600
0028-825X/01/3904-0587 $7.00 (c) The Royal Society of New Zealand 2001
PDF file of entire paper: medium quality (923K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
