Fijian Vegetation That Approximates to Savanna Today Is on the So-Called Talasiga (Sunburnt) Land

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Plant Formations in the Fijian BioProvince

Peter Martin Rhind

Fijian Tropical Rain Forest Although these forests have an affinity with the dipterocarp forests of the Indo-Malayan region they lack both their stature and species-richness, but in this respect they are typical of Pacific island rain forests. They range in height from about 6-15 m but occasionally have emergents reaching up to 35 m. On Tutuila in the Samoan Islands they are dominated by the endemic Dysoxylum maota (Meliaceae) and Planchonella samoensis (Sapotaceae). Other significant trees include Bischofia javonica, Canango odorata, Ficus scabra, Kleinhovia hospita, Inocarpus fagifer, Myristica fatua and the endemic Canarium vitiense (Burseraceae), Elaeocarpus ulianus (Elaeocarpaceae) and Macaranga stipulosa (Euphorbiaceae). The forest floor is generally open and dominated by shade-tolerant ferns such as Arthropteris repen and the endemic Lomagramma cordipinna (Lomariopsidaceae). Epiphytes are abundant with Aplenium nidus being the most common species, but there are many other ferns and orchids such as Dendrobium dactylodes. Likewise lianas are also common. Hoya pottsii and the endemic Alyxia bracteolosa (Apocynaceae) and Gynochtodos epiphytica (Rubiaceae) are the most typical species.

In coastal forest, such as on Matapai Point, the endemic Diospyros samoensis (Meliaceae) becomes the main species, while other endemic taxa found here include Diospyros elliptica (Meliaceae), Planchonella garberi (Sapotaceae), Sterculia fanaiho (sterculiaceae), Syzygium dealatum (Myrtaceae) and the fern Tectaria stearnsii (Aspidiaceae). The principal trees in Fiji include Agathis macrophylla, Burckella parvifolia, Calophyllum neo- ebudicum, Endiandra gillespiei, Myristica micrantha, Planchonella lingensis, Syzygium effusum and the endemic Canarium vitiense (Burseraceae), Degeneria vitiensis (Degeneriaceae), Dysoxylum richei (Meliaceae), Endospermum macrophyllum (Euphorbiaceae), Flacourtia vitiensis (Flacourtiaceae), Garcinia myrtifolia (Clusiaceae), Neuburgia alata (Loganiaceae) and Pandanus joskei (Pandanaceae). Shrub and ground layer species typically include Crossostylis richii, Pittosporum rhytidocarpon, Selaginella breyniodes, Streblus pendulinus, and endemics such as the palm Balaka macrocarpa (Arecaceae), the mega herb Alpinia baia (Zingiberaceae) and the saprophytic herb Andruris vitiensis (Triuridaceae). Other endemic species recorded for these forests include Acanthephippium vitiense (Orchidaceae), Airosperma trichotomum, Ixora maxima, Readea membranacea, Squamellaria imberbis, Xanthophytum calycinum (Asteraceae), Aristolochia vitensis (Aristolochiaceae), Astronidium floribundum (Melastomataceae), Burckella fijiensis (Sapotaceae), Connarus pickeringii (Connaraceae), Firmiana diversifolia (Sterculiaceae), Flagellaria gigantea (Flagellariaceae), Freycinetia caudata (Pandanaceae), Geniostoma macrophyllum (Loganiaceae), Gonostylus punctatum (Gonystylaceae), Ilex vitiensis (Aquifoliaceae), Orthiopteris tenuis (Pteridaceae), Podocarpus descipiens (Podocarpaceae), Saurauia rubicunda (Saurauiaceae) and Syzygium amplifoliaceae (Myrtaceae).

Fijian Cloud Forest These highly humid forests are scattered on the ridges and peaks of various islands above an altitude of about 400 m including Futuna and the larger islands of Fiji and Samoa. They are frequently enveloped in cloud and typically occur where humid offshore winds rise over coastal ranges. The characteristic trees on the Samoan island of Tutuila are Crossostylis biflora, Fagraea berteroana, Hernandia moerenhoutiana, Syzygium samarangense, Trichospermum richii and the endemic Dysoxylum samoensis (Meliaceae), Elaeocarpus tonganus (Elaeocarpaceae), Hedycarya denticulata (Monimiaceae) and Palaquium Copyright © 2010 Peter Martin Rhind stehlinii (Sapotaceae), while on Savai’i species such as Omalanthus acuminatus, Streblus anthropophagorum and the endemic Coprosma savaiiense (Rubiaceae), Dysoxylum huntii (Meliaceae), Reynoldsia pleiosperma (Araliaceae) and Weinmannia samoense (Cumoniaceae) predominate. Ground cover is typically dense and dominated by shade- tolerant ferns, herbs and flowering shrubs. Among the many ferns encountered is the small, endemic tree fern Cyathea vaupelii (Cyatheaceae). There are also a number of endemic shrubs belonging to the genera Cyrtandra and Psychotria and the endemic blueberry Vaccinium whitmeei (Ericaceae). Epiphytes occur in profusion. Most of the vascular plants are either ferns or orchids, and in fact the only vascular epiphyte that did not belong to one of these groups on Tutuila was Procris pedunculata – a member of the nettle family (Urticaceae). On Mount Koroturanga (1210 m) on the Fijian island of Taveuni these forests can be very stunted sometimes growing no higher than about 3 m. The endemic trees Ascarina swamyana (Chloranthaceae) and Spireanthemum serratum (Cunoniaceae) are more or less confined to these forests together with several epiphytes such as the endemic Medinilla waterhousei (Melastomataceae). Other endemics recorded here include Alstonia vitiensis (Apocynaceae), Calophyllum vitiense (Hypericaceae), Citronella vitiensis (Cardiopteridaceae), Clinostigma exorrhizum (Arecaceae), Cyrtandra tempestii (Gesneraceae), Decaspermum vitiense (Myrtaceae), Fagraea vitiensis (Loganiaceae), Ficus barclayana (Moraceae), Freycinetia urvilleana (Pandanaceae), Macropiper vitiense (Piperaceae), Randia vitiensis (Rubiaceae), Rapanea myricifolia (Myrsinaceae), Sterculia vitiensis (Sterculiaceae) and Trichospermum richei (Tiliaceae).

Fijian Summit Scrub Scrub covers the summits of various islands including Ta’u and Tutuila in Samoa and Tafahi in northern Tonga. In Ta’u its presence seems to relate to the fact that forest was destroyed by relatively recent hurricanes. The dominant taxa include the endemic shrub Freycinetia storckii (Flagellariaceae), tree ferns (Cyathea) and terrestrial ferns such as Blechnum vulcanicum and Dicksonia brackenridgei. A similar type of vegetation occurs on Tafahi, but this appears to be more of a climax community. The dominant shrubs here are Geniostoma rupestre, Maoutia australis and the endemic Cyrtandra samoensis (Gesneraceae). On Tutuila the situation is slightly different in that all the shrubby vegetation is confined to the summits of ‘trachyte plugs’ (old volcanic cores). Here trees such as the endemic Astronidium pickeringii (Melastomataceae), Erythrospermum acuminatissimum (Flacourtiaceae), Pandanus reineckei (Pandanaceae), Psychotria insularum (Rubiaceae) and Syzygium brevifolia (Myrtaceae) are found in a tangle of ferns, shrubs and climbers. Ground flora in most of these scrub communities seems to be largely dominated by ferns such as Dicranopteris linearis and Dipteris conjugata.

Fijian Volcanic Scrub Relatively recent lava flows are found on various islands including Niuafo’ou, Sauai’i and several small islands in Tonga. On Savai’i a series of eruptions in which volcanic material reached the coast occurred in 1760 and between 1905-1911. The vegetation that colonized these areas is still largely confined to cracks and crevices. Dominant trees include Fagraea berteroana, Glochidion ramiflorum and the endemic Ayrtera brackenridgei (family?). In more upland areas at elevations of about 1500 m species composition changes to one largely dominated by the endemic Coprosma strigulosa (Rubiaceae), Spiraeanthemum samoense (Cononiaceae) and Vaccinium whitmeei (Ericaceae). At ground level two native ferns, Davallia solida and Nephrolepis hirsutula are common, while on Niuafo’ou the ancient pteridophyte Psilotum nudum can be found in similar situations. However, these volcanic areas are far from uniform and in places there are ash plains virtually devoid of shrubs and mainly dominated by the grass Imperata conferta.

Copyright © 2010 Peter Martin Rhind Fijian Tropical Savanna Although most of these open forests have been destroyed their original composition can be determined from remnants on leached soil and on the drier, leeward side of the larger islands. They are xerophytic in character and variously composed of low trees such as Acacia richii, Alphitonia zyzyphoides, Dodonaea vicosa and the endemic Fagraea gracilipes (Loganiaceae), together with the parasitic sandalwood (Santalum yasi), Casuarina equisetifolia and various Pandanus species. The ground layer is dominated by Dicranopteris linearis, Lycopodium cernuum and Pteridium esculentum. However, most of the Fijian vegetation that approximates to savanna today is on the so-called talasiga (sunburnt) land. The term applies to fire-modified ecosystems, and in addition to some of the above-mentioned species, there are various non-indigenous species such as Sporobolus indicus. This type of vegetation now covers nearly a third of Viti Levu and Vanua Levu, and relates to the fact that the original Fijians frequently used fire as part of their shifting cultivation technique. Other talasiga species include the native reed Miscanthus floridulus and the introduced African pyrophyte Pennisetum polystachyon (mission grass).

Further information required.

References

Ash, J. 1987. Stunted Cloud-forest in Taveuni, Fiji. Pacific Science, 41: 191-199.

Ash, J. 1992. Vegetation Ecology of Fiji: Past, Present, and Future Perspectives. Pacific Sciences, 2: 111-127.

Balgooy, Van. M. M. J. 1960. Preliminary plant geographical analysis of the Pacific. Blumea, 10: 385-430.

Balgooy, Van. M. M. J. 1969. A study of the diversity of island floras. Blumea, 17: 139-178.

Campbell, D. G. & Hammond, H. D. 1989. Floristic Inventory of Tropical Countries. The New York Botanical Garden.

Drake, D. R., Whistler, W. A., Motley, T. J. & Imada, C. T. 1996. Rain forest vegetation of ‘Eua Island, Kingdom of Tonga. New Zealand Journal of Botany, 34: 65-77.

Gardger, R. O. 1997. New and noteworthy plants from Fiji. New Zealand Journal of Botany, 35: 487-492.

Garnock-Jones, P. J. 1978. Plant communities on Lakeba and southern Vanua Balavu, Lau group, Fiji. Royal Society of New Zealand Bulletin, 17: 95-117.

Ghazanfar, S. A., Keppel, G. & Khan, S. A. 2001. Coastal vegetation of small islands near Viti Levu and Ovalau, Fiji. New Zealand Journal of Botany, 39: 587-600.

Gillison, A. M. Tropical Savannas of Australia and Southwest Pacific. In: Ecosystems of the World 13 - Tropical Savannas. Ed. F. Bourliere. Elsevier Scientific Publishing Company.

Keppel, G. 2002. Coastal vegetation of Taunovo Bay, Pacific Harbour, Viti Levu, Fiji – A proposed development site. South Pacific Journal of Natural Science, 20: 25-29.

Kirkpatrick, J. B. & Hassall, D. C. 1981. Vegetation of Sigatoka sand dunes, Fiji. New Zealand Journal of Botany, 19: 285-297.

Kirkpatrick, J. B. & Hassall, D. C. 1985. The vegetation and flora along an altitudinal transect through tropical forest at Mount Korobaba, Fiji. New Zealand Journal of Botany, 23: 33-46.

Krupnick, G. A. & Kress, W. J. 2003. Hotspots and ecoregions: a test of the conservation priorities using taxonomic data. Biodiversity and Conservation, 12: 2237-2253.

Leith, H. & Werger, M. J. A. 1989. Ecosystems of the World 14B - Tropical Rain Forests. Elsevier Scientific Publishing Company.

Merlin, M. D. & Juvik, J. O. 1995. Montane cloud forest in the tropical Pacific: some aspects of their floristics, biogeography, ecology, and conservation. In: Tropical Montane Cloud Forests. Eds. L. S. Hamilton, J. O. Juvik and F. N. Scatena. Ecological Studies 10. Springer-Varlag.

Mueller-Dombois, D. & Fosberg, F. R. 1998. Vegetation of the Tropical Pacific Islands. Springer.

Setoguchi, H., Ohba, H. & Tobe, H. 1998. Evolution in Crossostylis (Rhizophoraceae) on the South Pacific Islands. In: Evolution and Speciation of Island Plants. Eds. T. S. Stuessy and M. Ono. Cambridge University Press.

Schmid, M. 1978. The Melanesian forest ecosystems (New Caledonia, New Hebrides, Fiji Islands and Solomon Islands. In: Tropical forest ecosystems. Natural Resources Research Vol. XIV. UNESCO

Schmid, M. 1989. The forests in the tropical Pacific archipelagoes. In: Ecosystems of the World 14B - Tropical Rain Forest Ecosystems. Elsevier.

Sohmer, S. H. 1990. Elements of Pacific phytodiversity. In: The Plant Diversity of Malesia. Proceedings of the Flora Malesiana Symposium commemorating Professor Dr. C. G. G. J. van Steenis Leiden, August 1989. Eds. P. Baas, K. Kalkman and R. Geesink. Kluwer Academic Publishers.

Thorne, R. F. 1965. Floristic relationships of New Caledonia. University of Iowa Studies in Natural History, 20: 1-14.

Schmid, M. 1989. The forests in the tropical Pacific archipelagoes. In: Ecosystems of the World 14B - Tropical Rain Forest Ecosystems. Elsevier.

Smith, A. C. 1951. The Vegetation and Flora of Fiji. Scientific Monthly, 73: 3-15.

Smith, A. C. 1954. Botanical studies in Fiji. Smithsonian Institute Report for 1954, 305-315.

Smith, A. C. 1955. Phanerogam genera with distributions terminating in Fiji. Journal of the Arnold Arboretum, 36: 273-292.

Smith, A. C. 1979. Flora Vitiensis Nova. A New Flora of Fiji. Vol. 1. Lawai, Kauai, Hawaii.

Uhe, G. 1974. The composition of the plant communities inhabiting the recent volcanic ejecta of Nuiafo’ou Tonga. Tropical Ecology, 15: 126-139.

Whistler, W. A. 1980. The vegetation of Eastern Samoa. Allertonia, 2: 45-174.

Whistler, W. A. 1983. Vegetation and flora of the Aleipata Islands, Western Tonga. Pacific Science, 37: 227-249.

Whistler, W. A. 1983. Vegetation of Samoa and Tonga. Pacific Science, 46: 159-178.

Whistler, W. A. 1995. The Cloud Forest of Samoa. In: Tropical Montane Cloud Forests. Eds. L. S. Hamilton, J. O. Juvik and F. N. Scatena. Ecological Studies 10. Springer- Varlag.