american samoa - University of Hawaii at Manoa

2. Littoral Shrubland
Two types of littoral shrubland are present in the
park, one on the sandy beaches where it alternates
with littoral forest and herbaceous strand, and the
other on the rocks of Sunitao and steep maritime
cliff running inland along most of the length of the
park. The most common shrub mixed in with the
other littoral plants on the sandy beach is the beach
sunflower Wollastonia bijlora (beach sunflower,
skate), with lesser amounts of Scaevola taccada
(to'ito'i), Sophora tomentosa, Colubrina asiatica
(fisoa), and Clerodendrum inerme (aloalo tai).
Sophora should be considered a rare plant in Samoa;
it is known in the archipelago from only one beach
on 'Upolu, one on Tutuila (Nu'uuli Point), the south
part of 'Aunu'u, and this Ofu beach.
The littoral shrubland on the steep sides of
Sunitao and the cliffs of the main part of Ofu are
much more complex and inaccessible. The slopes of
Sunitao are dominated by a mixture of littoral trees
and shrubs. Because the trees are often dwarfed, it
is perhaps best to consider this vegetation as littoral
shrubland, as was done with the vegetation of Pola
Islet and the cliffs of Pola'uta Ridge on Tutuila.
Littoral forests, however, are present on the gentler
slopes of Sunitao and are discussed below.
The dominant plants in the littoral shrubland of
Sun itao are Dendrolobium umbellatum (lala),
Clerodendrum inerme, Hibiscus tiliaceus (beach
hibiscus, fau), and Pisonia grandis (pu'avai). To
label the vegetation between the littoral forest and
lowland forest on the cliffs on the main part of Ofu
as littoral shrubland seems a bit incongruous since
this community is supposed to be between the shore
and the littoral forest. However, since it is compo-
sed of shrubby species rather than trees, it is best to
consider it littoral shrubland, regardless of its
location.
The dominant species on the steep slopes are
Dendrolohium umbellatum, Phymatosorus scolo-
pendria, Davallia solida (laugasese), Clerodendrum
inerme, and Wollastonia bipora. Other species
noted here include Morinda citrifolia (Indian mul-
berry, nonu), Syzygium dealatum (asi vai), Ipomoea
macrantha, Pipturus argenteus (soga), Pisonia
grandis, Macaranga harveyana (lau pata), Colu-
hrina asiafica, and GarugafIoribunda (vivao).
Two other less common species were also noted
here. The first, Gossypium hirsutum (vavae), is the
native species of cotton that is very rare on Tutuila
(one location recorded) and 'Aunu'u, and this was a
surprising record for Ofu. The other, Plumbago
zeylanica, was reported twice from the adjacent
Olosega, but this is a new record for Ofu. Both
species should be considered rare in American
Samoa.
3. Littoral Forest
The division between this community and littoral
shrubland is not very distinct on Ofu, especially
when the slopes get steeper and trees get more
shrubby. However, three types of littoral forest
were recorded. The first is found on the rocky
shores of Sunitao. Some of these slopes have been
disturbed--the forest has been cut down and the area
replanted with coconuts and bananas. This is parti-
cularly the case on the east side of the mountain.
Probably the natural littoral forest there was domi-
nated by Barringtonia asiatica, as it is on the
southwest side, and is similar to what is found in the
Tutuila park unit.
The gentle slopes leading up to the steeper slopes
and cliffs are dominated by the second kind of lit-
toral forest. A sample on the southwest side, inland
of the Barringtonia littoral forest, showed it to be
dominated by a mixture of littoral forest trees. In
descending order of dominance, these are Hernan-
dia nymphaeifolia (Chinese lantern-tree, pu'a),
Erythrina variegata (coral tree, gatae), and Pisonia
grandis (pu'avai). Of lesser importance are Diospy-
ros samoensis ('au'auli), which was the most com-
mon tree present, Hibiscus tiliaceus (beach hibiscus,
fau), Dysoxylum samoense (mamala), Ficus scabra
(ma ti), Guettarda speciosa (pua pua), Syzygium
dealatum (asi vai), and Sterculia fanaiko (fana'io).
Strangely, there was no Barringtonia in the sample
on this slope. The understory was strongly domi-
nated by seedlings and saplings of Syzygium
dealatum and Diospyros samoensis, with lesser
amounts of Psychotria insularum (matalafi), and
Morinda citrifolia. Other significant plants included
the bird's-nest fern Asplenium nidus (laugapapa)
and Cordyline fruticosa (ti), with a few other
species. The ground cover was relatively light, with
perhaps only 15% cover. The only vines noted were
Epipremnum pinnatum, Dioscorea bulbifera (bitter
yam, soi), and Faradaya amicorum (mamalupe). A