american samoa - University of Hawaii at Manoa

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even mature secondary forest, it leaves an opening in thc canopy it may even take a few other canopy individuals with it when it falls. The canopy opening allows secondary forest trees to become established in primary forest. However, many primary forests lack any of the major secondary forest species, which possibly indicates the gaps routinely occurring in forests do not allow enough light to favor secondary forest species. The most characteristic secondary forest species in Samoa is Rhus taitensis (tavai), which grows to be a huge tree. Large areas of forest dominated by this tree occur on Tutuila. It can be recognized from a distance by its layered branches tinted red with young leaves, and in aerial photographs by the even texture of the canopy. It may dominate alone, or it may share dominance with another species, Alphitonia zizyphoides (toi). Other typical secondary species include Canunga odorata (ilangilang, moso'oi), Bischqfia juvanica ('o'a), Elattostachys falcata (taputo'i), Neo-nauclea forsteri (afa), and Macarangm stipulosa (lau fatu). However, these rarely become dominant, and the latter species is probably typical of gap replacement. Several other trees are somewhat intermediate between primary and secondary forest species. Dyso- xylum maola (maota) and Dysoxylum samoense (mamala) are species that appear in young secondary forest. In alluvial valleys they may completely dominate, but elsewhere they may disappear or comprise only a minor part of the relative dominance. Pometia pinnalri (tava) is a dominant primary forest species on area of rocky soil from recent lava flows (i.e., as it was on thc 'fafuna plain before the native vegetation was dccimatcd), but on hillsides it appears to be a pioneer species. This is a moot point, however, because I'ometia has not been recorded from the north side of the island and consequently not within the park boundaries. Another species should also be mentioned, Paraserianthes falcataria. This introduced tree is common along the beginning part of the Alava Ridge road, but since it has small, poorly dispersed seeds, it does not readily spread. The most significant secondary forest in the park is found on the slopes below Alava Ridge road and above Fagasa Bay. The dominant species here is probably Neonauclea forsteri (afa), but nearly as common are several other species, including Dyso- xylum samoense, Rhus taitensis, Alphitonia zizyphoides, Myristica fatua (Samoan nutmeg, 'atone), Bischofia javanica ('o'a), and Cananga odorata. It is not apparent why these ridges are covered with secondary forest. There is no sign of current agriculture, although there is on the ridges farther east along the road (see Fig. 20), and the presence of large trees suggests that agriculture is not the cause. Although the area seems far enough above Fagasa to be unlikely as a plantation area, it may have been utilized for this long ago-long enough ago that no signs of any plantation exist now. Perhaps the most likely explanation is that the steep slopes are unstable, resulting in a "disclimax" vegetation of secondary forest. This is somewhat similar to the "Dysoxylum lowland forest on talus slopes and cliffs" described from Ta'u (Whistler 1992b). The disturbed condition may have been abetted by erosion from the ridge road. Another area of secondary forest is found on the slope below the road just to the west of Amalau Valley. The dominant species here is probably Dysoxylum maota (maota), but also common are Cananga odorata, Kleinhovia hospita, Garuga jloribunda (vivao), Planchonella samoensis (ma- malava), and Ficus scabra (mati). This forest is a combination of ridge lowland forest, valley lowland forest, and secondary forest species, and is possibly on land that was formerly cultivated. DISCUSSION AND RECOMMENDATIONS Two or three decades ago, Samoa had the highest percentage of intact native vegetation of any Polynesian archipelago. This may still be true, but since then nearly all of the forests of the lowlands (up to about ca. 400 m elevation) have been felled for their timber or cut and burned for agriculture to keep up with the population growth of the islands. The park is important because of the native vegetation it contains. Some of the best lowland forest remaining in the archipelago is found on Tutuila. It occurs in two main areas, one within the park boundaries between Fagasa and Afono, the other on the northwest Tutuila coast between the villages of Fagamalo and Fagasa. These two areas are similar in being mostly uninhabited (both
have one village in the middle) and consist of rugged coastlines and ridges covered with native forest. Thus the park represents a significant portion of the remaining lowland forest in American Samoa. It also represents a significant portion of the quality lowland forest of the whole archipelago as well, since much of the remaining lowland forest of Western Samoa was devastated by the recent hurricanes, while most of that within the Tutuila park is in relatively good condition. In addition to the lowland forest within the park, there is one area of another unique plant community, montane scrub, a vegetation type that is restricted in the archipelago to Tutuila. The park is also important for floristic reasons. The native flora of the whole archipelago consists of about 540 species of flowering plants and 230 species of ferns and fern allies. Tutuila is home to 57% of the native flowering plants of the archipelago and 50% of the native fern and fern allies. The park itself contains 39% (209 species) and 35% (81 species), respectively. There are 49 species of native orchids on the island, a number similar to that found in the rest of Polynesia (outside of Samoa) combined, and 30 of these have been recorded in the park. Consequently, this relatively small park on a small island comprising less than 5% of the total land area of the archipelago, is home to a significant percent of the total native flora of Samoa. The need to protect this area, and other sensitive areas is heightened because of the recent rapid population growth. While the population of Western Samoa is rising only slowly because of out-migration, and the population in Manu'a is decreasing, the population of Tutuila is rapidly increasing. Over the last 10 years, the population has increased 44% (Craig 1992) to about 46,600 (as of 1990) and at this rate will top 100,000 by the year 2010. Much of this population has settled in the Tafuna area, where the unique Pometia lowland forest that once covered the whole area has now been almost entirely wiped out. There will be increasing pressure for land, and for the development of roads into hitherto inaccessible areas. Thus the need to protect the few remaining areas of native vegetation cannot be over-emphasized. By merely designating an area as a National Park is not enough to protect the plants and animals in the area. The concept of a park is unheard of in the traditional "fa'asamoa," and the conflict that arises is complicated by the Samoan land tenure system and ancient concepts of land use. Unlike the situation with bats and some bird species, there are no individual plant species that are threatened by human activity at this time. But the plants are threatened by the loss of their pollinators and dispersers-typically the birds and bats. Their habitat is threatened. Thus the following recommendations are made. 1. Strict enforcement of hunting laws. There are laws on the books for American Samoa that prohibit shooting birds and bats, but such laws do not conform to Samoan tradition and for the most part are ignored. This lack of local support leads to weak enforcement. Even though there is a law against hunting birds and bats, there is no prohibition against importing shotgun shells, which are hardly used for anything but birds and bats. As far as enforcement in the park is concerned, stiffer penalties, including federal prison terms (if possible) may be effective, since nothing else has been found to work. Honest and diligent enforcement officers are needed-that have the integrity and courage to enforce laws and apprehend violators, even if the offenders are members of their own extended families. Perhaps some kind of village enforcement could be feasible, if the villagers can be made to understand how the loss of wildlife will eventually effect them. 2. Control of feral pigs within the park. There is currently a problem of feral pigs in parts of the park. Well-traveled pig trails were seen on some of the ridges. In the past the feral population was kept in check by local hunters, but with increasing urbanization and rising material culture, pig hunting has decreased to practically nothing. Perhaps a bounty on feral pigs, or hired hunters who, are allowed to keep the slain pigs, would be effective. The feasibility of traps and exclosures should also be studied. 3. Limiting vehicular access to the park. Most of the disturbance within the park is along the Alava Ridge road. As the pressure on land increases in the future, individuals may claim and clear even more land along the road, destroying the native vegetation. While traditional farming is allowed by the park agreement, there is no need to make it easier by improving access. The road should be blocked so that few if any vehicles can use the road (this would have to be worked out with families currently farming the area or living
Page 1 and 2: COOPERATIVE NATIONAL PARK RESOURCES
Page 3 and 4: TABLE OF CONTENTS I . INTRODUCTION
Page 5 and 6: LEGEND B \ PROPOSED PARK AREA OFU I
Page 7 and 8: Figure 3 VEGETATION TYPE MAP Tutuil
Page 9 and 10: Figure 4. Pago Pago Bay, with Mt. M
Page 11 and 12: 'IJpolu, and 'Ta'u as well). The on
Page 13 and 14: nu pucijicuJ; an Eurya? [Eurya pick
Page 15 and 16: category recognized in the report o
Page 17 and 18: Figure 10. Tuafanua Beach west of V
Page 19 and 20: Figure 12. Littoral shrubland veget
Page 21 and 22: Figure 14. Littoral shrubland veget
Page 23 and 24: Figure 16. Littoral forest north of
Page 25 and 26: Soils differ in origin and age of t
Page 27 and 28: example on Tutuila is the climbing
Page 29 and 30: When undisturbed, the floor of the
Page 31 and 32: incrme (aloalo tai) may also be com
Page 34 and 35: coastal ridges, decreases in import
Page 36 and 37: Scvcral other trees are characteris
Page 38 and 39: poIvon/l~os, Dtrvulliu solidu (whic
Page 40 and 41: Although Mauga-o-Tula lacks some of
Page 42 and 43: introduced weeds, many of the Polyn
Page 46 and 47: there). No increased access should
Page 48 and 49: Whistler, W. A. 1976. Wetlands of A
Page 50 and 51: Acrostichum aureum L. [swamp fern]
Page 52 and 53: Uncommon in montane to cloud forest
Page 54 and 55: 171 ; Setchell 393; Christophersen
Page 56 and 57: of the costa. Uncommon in montane t
Page 58 and 59: liom China to I'itcairn Island. USE
Page 60 and 61: lamina deeply cut into 1-10 lobes,
Page 62 and 63: Antrophyum alatum Bracken. VITTARIA
Page 64 and 65: weed in villages and along roadside
Page 66 and 67: 650 111 clevi~tion. A modern introd
Page 68 and 69: Vernonia cinerea (L.) Less. [ironwe
Page 70 and 71: Uncomnion in secondary forest, prob
Page 72 and 73: from near sea level to 400 m elevat
Page 74 and 75: *Charnaesyce prostrata (Ait.) Small
Page 76 and 77: elevation. A modern introduction, n
Page 78 and 79: Macroptilium lathyroides (L.) Urb.
Page 80 and 81: Cyrtandra samoensis A. Gray momolea
Page 82 and 83: 'Thespesia populnea (L.) Sol. ex Co
Page 84 and 85: Ficus prolixa Forst. f. [banyan] ao
Page 86 and 87: found in Tonga, Futuna, and Fiji. S
Page 88 and 89: Peperomia pellucida (L,.) Kunth POL
Page 90 and 91: *Gardenia taitensis DC. "Hedyotis c
Page 92 and 93: elevation. This species should be t
Page 94 and 95:
"Physalis angulata L. 1 wild cape g
Page 96 and 97:
*Etatosterna scabriusculum Setchell
Page 98 and 99:
Epipremnum pinnaturn (L.) Engl. Ili
Page 100 and 101:
Mariscus secmannianus (Boeck.) Pall
Page 102 and 103:
*Bulbophyllurn samoanum Schlechter
Page 104 and 105:
Malaxis resupinata (Forst. f.) Kunt
Page 106 and 107:
F. homhronii Mart.; it differs from
Page 108 and 109:
this in D. ciliaris, but the two ha
Page 110 and 111:
Paspalurn orbiculare Forst. f. Mcdi
Page 112 and 113:
APPENDIX B: PLOT DATA (Basal area i
Page 114 and 115:
PLOT 4: MULIULU LOWLAND RIDGE FORES
Page 116 and 117:
PLOT 6: TIATAUALA LOWLAND RIDGE FOR
Page 118 and 119:
PLOT 8: OLO LOWLAND RIDGE FOREST (2
Page 120 and 121:
PLOT 10: AMALAU LOWLAND VALLEY FORE
Page 122 and 123:
PLOT 12: ALAVA MONTANE FOREST* (400
Page 124 and 125:
APPENDIX C: SEASONALITY OF IMPORTAN
Page 126 and 127:
MORACEAE Ikus godcfl'royi 1;icus ob
Page 128 and 129:
SPECIES FAMILY FLOWERING DATES FRUI
Page 130 and 131:
2. Littoral Shrubland Two types of
Page 132 and 133:
the relatively undisturbed places,
Page 134 and 135:
harvcyana (laupata), Morinda citrif
Page 136 and 137:
APPENDIX F. SUMMARY OF THE VASCULAR
Page 138 and 139:
VIlTAKIACEAE Amrophyurn alaturn Ant
Page 140 and 141:
Species FAMILY Status* E I P M ....
Page 142 and 143:
MYRSINACEAE Embelia vaupelii Maesa
Page 144 and 145:
Species FAMILY Status* E I P M VEKB
Page 146:
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