american samoa - University of Hawaii at Manoa

When undisturbed, the floor of the forest is
relatively open, and is usually dominated by shade-
tolcrant ferns. At Amalau, the dominant ground
cover species was the fern Lomagramma cordi-
pinna, with lesser amounts of Arthropteris repens
(mostly on rocks and tree trunks) and Tectaria
sfmrrisii, also ferns. Other terrestrial ferns present
include Asplenium nidus (bird's-nest fern,
laugapapa), Asplenium polyodon, Pteris tripartita,
Angiopteris evecta (king fern, nase), Bolbitis palu-
sfris, Phymatosorus scolopendria (lau magamaga),
Pneumatopteris bryanii, and Diplazium proliferum.
This is very similar to the previously mentioned
Aiga plot sampled in 1976, where Lomagramma
was the dominant, followed by Asplenium nidus
(Whistler 1980).
Trunk climbers are fairly common in this
community, especially the aroid Epipremnum
pinnatum and the previously mentioned ferns
Lomagramma cordipinna and Arthropteris
repens, which are usually restricted to the lower
trunks. Also common in some places is Piper
graeffei. Similar results were recorded at Aiga,
where Epipremnum and Piper were the two
dominant species. Lianas are not very common in
this community, at least at Amalau. The most
typical species are Gynochtodes epiphytica, Hoya
pottsii, and Alyxia bracteolosa (lau maile).
Epiphytes are not very abundant, at least when
compared to montane forest. The most common
species is Asplenium nidus, as it was at Aiga; also
present are Phymafosorus scolopendria, Davallia
.solids (laugasese), Davallia epiphylla (laugasese),
Nephrolepis biserrata, and Antrophyum planta-
gineum, all of which are ferns, and Dendrobium
dacfylodes, which is an orchid.
b. Coastal Lowland Forest - This is the lowland
forest that occurs on ridges from inland of the
littoral forest to about 200 m elevation (Fig. 19). It
is virtually the same thing as the "'au'auli coastal
forest" recognized in American Samoa (Whistler
1980) and "Diospyros coastal forest" described from
the offshore islet of 'Upolu, Western Samoa
(Whistler 1983), but was not reported in the park
area on Ta'u (Whistler l992b). It is characterized by
species that are found on lower ridges and by the
presence of a some of littoral species. It is some-
what transitional between the forest of interior
ridges and littoral forest dominated by Barringtonia
asiatica (futu). The boundaries between this forest
and the other two are not distinct, especially since
Barringtonia can be found at over 200 m elevation
(and occasional trees at much higher elevations, but
possibly planted there).
Two plots, nos. 1 and 2 in Appendix B, were
sampled in this forest. Plot 2 was at Matapai Point
(shown on most maps as "Matape") at the northeast
comer of the park (and perhaps just a little outside
of the currently proposed boundaries) at about 50 m
elevation, the other on Sauma Ridge just to the west
of Amalau Valley at 185 m. These two are some-
what heterogeneous, because they probably
represent the lower and upper limits of this type of
lowland forest. The lower plot had some littoral
forest elements, such as Terminalia catappa (talie),
and the upper had some elements from the higher
elevation ridge forest.
By combining the data from the two plots, the
following trees were shown to be the typical species
(excluding secondary forest species): Diospyros
samoensis ('au'auli) with an average relative
dominance of 18%, Garugafloribunda (vivao) with
17%, Barringtonia asiatica with 12%, Planchonella
garberi ('ala'a) with lo%, Planchonella grayana
with 5%, Guettarda speciosa (puapua) with 3%,
and Syzygium clusiifolium (asi vai) with 1%. Three
other species characteristic of this vegetation are
Diospyros elliptica ('anume), Sterculia fanaiho
(fana'io), and Syzygium dealatum (asi vai?). A
dominance of the Syzygium and the Diospyros
species is probably the best indicator of this type of
vegetation.
The forest floor is relatively open, since it is
much drier than the above described lowland forest
of alluvial valleys. The dominant species is
probably Asplenium nidus (bird's- nest fern,
laugapa). Also sometimes common are the ferns
Phymatosorus scolopendria (lau maga maga),
Davallia solida (laugasese), and Tectaria stearnsii.
In sunny places where the canopy is broken, weeds
such as Nephrolepis hirsutula (sword fern, vao
tuaniu), may become common. Seedlings are often
abundant, and sometimes may even dominate the
forest floor. The most common of these are
probably Diospyros elliptica and Garuga j70ri-
bunda, but composition depends upon which trees
dominate in the area. Littoral shrubs such as
Colubrina asiatica (fisoa) and Clerodendrum