Plant Community Structure, Fire Disturbance, and Recovery in ...

Contributions to the Study of Biological Diversity Vol. 3
burned areas included Coussapoa asperifolia
Trécul, Aeschynomene sensitiva Sw., Heliconia
psittacorum L.f., Hibiscus bifurcatus Cav., and
Solanum stramoniifolium Jacq. as well as several
species of Amaranthaceae with tiny seeds that
may be wind blown at times.
The Beach community (38 species) was
primarily composed of species highly
specialized for the coastal environment, many
of which were not found in other vegetation
zones. That community clustered with the four
previous groups in part because of the presence
of individuals of mangrove species and
mangrove associates that were common in
neighboring habitats, including Laguncularia
racemosa, Avicennia germinans and
Conocarpus erectus. Those occurred
occasionally at the top of narrow beach ridges
and often on beach borders of coastal lagoons.
Some vines of the back beach were shared with
the burned areas, including Sarcostemma
clausum, Cissus verticillata, and Ipomoea
tiliacea (Willd.)Choisy; Vigna luteola
(Jacq.)Benth. was shared with Mixed
Freshwater swamp.
None of the Beach taxa were present in
either Quackal or Manicole communities. The
similarity of those two communities with the
other four Waini Peninsula communities was
based on only seven shared species. The Quackal
community as surveyed by van Andel was more
diverse (70 species) than any one of the Waini
Peninsula communities, probably reflecting low
soil salinity because of its distance from the
ocean (approximately 12 kilometers at the
Quackal plot). Van Andel considered the
Quackal vegetation type to grade into mangrove
swamp; the four species that it shared with the
Waini were Euterpe oleracea, Clusia palmicida,
Cassipourea guianensis Aubl., and
Calyptranthes sp., all shared with the Mixed
Freshwater swamp community, which may have
contributed to its clustering more closely than
the Manicole community with the Waini
communities.
The Manicole community was the richest
of the seven (96 species) and also the most
distant from coastal communities. The plot near
Assakata village on the Baramanni River was
approximately 17 kilometers from the Atlantic
Ocean. This community had a significant
41
overlap with the Quackal site, sharing 28
species. Of those, 18 are trees; the other shared
species were divided among shrubs, herbs, and
vines. The six species that those two sites shared
with the Waini Peninsula communities were
Monstera adansonii, Euterpe oleracea, Clusia
palmicida, Cassipourea guianensis,
Pterocarpus officinalis, and Peperomia glabella
(Sw.)A.Dietr.. Although the Manicole
community shared more species with the Waini
Peninsula communities than the Quackal
community shared with the Waini Peninsula,
those species were drawn from the Manicole
community’s higher number of species, and the
shared species were spread among several Waini
communities. Four species were shared with the
Mixed Freshwater community, the epiphyte
Peperomia was shared with the Riverine
Mangrove area, and the vine Monstera was
shared with the Coastal Mangrove community.
Calyptranthes sp. also occurred in Coastal
Mangrove, Mixed Freshwater, and Quackal
communities.
Of the 240 species from all seven sites, 189
(79%) were known from only one site; those
were divided among 26 from Burned areas (66%
of its species), 28 from the Beach community
( 76% of its species), 8 from Coastal Mangrove
swamp (42% of its species), 17 from Mixed
Freshwater swamp (50% of its species), 4 from
Riverine Mangrove swamp (50% of its species),
41 from Quackal swamp (59% of its species),
and 65 from Manicole swamp (68% of its
species).
Northwest District
A preliminary list of 1449 vascular plant
species from the Northwest District is given in
Appendix 3. Those species were approximately
22% of the known vascular flora of Guyana,
currently standing at 6,700 species (Boggan et
al. 1997; Hollowell et al. 2001). Additionally,
105 cultivated species, one alga and six mosses
were included on the list. Mosses and alga are
poorly collected and analyzed in the Northwest
District, as throughout the Guiana Shield, and
are included with the hope of encouraging future
research. A previous collections-based
compilation for the Northwest District listed 484
species of vascular plants (BDG 2001).
Collections made during these studies on the