82

VEGETATION OF TUVALU

Colin D. Woodroffe

Department of Geography University of Wollongong, Wollongong, NSW 2500 Australia

ABSTRACT The nine islands of Tuvalu exhibit a complex mosaic of different vegetation units; a major part is covered with coconut woodland, but there are remnants of natural broadleaf woodland, and a series of coastal and inland scrub types. Fony-nine vegetation units were discriminated and mapped as a part of a Land Resources Survey of the islands. The most widespread of these are described, with particular emphasis on detailed mapping and field description from NuL Collection and sight records of pla,nts from the Tuvalu atolls and reef-top islands are listed. Although the islands have only a limited flora, largely of pantropical and easily dispersed species, principally as a result of the probable recolonisation of the islands by terrestrial biota during the Holocene, there are some notable anomalies in the distribution of several plants which indicate the complexity of the dispersal and establishment processes operating in such remote archipelagoes.

INTRODUCTION There are a number of different island types in the Pacific basin. Figure I (modified from Scott and ~otondo, 1983) illustrates some of the main types. The simplest island is a basaltic volcanic island (i.e. Hawaii). Such an island may be surrounded by a fringing reef as on recent lava flows on Hawaii, or by a barrier reef with a lagoon separating the reef from land (Le. Tahiti). An almost atoll, where only a small remnant of the volcanic mass remains above

S. Pa.c. 1. Nat. Sci., 11:82-128 al Volcanic island bl Volcanic island c) Volcanic island 83 with no fringing with fringing reef with emerzent reef and fringing reefs &J ~/":: ~:. :~~:~~:.:~

1) Reef-top island

gl Emergent hlEmergent atoU j) Makatea island limestone island

[BJ Volcanic rocks § Limestone 0 Holocene reef and island sediments

Figure 1 Main types of islands on the Pacific plate (modified from Scott and Rotondo, 1983). Initial Eroded Atoll Limestone Modem Form Island Atoll (Karst) S.L.-...... -.,..-- SL·li·· ···· -a!,=~e)Reef growth SL. '" -M~" .' Present (\,\ (\ ,- I o Sea Level I \ I \ '\ I I \ I .... I I : v J 50 J J I Depth J "J I " I \ I 100 (metres) " , , I \ J '..J '...1 150 160 120 80 40 0 Time (thousands of years before present)

Figure 2 Late Quaternary sea-level fluctuations and their effect on coral atolls. The lower diagram shows actual reconstruction of sea level and ocean volume variations for the last 140,000 years, based on raised coral reefs in New Guinea and oxygen isotope analysis of deep-sea cores (after Chappell and Shackleton, 1986). The atoll is gradually subsiding. 84 sea level and the reef is dominated by low, carbonate reef islands like those found on an atoll, represents a funher stage in the evolutionary sequence of coral atoll development envisaged by Darwin (i.e. Aitutaki, Cook Islands). Still funher subsidence results in the total disappearance of all of the volcanic mass beneath the sea, but the continued upward growth of the surrounding reef. Islands of carbonate sands and rubble form on the surrounding reef and the island is known as an atoll (i.e. Bikini and Eniwetak, Marshall Islands).Within groups of atolls there are sometimes smaller reef platforms which do not contain an interior lagoon, but which have an island over most of the area of the reef platform; these are termed reef-top islands in this account (i.e. Niutao, Tuvalu). The sequence of islands, young volcanic island, island with fringing reef, island with barrier reef, almost atoll, atoll, is found in several linear island chains that occur in the Pacific Ocean, on which potassium-argon dating of basalts has shown an increasing age towards the northwest. These chains are a spatial analogue of the temporal stages through which anyone island may go. Beyond the northwestern-most island in the chain there are often submerged seamounts and guyots that represent further stages in the subsidence sequence (Grigg and Epp, 1989).

Three other types of emergent island can be identified. An emergent atoll is an island that maintains an atoll form but upon which there are Pleistocene limestones above present sea level (i.e. Aldabra, western Indian Ocean). An emergent limestone island is an island which has lost any atoll form that it may have had. A makatea island is one on which there is a highly eroded and degraded volcanic interior, surrounded by emergent limestones (i.e. Makatea in French Polynesia). Emergent limestone islands, while common at plate margins, can also be found on oceanic plates situated up-plate of a subduction zone. It appears that the islands may be located on a flexed bulge of the plate prior to subduction (i.e. Niue).

In biogeographical accounts of Pacific islands it has been usual to divide islands into only two categories, high islands and low islands. The high islands comprise all of the above types except coral atolls and reef-top islands which are low. Accounts of the biota of the Pacific tend to concentrate on the high islands for it is on these that there are high incidences of endemism of flora and evidence for recent speciation of fauna. The atolls and reef- top islands by contrast tend to be depauperate in species and characterised by pantropical, drift-dispersed flora (Fosberg, 1984).

The reason for this disparity is almost certainly that the atolls and reef-top islands are composed entirely of sediments of Holocene age (formed in the last 10,000 years), and that during that period they have been submerged beneath the sea entirely as sea level has risen since the last ice age, such that they have had to be completely recolonised by plants in the last few thousand years. High islands on the other hand have retained their biota over this 85 period. The pattern of late Quaternary sea-level fluctuation, reconstructed from oxygen isotope analysis of deep sea cores and radiometric dating of reef terraces on an uplifting coast of New Guinea (Chappell and Shackleton, 1986) is shown in Figure 2. The last time at which the sea was around its present level was during the last interglacial, about 120,000 years ago. Reefal limestones of that age are a common feature of islands in the Pacific, and their relative elevation gives an indication of the vertical movement of individual islands since that time (Fig. 1). Atolls, as shown by drilling on Eniwetok, Bikini, Mururoa,Tarawa and the Cocos (Keeling) Islands, have subsided at rates of around 0.1 mrn/yr.

When sea level was high an atoll perhaps somewhat similar to that presently found, would have existed where there are atolls today. When sea level was low, that atoll was exposed up to 100 m above the sea as an emergent limestone island, and it underwent solution giving rise to a highly eroded karst surface (Figure 2). During the 100,000 years or so that it has taken for the sea to return to its present level, the atoll has gradually subsided so that the former (last interglacial) surface is about 10-20 m below present sea level beneath the present atoll. This surface has been identified on a number of rtolls (7-14 m on Eniwetok, Szabo et al., 1985; 8-17 m on Tarawa, Marshall and Jacobsen, 1985; 8-12 m on Cocos (Keeling) Islands, Indian Ocean, Woodroffe et al., in press). The upper 10 or 20 m of reefal limestones and unconsolidated sediments built up in the Holocene (the last 10,000 years), with coral establishment over the karstic last interglacial limestones recommencing about 8000 years ago (Marshall and Jacobsen, 1985). At that time the older limestone basement was flooded and reef growth lagged behind sea level. Only since sea level has stabilised during the last few thousand years has reef growth caught up with sea level, reef flats typical of Pacific islands developed, and reef islands formed on the reef flat. In many cases reef island formation has been made easier by a fall of sea level of about I m during the last 3000-4000 years (Pirazzoli and Montaggioni, 1986). On the majority of atolls the entire terrestrial biota would have been eradicated 8000 years ago (and perhaps episodically prior to that time) when the sea submerged the last interglacial limestone substrate of the atoll, and, as no evidence of reef islands existing during the subsequent phase of catch-up reef growth has been found, probably could not have recolonised until around 3000 years ago when the present reef islands began to form.

The flora and vegetation of atoll reef islands therefore represent the results of relatively recent transoceanic dispersal and colonisation. The reef islands ihemselves appear superficially rather simple and vary little from archipelago to archipelago. Comparison of flora and vegetation of different reef islands provides an opportunity to decipher the detail of ecological processes, such as dispersal and establishment of propagules. This approach received an enormous stimulus from the pioneering theories of island biogeography proposed by 86

MacArthur and Wilson (1967), who postulated a dynamic equilibrium between species diversity and the size and remoteness of islands.

The relatively recent development of reef islands on atolls, has also coincided with human colonisation of the Pacific. Clearly atolls could not be colonised before reef islands had developed, but the archaeological record from mid-Pacific high islands aePears to indicate that colonisation of those islands also occurred around 3000 years ago (Bellwood, 1978; Gibbons and Clunie, 1986). People have had a profound influence on the vegetation of atolls, most notably through the widespread preferential planting and maintaining of coconut woodlands. Coconut woodland would not be as widespread naturally as it is at present. Coincidentally, it seems that many reef islands may have been subject to human influence for the majority of the time that they have been in existence.

Tuvalu, formerly the Ellice Islands of the Gilbert and Ellice Islands, is a particularly remote group of islands in the Central Pacific. The nine islands comprise five atolls and four reef-top islands, each on its own reefal platform. The vegetation and flora of the islands has received only sporadic attention. Most of the botanical collections have been made on the main island, Funafuti. The earliest account of Tuvaluan plants is by von Milller (1876). Hedley (1896) described Tuvaluan plants and their uses. Mrs Edgeworth David (1899) collected plants during her residence on Funafuti as part of the Royal Society of London expedition to core the atoll, and her plants and those collected by Halligan and Finckh in i898 were described by Maiden .(1904). Koch (1961) described and collected plants from Niutao (deposited at the Smithsonian Institution), and Chambers (1984) collected and described plants and their uses from Nanumea (deposited at the BP Bishop Museum).

This account of the vegetation of Tuvalu is based upon studies undertaken for a Land Resources Survey of Tuvalu, funded by FAO/UNDP. contracted to the Department of Geography, University of Auckland, co-ordinated by Professor Roger McLean (McLean et ai., 1985, 1986a, 1986b, 1986c, 1986d, 1986e; McLean and Hosking, 1986). Mapping of vegetation of each of the islands, excepting the eatoll of Funafuti, was undertaken from stereoscopic black and white vertical aerial photographs. The photography was taken in 1971 most at scales of approximately 1: 10,000, though mapping of vegetation on Vaitupu was done from photographs at a scale of approximately I :30,000. Vegetation units were delineated, and in some cases canopies of individual trees could also be identified. Ground verification was undenaken to varying degrees. A preliminary survey of the vegetation of Vaitupu was undenaken in August 1981 (with additional ground-truthing in February 1982) from which an unpubiished repon has been prepared (Woodroffe, 1981). A detailed survey of the vegetation and flora of Nui was undenaken during two weeks in February 1982 (Woodroffe, 87 1985), and a fairly extensive collection on Nukulaelae, though not all reef islands were visited, was also undertaken in February 1982. Ground-truthing of vegetation on other islands in the group has been carried out either by the author, or more often by Professor Roger McLean, Mr Paul Holthus or Dr Peter Hosking as a part of the Land Resources Survey. Specimens from Yaitupu and Nui are deposited at DSIR Botany Division, Christchurch, New Zealand. Identifications were verified by Bill Sykes, Ray Fosberg or Marie-Helene Sachet. Further collections of plants from Yaitupu by Maddison and from Funafuti by Fitchett have been sighted for this account, but are not deposited in any herbarium.

This account is primarily a description of vegetation. Only on Nui has collecting been sufficiently intensive to have potentially enumerated the entire flora of an atoll or reef-top island (86 species; see Woodroffe, 1985). Appendix 1 lists collections and sight records of species, where these are known, on each of the atolls and reef-top islands; the accuracy and completeness of records is likely to differ between islands.

TUVALU FLORA Appendix 1 is not an exhaustive list of the flora of Tuvalu, but a record of the occurrence, reported in collections or sight records, of the more widespread species, on the nine islands. There are two major limitiations to this appendix. Firstly the nature and intensity of collection has differed for different islands, and secondly many different synonyms have been used in the accounts of vegetation of the group. Synonymy has been assumed, and the names adopted in this account are those preferred at the Smithsonian Institution.

A positive record in Appendix 1 is a reasonably reliable indication that the plant occurs, or did occur at the time of past inspection, on that island. However, lack of a record does not mean that the plant does not occur there, merely that no record is known. Records are most likely to be complete for trees, and least likely to be complete for herbs, grasses etc.

In some cases absences are based on detailed surveys and imply that the plant is not present on a particular island. Thus, mapping on Nui failed to find Hibiscus or Thespesia, and it seems certain that they were not there. Similarly fairly widespread investigations on Nukulaelae suggest that Rhizophora does not grow'1here. The records for shrubs are less complete; few studies, for instance, distinguish Pemphis and the superficially similar shrub Suriana, and the true extent of Suriana is probably greater than in Appendix 1, though nowhere does it form a distinct coastal scrub unit as it does in the Tuamotu Islands, Line Islands and Cook Islands (Doty, 1954: Stoddart and Sachet, 1969; Clapp and Sibley, 1971; Stoddart, 1975). 88

The thorny tree Ximenia has an interesting distribution, having been collected only from Nanumea and Nui. The shrub Procris is also interesting, being found only on one reef island, Fenualango, on Nukulaelae where it is widespread.

Even plants which are abundant on many of the islands of Tuvalu may be rare or absent on others. For instance, Acalypha is one of the commonest elements of inland scrub and the scrub layer beneath coconut woodland, especially on Nui and Vaitupu; however on Nukulaelae it was found only at one location, adjacent to the pulaka pits, where it had evidently been recently introduced. Neisosperma, though never a prominent element of the vegetation on any reef island, is surprisingly rare on Vaitupu where only one or two individuals were observed.

Appendix 2 lists selected local names for the most abundant plants. Tuvaluan names often differ slightly from atoll to atoll. Names on Nui can be substantially different from those in the rest of Tuvalu, often showing an affinitiy to the Kiribati name.

VEGETATION UNITS . A number of vegetation units are found throughout the . archipelago, and other distinct assemblages of plants occur on isolated islands. Below the major types of vegetation are described, with particular reference to their structure and floristic composition on Nui and Vaitupu. Detailed vegetation maps of the reef islands of Nui (after Woodroffe, 1985) are presented in Figures 3-7. Three broad categories of vegetation are recognised: coconut woodland; scrub, both coastal and inland; and broadleaf woodland. In addition to these and various combinations that occur, there are a series of ornamentals, garden plants and weeds ass6ciated with villages and pulaka pits (pits excavated for the cultivation of the taro Colocasia esculenta and Cyrtosperma chamissonis). Appendix 3 records the occurrence of 49 vegetation units, each with a convenient abbreviation, which were discriminated during the aerial photographic mapping of. Tuvalu as a part of the Land Resources Survey. Only the more extensive of these are described below. COCONUT WOODLAND Over much of the area of Tuvalu Cocos nucifera. the coconut is the dominant plant. Not all areas of coconut woodland are natural, but it is now impossible to deterinine the original vegetation of these areas. In addition to planting of coconuts, coconut plantations have been maintained to various degrees with different levels 'of scrub clearance and with replanting and underplantin-g of some areas of palms (Figure 8). Coconut woodland plays an important role in a number of levels of economy; some areas may be important for regular collection of 89

500 metres

~EGETAT I O N UNI'fS

ScBevola scrub

Spa~ Scaev?la scrub

Scaevola I Acalypha scrub

Scaevola I Acalypha scrub with Pisonia

Scaevola I Acalypha scrub with J.'parse coconut Tournefortla sc rub

Coconut woodland

Pisonia woodland

Pisonia I Hernandla woodland

Coconut woodland with Pisonla

Pulaka Pit

INDIVIDUAL TREES

Pisonia

Hernandla

Calophyllum

Barringtonia

Cordia

Toumefortia

Figure 3 Vegetation of Meang and Nusafe, Nui (after Woodmffe, 1985).

91

OrBits;

500 metres

VEGETATION UNITS

., Pemphls scrub

~ Sparse Pemphls scrub

Motulikiliki D SCae ..... ola scrub .... D Scaevola I Acalypha scrub Matuli/o 2 , ... <{.... 1 ~ ~ Scaevola I Acalypha scrub with sparse coconut

~ Tournefortla scrub Motu"ki~~. ri> Slk~/Bna ~ PipturUII I Acalypha I Scaevola scrub § Coconut woodland

~ Pison!a woodland Pakantou § Coconut woodland wIth Piscnia INDIVIOUAL TREES

Plson'a

Hernandia

CaJophylium

Barrlngtonle

Cordia

Tournefortia

Figure 5 Vegetation of the islands from Teitai to Piliaieve, ui (after Woodroffe, 1985}.

VEOETA.TlON UNITS

~ "-mphlallCrub ~ D SeaevOla .crub D Pandanua grove C Seaevola f Acalypha .crub a Pulakepll Scaevole I A.celyphe IICrub with PIaonoe INDIVIDUAL TREES

~ seeevole f Acalypha .crub wIth aparse coconut

_ ToumelCKtiascrW Hemandla

EI] Pipturus I Aclllyphe I Seaevole .crub c.Jophylium

o Rhizophora scrub earrloglOOle lumnltzerll.cruo o ""'.~ g Coconut woodland ArtocarpYS [2] _..-"'" D Hemandll! woodland

500 metres

Figure 7 Vegetation of Fenua Tapu, Nui (after Woodmffe, 1985). '0 w

95 drinking nuts such as those areas close to the village on Fenua Tapu, while other areas may be harvested less frequently for copra production, and other areas may be entirely unattended and overgrown with scrub (Figure 9).

coconut palms exhibit great variations in height. In places, they are senescent palms which are poor in nut production, reaching up to 26 m tall. Monospecific coconut woodland is rare, ~d occurs only where regular clearance has been practised, a.s for instance in the area used for drinking nut collection around the village on Nui. Almost all plants are found within coconui woodland, and the coconut occurs in almost every other vegetation unit; the only vegetation types which do not mix with coconuts are the mangroves. The commonest understorey is scrub of Scaevola, or on the majority of atolls excepting Nukulaelae, Acalypha. coconut and Pisonia are often intermingled and Asplenium is often an important ground cover or epiphyte in such stands.

SCRUB Pemphis scrub Pemphis acidu/a (Ngie) forms dense thickets on many islands, particularly on the lagoonward shores of atolls and in comparatively sheltered inland locations on reef islands (see Figure 3). On Nui, Pemphis occurs either on the dissected conglomerate platforms of the reef islands (Figure 10), or on an infrequently inundated substrate of medium angular coral rubble or coarse sand. Along the lagoonward shore of the largest island, Fenua Tapu, Pemphis is 4-5 m tall, forming either a continuous fringe up to 30 m wide, or a discontinuous belt of individual shrubs. Similar scrub reaches 8-10 m tall on Tokinivae (Figure 11) and Pongalei. At Telaeleke on Fenua Tapu Pemphis scrub extends inland into a low-lying, infrequently inundated depression reaching to within 30 m of the oceanwaIti shore.

On Vaitupu particularly dense and impenetrable Pemphis scrub is found on the conglomerate platforms of the eastern shore of the island, where it is prominently wind-sheared rising from I m tall to the east to 5 m tall only 100m inland. A narrow, discontinuous fringe of Pemphis occurs around both the northern and southern lagoons, rarely exceeding 4 m tall and 5 m wide, though much has been cut or destroyed from the western and southern shores of the southern lagoon. A more extensive stand is found together with mangrove on the highly dissected supratidal flats to the southeast of the southern lagoon, and open Pemphis, associated with Thespesia, occurs in an area to the north of the southern lagoon.

97 Many of the stands of Pemphis are so dense that there are generally no other plants associated with it. Polypodium is found in some places within Pemphis scrub on NuL On other islands occasional inliers of Tournefortia and Scaevola, groun.d cover of Fimbristylis or Lepturus, and the creeper Cassytha may be found.

A sparser form of Pemphis scrub is found inland on several reef islands. A particularly extensive stand occurs in the interior of Pongalei, Nui, where a partially consolidated substrate of fIne coral rubble and sand covered with a black algal mat, supports only a sparse shrubby vegetation. Pemphis up to 2 m tall with individual shrubs spaced 4-5 m apart dominates the area, though with scattered shrubs of Scaevola and Tournefortia, and with abundant Cassytha (Figure 12). There is a ground cover of Fimbristylis, Nephrolepis and Asplenium.

A scrub composed of Pemphis is one of the major coastal scrub types of atolls in the PacifIc. It has been noted in the Cook Islands (Stoddart, 1975), Tokelau Islands (Parham, 1971), Kiribati (Luomala, 1953; Moul, 1957) and Marshall and Mariana Islands (Fosberg, 1960). It is more successful than other scrub on coarse sediment and dissected rocky substrates, especially at low elevations prone to occasional inundation. Scaevola scrub A dense scrub of Scaevola sericea (Ngasu) forms a fringe around the majority of sandy reef islands of Tuvalu and often merges landwards into inland scrub. It is particularly prominent along oceanward shores of reef islands where it characteristically forms a fringe 15-20 m wide, up to 4 m tall. This coastal 6ringe is often backed by coconut woodland, and individual coconuts overhang the Scaevola scrub (Figure 13).

Scaevola is a relatively rapidly growing shrub; a 20 m wide belt now colonises a recently formed ridge (since 1971) linking what was previously the island Tutupe to eastern Fenua Tapu, the largest island on Nui (Figure 14). Characteristically the fleshy branches of Scaevola, sometimes covered with creepers such as Cassytha or Canavalia, make the scrub penetrable only with diffIculty.

On many of the islands Scaevola scrub is monospecifIc. The only frequent ground cover is of the fleshy herb Euphorbia chamissonis; Triumfetta procUlJ'lbens does occur within this scrub on NuL In some places on Nui Tournefortia, Cordia, Pandanus and Guettarda emerge above the canopy. On Vaitupu the only extensive stand of pure Scaevola scrub occurs at the northeast of the island where there is a gradation in height from 1.5 m tall at seaward to 2-3 m tall 20 m inland and where Morinda, Ficus and Guettarda are emergent. Stands of Scaeyola scrub have been described from seaward shores on Funafuti by Hedley (1896), and from much of Nanumea by Chambers (1984).

99

Figurel 12 Sparse Pemphis scrub, with Scaevola, central Pongalei, NuLS 100

Scaevola scrub is also the dominant vegetation over much of the interior of many islands. It occurs beneath coconut woodland in areas from which it has not been cleared. Large areas of scrub predominantly of Sca.evola cover much of the area of reef islands not dominated by coconuts; thus on Nui, much of Fenua Tapu is covered by Scaevola scrub, and on Meang, there is a sparse Scaevola scrub covering a series of north-south ridges of fine angular coral rubble (Figure 15). While Scaevola is the dominant plant, in many places the scrub also contains abundant Acalypha; the principle emergent is Pandanus. Boerhavia, Fimbristylis, Nephrolepis and Polypodium are found as ground cover. Locally Tournefortia, Guettarda and Pisonia are important.

Similar Scaevola scrub is found on most sandy islands throughout the Pacific (Christophersen, 1927; Taylor, 1950; Fosberg, 1953). It is prominent in the Tokelau Islands (Parham, 1971), on Swains Island (Whistler, 1983), in Niue (Sykes, 1970), and on Onotoa, Kiribati (Moul; 1957). Tournefortia scrub The shrub TournefortlcJ argentea (Tausunu), also known by the synonyms Messerschmidia argentea and Argusia argentea, is a common component of coastal scrub in Tuvalu. However pure stands of Tournefortia are usually of rather limited extent compared with Pemphis or Scaevola scrub. Some small stands of Tournefortia were observed in Nui, particularly at the northern and southern ends of Pongalei, and along the western shore of Meang T ournefortia fonns a fringe reaching 6-81m tall and 15-25 m wide (Figure 16). This fonn of scrub is much more open and ~enetrab~ than the two preceding scrub types, consequently it is less -monospeclfic and mdlVlduals of Scaevola, Guettarda, Pandanus and coconut are frequent, as well as ground cover of Triumfetta and Boerhavia. Small pockets of Tournefortia scrub also occur inland; these are again rarely extensive and consist of only a few individuals although Tournefortia may occasionally reach the stature of a tree up to 17 m tall, as in central Meang, Nui.

Although Tournefortia .scrub is a recognisable unit in Tuvalu it is not as widespread or as well-developed as it can be on other islands in the Pac~fic . A distinct Tournefortia scrub is found on Aitutaki (Stoddart, 1975a) and Suwarro)\' Atoll (personal observation) in the Cook Islands. It fonns a facies in the Tokelau Islands (Parham, 1971) and is important where no coconut woodland has been introduced as on Puluwat and Gaferut in the Caroline Islands (Niering, 1961). It is the only vegetation type extending east through the Pacific as far as Ducie Atoll (Rehder and Randall, 1975).

03 Mangrove There are two species of mangroves that.are found in Tuvalu, Rhizophora stylosa (Tongo) and Lumnitzera littorea (Sangale). Of these Rhizophora is the more extensive fonning dense thickets, while Lumnitzera rarely fonns more than a few individual plants usually fringing the Rhizophora. The distribution of mangove on the atoll of Nui, the reef-top island of Vaitupu which has two restricted lagoons, and on Nanumanga which has an entirely land-locked interior lagoon is shown in Figure 17. Mangrove develops best in sheltered environments and is thus found in the sheltered southeastern corners of the lagoons of Nui, where it grows to about 4 m tall in a belt up to 40 m wide around the edge of the conglomerate platfonn at Telaeleke, Fenua Tapu, and in a similar setting in the southeastern corner of the southern lagoon and around the shoreline of the northern lagoon of Vaitupu. However, the most extensive mangrove stand is on the completely occluded reef-top island of Nanumanga.

The Rhizophora thicket on Vaitupu comprises a series of small stands in pockets of soft sandy sediment within depressions in the cemented and fretted rock of the area, totalling 6 ha. The trees rarely reach 6 m tall, but their dense growth together with the interwoven prop root system reaching 2 m from the ground makes the vegetation impenetrable. Despite the small nature of the stand, litterfall collections have shown that this particular stand is highly productive (777±93 g/m2/yr) and it presumably supports a unique ecosystem (Woodroffe and Moss, 1984; Woodroffe, 1988).

Pemphis is the principle associate of the ,mangrove (Figure 17). Lumnitzera is restricted to two small pockets neither larger than 20 m by 30 m and less than 5 m tall on Nui, and only on Niutao is it extensive. Tuvalu lies close to the easternmost limit of mangrove distribution in the Pacific. Although there are more than 20 mangrove taxa in Southeast Asia and northern Australia, the number of species attenuates rapidly across the Pacific, with the easternmost mangrove in Samoa, excepting some possibly introduced Rhizophora in the Society Islands (see Woodroffe, 1988). The small mangrove stands in Tuvalu are similar to the inland mangrove depressions which occur ·in the Marshall Islands where Sonneratia and Bruguiera are recorded in addition to Rhizophora and Lumnitzera (Fosberg, 1975). Other scrub types Several other scrub types deserve mention though they are not particularly widespread in Tuvalu (Appendix 3). Acalypha is a prominent element within much of the inland scrub of many of the Tuvalu islands. Generally it is not as prominent as Scaevola and fonns a secondary component of Scaevola scrub (Figure 18). However, on Nukufetau there are stands which are dominated by Acalypha. Pipturus similarly plays an important role in the inland scrub of a number of islands, rarely fonning a Pipturus scrub, except perhaps for a stand on 104

Figure 16 Coastal Tournefortia serub, western shore of Meang, Nui. Nanumea Niutao 6"S / - MansroYe ' Nanumanga D Pemphis ' Nu l \ Reef edge ' Valtupu fl Nukufetau i ' Funafuti \ O~ __~1km \ ThvaIv 1 Nukulaelae' ~. \ Nlulaklta D. 176"E 178" 180 $es' f)", Ii Nanumanga '\ t::3 lNui " {.i ~~ ')! \ ql: .. \, : Vaitupu l .' ~ \.,...... /

Figure 17 The disnibution of mangrove and Pemphis on !'lui, Vaitupu and Nanumanga. Si 106

Nanumea. However Pipturus grows up to 10 m tall and is emergent from the scrub on many of the islands of Nui (Figure 19). A Ficus scrub can be distinguished on Nanumea; elsewhere Ficus is an important though not dominant element of inland scrub. Similarly Morinda, which is also widespread thoughout the islands, forms a thicket up to 8 m tall at one loction to the east of Pongalei, Nui (Figure 20).

Several scrub areas were mapped as undifferentiated scrub because it was not possible to determine which species were dominant from the aerial photographs. Ground verification where this could be carried out usually resolved the issue, but in some cases scrub was a mixture of several species and could not be accommodated in the units described above. Mixed ScaevolatFournefonia scrub is common along sand shorelines of the larger reef islands. A Scaevola/Acalypha or Pipturus/Acalypha/Scaevola scrub inwhich Guettarda, Ficus, Pandanus and coconut are common, and ground cover of Polypodium, Asplenium, Nephrolepis and Pteris is found, occurs widely on Nui. ScaevolatFournefortia/Guettarda is the dominant scrub on Vaitupu, Guettarda playing a much more prominent role. Scaevola is generally the seaward species growing up to 2 m tall around much of the island, but reaching 3.5 m to the southwest and northwest; this is overhung by Tournefortia 4-5 m tall within which Guettarda 6-8 m tall and less frequent Pandanus 8-10 m tall are emergent. This entire sequence of coastal shrubs is generally no more than 10 m wide; the zonation reflects that observed on reef islands of Aitutaki, except that there the zonation is generally several hundred metres wide (Stoddart, 1975a).

BROADLEAF WOODLAND Pisonia woodland Woodland of Pisonia grandis (Pukavai) is particularly widespread on reef islands throughout Tuvalu, and represents' one of the natural vegetation types which must have been much more extensive before planting or encouragement of coconut woodland. It is often found in association with deposits of phosphate or phosphatic soil. Especially impressive stands of Pisonia woodland have been described from Unimai, southern Meang, and Te Kolokolo and near Telaeleke, Fenua Tapu, Nui (Woodroffe, 1985). Here the woodland is dominated by immense individuals of Pisonia reaching 22-24 m high and more than I min diameter. Acalypha is prominent in the understorey, with Ficus, Guettarda and Pandanus less abundant. The fern Asplenium is an important associate in Pisonia woodland, growing both on the ground, and epiphytically in the branches of the trees (Figure 21: 107

Figure 18 Scaevo/a/Aca/ypha scrub with coconut, Unimai, NuL 108

Figure 19 Pipturus/Aca[ypluJ/Scaevo[a scrub, with Tourneforcia, eastern Fenua Tapu, Nui. 109

Figure 20 Morinda thicket, Ponagiei, NuL 110

Even though Pisonia does not always reach such stature, small pockets of Pisonia woodland are common on reef islands thoughout Tuvalu. The tree manages to persist because of its abilitiy to coppice, and to shoot up from fallen limbs, such that attempts to fell it rarely lead to its total eradication from a site. Consequently Pisonia is also a common associate in other broadieaf woodland types.

The association of Pisonia with phosphatic soil has been observed widely in the Pacific (Fosberg, 1953), and is a feature also in Tuvalu, especially in Vaitupu where stands of Pisonia in the centre of the island are underlain by red crumbly phosphatic nodules. Pisonia differs from much of the rest of the vegetation of reef islands in that its seeds are sticky and are dispersed by birds, rather than being drift-dispersed. The tree (or associated Hernandia) is also frequently the nesting site for large numbers of birds, particularly fairy terns. Fosberg (1953) has suggested that the combination of bird guano, and acidic leaf litter beneath Pisonia contributes to the phosphatic nature of the soil.

Similar Pisonia woodland is typical of many atolls in the Pacific, i.e Tokelau Islands, Kiribati, Marshall and Caroline Islands (Parham, 1971; Moul, 1957; Marshall, 1975; Fosberg, 1990). It is almost monospecific on Vostok Island (Clapp and Sibley, 1971), and is associated with Hernandia on Aitutaki, Cook Islands (Stoddart, 1975). Hernandia woodland Woodland of Hernandia sonora (Puka) is less extensive than that of Pisonia, and appears in many cases to be less clearly natural. This relatively fast-growing tree is often used for canoe manufacture, and its valuable timber implies that many of the stands, particularly close to villages, have been planted. This applies to monospecific small stands of Hernandia found on Fenua Tapu, Nui (Figure 22), and may also be the case on Nanumanga. Elsewhere Hernandia is an important associate of Pisonia and mixed stands of the two are the most outstanding broadleaf woodland types of central Vaitupu, and on Nanumea (Chambers, 1984). Hernandia dominate an area of southeastern Vaitupu, east of the supratidal flats that fringe the southern lagoon. Here trees are 'Spaced 8 m apart and the canopy is 20 m or more high. Emergent Hernandia reach 26 m, and one felled tree, from which a can~ had been made, appeared to have been 30 m tall. Some Cordia is found in this stand, with Guettarda, Morinda, Ficus, and the ferns Asplenium, Polypodium and Nephrolepis. Hernandia are also found south of the lagoon on Vaitupu behind a fringe of Cordia and Thespesia, where they can reach more than 25 m tall; here they show evidence of having been regularly cut for timber.

l12

HeT1llJndia woodland is rarely identifiable as a discrete unit on other Pacific islands, more usuaIiy it is associated with Pisonia woodland, as on Aitutaki and in the Swain Islands (Stoddart, 1975; Whistler, 1983) CaJophylium woodland CaJophylium inophyllum (Fetau) is one of the biggest trees that grow in Tuvalu. Like HeT1llJndia, it is important for its timber, and it is difficult to decide to what extent groves of Calophyllum are naturaI or have been planted. It does not form as widespread a unit as Pisonia woodland, nevertheless it does form a distinct unit on several islands, including Fatato, Funafuti. Elsewhere it is mixed in with other large trees, as in the broadleaf woodland on Nanumea (Chambers, 1984). Calop,hyllum is more abundant on some other islands in the Pacific, such as the Lau Islands (Garnock-Jones, 1978). Pandanus woodland Small groves of Pandanus tectorius (Fala) occur around the coast of many of the reef islands of Tuvalu. They are generally composed of a few individuals of Pandanus, 8-10 m tall. Exceptionally, as on Fenua Tapu, Nui, Pandanus reaches to 18 m. Pandanus woodland is reported as a much more extensive vegetation unit in the Palau and Cook Islands (Gress itt, 1952: Stoddart, 1975).

DISCUSSION VEGETATION UNITS The vegetation units which have been described above and which have been mapped in detalI for Nui (Figs 3-7), and in similar but less detailed form for several of the other atolls (McLean et aI., 1985,1986a, 1986b, 1986c, 1986e; McLean and Hosking, 1986), have been discriminated largely from aerial photographs, and their recognition is based on structure and aerial photographic texture and tone. It is less clear whether objective phytosociological classification based on species composition would distinguish the same units.

In order to assess this, 21 sites on Nui were sl1fVeyed on a semi-quantitative basis (Figure 23). Species abundance was ranked on a scale of 1 - 5 (Dominant 5; Abundant 4; Common 3; Occasional 2; Rare 1); results are listed in Table I. Figure 23 shows a dendrogram using single linkage agglomerative cluster analysis using squared Euclidean distance. Broadleaf woodland, cQConut woodland and scrub can be discriminated. The greatest disturbance to vegetation has occurred on western Fenua Tapu. In particular the natural compositional variability of economically valuable broadleaf woodlands has been altered, and the Pisonia stand at Te Kolokolo (16), and the Hernandia stand nearer the village (17) are the least similar to all other sites examined. With these exceptions, vegetation units on the more remote

114

Table I Species composition of plots on Nui atoll. Tuvalu

I 2 3 4 5 6 7 8 9 10 11 12 13 14 IS 16 17 18 19 20 21

Artocarpus altitis I Calophyllum inophyllum 2 2 Cocos nucifera 2 3 3 524 5223 222 Cordia subcordala 2 I Guettarda speciosa 23 32322 323 2 Hernandia sonora 5 5 Pandanus tectorius (s.l.) 2 4 2 3 3 3 223 Pisonia grandis 5 2 4 4 3 5 2 4 I 5 4 Premna obtusifolia 2 Terminalia samoensis Ximenia americana I 1 Acalypha amentacea 344 344 4 4 3 3 4 3 433 3 Ficus tinctoria 2 3 233 2 2 3 2 3 3 5 332 Morinda citrifolia I 2 '1 I 2 3 4 3 3 Pipturus argenteus 2 2 4 4 3 3 454 Scaevola sericea 5 5 1 4 5 4 3 5 3 3 2 4 Tournefortia argentea 232 5 3 1 Achyranthes aspera 2 1 Boerhavia tetrandra 3 434 Laportea interrupta 1 Portulaca lutea Trium[ella procumbens 4 Asplenium nidus 3 4 4 3 2 3 4 5 253 Canavalia cathartica 3 3 2 4 Cassytha [iliformis 2 2 3 2 Fimbrisry/is cymosa 3 2 I 2 2 Ipomoea macrantha Lepturus repens 2 I 2 1 3 2 3 Nephrolepis aCUlifolia 2 2 223 4 2 3 4 234 3 2 Polypodium scolopendria 2 I 2 1 2 3 2 1 2 3 222 3 2 P teris tripartita 1 3 Stenotaphrum micran/hum Viana marina

and reef-top islands as these have emerged from below sea level in the mid- to late Holocene. what is of particular importance is not distance from Southeast Asia. but distance from a Pleistocene refuge. Some of the plants which were found on the Pleistocene limestone islands prior to their disappearance beneath the postglacially rising sea level. will be likely to have recolonised from nearby islands which were not submerged beneath Holocene seas. Islands which rise up several metres above present sea level. and on which there are rocks older than Holocene in age would thus have acted as refugia. and as a source of propagules for Holocene revegetation of the emerging atolls and reef-top islands. In the case of Tuvalu. Fiji may have been a source of some plants. though currents do not flow from Fiji to Tuvalu. Other islands 115

Figure 22 Hernandia woodland, central road, Fenua Tapu, NuL '"

1000 25 mel res

20

"(J 15 c: u;'" is 10 Q

5

o 16 17 2 20 19 • 12 5 II 8 I. 6 10 18 21 I 3 9 13 15 1 8, BII lito BtoIBII lito c c S. Spa,S... Spas Sue s... S&iII _ "" S,/S.. SIIS• Broadleaf . ~~ , c.> 0 Scrub Woodland , 0 0 ' U~

Figure 23 The location of twenty-one sites on Nui, and a dendrogram of those sit.es derived by cluster analysis. 81 a) All plants

.! 40 ~ 10 .,o i(/) T'T'''' ". '0 5 g ao o o Z 'I , 0 .0' 0 . 10 1.00 10.00 100.00 1000.00 ~ 2°1 10 ","b' . enIT' 5 • •• 0 .01 0. 10 1.00 10.00 100.0 0 '0 ~ 0 .0 1 0 :'0 1 ~ oo 1 o ~ oo 1 oo ~ oo 1000:00 40~ b) Native plants 2 0~ e) Herbs : 30 '- '0 "' ., . ~ 15 0. .. (/) 2 0 . : "0. '0 (/) 10 '0 ~ 10 o z

0.01 0 . 10 1.00 10.00 100.00 0 .01 0 . 10 1.00 10.00 100.00 1000.00 Area (hal Area (hal

Figure 24 a) tOlal number of species against logarithm of island area for the reef islands on Nui; b) number of native species against logarithm of island area for the reef islands on Nui; c) tree species agai nst logarithm of island area for the reef islands on Nui, showing the location of Vaitupu on the graph, based on reconnaissance survey; d) shrub species against logarithm of island area for the reef islands on Nui; e) herb species against logarithm of island area for the reef islands on Nui.

:::i 118 such as Ocean Island and Christmas Island in Kiribati, and Samoa, Society Islands, Marquesas and Solomon Islands are more probable sources.

In addition to remoteness there are further trends in vegetation diversity associated with climatic factors in the Pacific. Diversity tends to be greater where rainfall is higher. There may be further effects, such as the incidence of hurricanes, which may create conditions favourable for propagule establishment, or substrates which suit particular plants.

The especially strong species-area relationship on Nui, indicates that island area is .significantly related to diversity. One may ask whether such a trend is one that could be continued. If there were a larger island still as a part of Nui Atoll, would it be more diverse? Appendix 1 indicates that there are several species which occur in Tuvalu, but are not found on Nui.Vaitupu is a larger island, with a land area of around 5 km2 (largest island on Nui 138ha). Figure 24 shows the number of trees (the only group for which records in Appendix 1 can be considered exhaustive) for Vaitupu on the species-area plot for Nui. Artocarpus and Gardenia are excluded from this analysis as they are generally planted. Thespesia and Hibiscus are found on Vaitupu but not in Nui, whereas Ximenia appears to occur in Nui and not Vaitupu. It seems that there is still something of a regional pool, and thilt there are other species which could be expected on larger islands. There are, furthennore, plants which occur elsewhere on Pacific atolls which are not found in Tuvalu, suggesting that the species-area relationship could hold for larger atolls also (i.e. Timonius po/ygamus).

The regularity of the species-area relationship on Nui suggests that these islands are particularly balanced. This pattern contrasts' with the species-area relationship seen on some other small islands, such as Kapingamarangi, where diversity is relatively invariant with small size (Niering, 1963; MacArthur and Wilson, 1967). Islands less than lAha appeared to have little variation in species number, attributed on the one hand to ecological factors such as soil matuiity, freshwater lens development or protection from salt spray (Niering, 1963; Wiens, 1962; Whitehead and Jones, 1969), and on the other to the episodic instability of such islands (MacArthur and Wilson, 1967). Nui reef islands I1VlY be so much more in equilibrium because of the relative unifonnity of reef island substrate, the atoll-wide distribution and isodimensionality of islands, and the infrequency of catastrophic stonns (Woodroffe, 1986). The importance of stonns even on other islands in the Tuvalu chain has been demonstrated by the studies of the impact of, and recovery from Hurricane Bebe on Funafuti (e.g. Fitchett, 1987). 119 CONCLUSION The flora and vegetation of 'low' islands of the Pacific do not exhibit the diversity or the endemism apparent on the 'high ' islands. This must, in large measure, reflect the very young geological age (late Holocene) of the terresoial ecosystems of these low islands. Nevenheless, detailed mapping of the atolls and reef-top islands of Tuvalu demonstrates considerable variability in the disoibution of plants both within vegetation units on islands, within archipelagoes, and berween archipelagoes in the group. Study of these patterns can give us insights into the processes of plant dispersal and establishment which operate not only on these remote islands, but perhaps also in the formation and maintenance of 'habitat' islands in other continental vegetation formations.

ACKNOWLEDGEMENTS This work on the vegetation of Tuvalu was possible as a part of an FAO-UNDP Land Resources Survey of Tuvalu. I am panicularly grateful to Roger McLean, project co-ordinator, for the opportunity to panicipate in the project, and to Roger McLean, Peter Hosking and Paul Holthus for their considerable input into the vegetation mapping and description of the various islands. Bill Sykes, Ray Fosberg and the late Marie-Helene Sachet identified many of the specimens. My thanks to the island councils for their support and hospitality, and a particular thankyou to the people of Nui.

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Hedley, C. 1896. General account of the atoll of Funafuti. Memoirs of the Australian Museum 3, 1-71.

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124

Appendix 1 Plants of the atolls and reef-top islands of Tuvalu

Nma Nmg Nto Nui Vai Nft Fun NkI NIk

Trees

Artocarpus allilis (Park.) Fosb. Ce Sp Sp Cw Sw Sp Cm Cw Barringtonia asialica L. Ce Sp Cw Cw Sp Cm Cw Calophyllum inophyllum L. Ce Sp Sp Cw Cw Sp Cmh Cw Sp Cocos nucifera L. Ce Sp Sp Sw Sw Sp Ch Sw Cordia subcordata Lam. Ce Sp Sp Cw Cw Sp Cm Cw Gardenia laitensis DC. Ce Cw Cw Cmh Cw Gueltarda speciosa L. Ce Sp Sp Cw Cw Sp Cmh Cw Sp Hernandia sonora L. Ce Sp Sp Cw Cw Sp Cmh Cw Sp Hibiscus tiliaceus L. Ce Sw Cmh Sp Lumnitzera littorea (Jack) Voigt Sp Sp Cw Cw NeisospermJl Opposilifolia (Lam.) Fosb. & Sachet Ce Sp Sp Cw Cw Sp Cmh Cw Pandanus teclorius Parle (sJ.) Ce Sp Ck Sw Sw Sp Cmh Sw Sp Pisonia grandis R.Br. Ce Sp Sp Cw Cw Sp Cf Cw Sp Premna obtusifolia R.Br. Ce Sp Sp Cw Cw Sp Cmh Cw R hizophora stylosa Griff. Ce Sp Sp Cw Cw Sp Cmh Sp Tenninaiia calappa L. Cd Cf Tennina/ia samoensis Rech. Ce Cw Cw Cm Cw Thespesia populnea (L.) Correa Ce Sp Cw Sp Cmh Cw Ximenia americana L. Ce Cw

Shrubs

Acalypha amentacea Roxb. var. Ce Sp Sp Cw Cw Sp Cd Cw Clerotkndrum inerme (L.) Gaertn. Ce Cw Cw Cw Ficus linctoria Forst. Ce Sp Sp Cw Cw Sp Cmh Cw Morinda cilrifolia L. Ce Sp Sp Cw Cw Sp Cmh Cw Sp Pemphis acidula Forst Sp Sp Sp Cw Cw Sp Cmh Cw Sp Pipturus argenleus (Forst.) Wedd. Ce Sp Cw Cw Sp Cm Sp Procris peduncuJata (Forst.) Wedd. Cw Scaevola sericea Vah! Ce Sp Sp Cw Cw Sp Cmh Cw Sp Suriana maritima L. Cw Cw Cm Cw Tourne/ortia argentea L. Ce Sp Sp Cw Cw Sp Cmh Cw Sp

Herbs

Abuti/on indicum (L.) Sweet Chw Achyralllhes aspera L. Ce Ck Cw Cw Cm Achyralllhes canescens R.Br. Ce Adenoslemma lanceolalum Miq. Ck Cw Cm Alternanlhera sessi/is (L.) R.Br. Cw Cw Cd Cw Boerhavia repens L. Cw Boerhavia tetrandra Forst. Ce Sp Cw Cw Sp Cm Bo"eria verticillala (L.) Mey. Ce Cw Eclipla prostrala (L.) L. Cw EKphorbia atoto Forst. Ce Cd EKphorbia cha!7Ussonis (Kl. & Gke) Boiss. Ce Cw Cw Cw EKphorbia cyathophora Murr. Cw EKphorbia geniculala On. Cw 125

Euphorbia hirta L. Cw Cw Hedyotis romanzojJiensis (C & S) Fosb. Cc Cw Laportea interrupta (L.) Chew Cw Cw Laportea ruderalis (Forst) Chew Cc Cw Cm LlIdwigia octovalvis (Jacq.) Raven Cc Sp Sp Cw Cw Cm Cw Phyllanthus amarus Schum. Cc Cw Cw Cd Cw Physalis angulata L. Cc Cw Cd Cw Pi/ea microphylla (L.) Lieb. Cc Cw Cw Cd Cw Portulaca australis Emil. Cc Cw Cw Cw Portulaca I.. tea Sol. Cc Cw Rivina humilis L. Cfd Russelia equisetijormis Cham & Schlecht. Cc Cw Cw Sida rhombifolia L. Cmw Spermacoce assurgens Ruiz & Pay. Cw Triumfetta procumbens Forst. Cc Sp Cw Cw Sp Cmh Cw Vernonia cinerea (L.) Less. Cc Cw Cw Cw Wollastonia biflora (L.) DC. Cw Cmh

Ferns, Grasses, Sedges, Creepers

Asplenium nidus L. Cc Sp Sp Cw Cw Sp Cmh Cw Sp Canavalia cathartica Thou. Cc Sp .Cw Cd Sp Cm Cw Cassytha filiformis L. Cc Sp Cw Cw Sp Cm Cw Cenchrus echinatus L. Cc Cw Cw Cw Cyperus alternifolius L. Sw Cd Cyperus compressus L. Cc Cdw Eleocharis geniculata (L.) Room. & Schult. Cw Cw Eleusine indica (L.) Gaenn. Cc Cw Cw Cm Cw Eragrostis tenella (L.) Roem. & Schult. Cc Cw Cw Cm Cw Fimbristylis cymosa R.Br. Cc Sp Cw Cw Cdf Cw Fimbristylis dichotoma (L.) Vahl Cw Cf Cw Ipomoea macrantha Room. & Schult. Cc Sw Cw Cmh Cw Ipomoea pes-caprae (L.) R.Br. Cf Lepturus repens (Forst.) R.Br. Cc Ck Cw Cw Cm Cw Nephrolepis acutifolia (Desv.) Christ. Cc Sp Sp Cw Cw Sp Cf Cw Sp Nephrolepis exaltata (L.) Schott. Cmd Nephrolepis saligna Cass. Cw Cw Paspalum distichum L. Cw Cw Polypodium scolopendria Burm. Cc Sp Sp Cw Cw Sp Cmh Cw Sp Psi/otum nudum (L.) Beauv. Cc Cw Cw Cmh Cw Pteris tripartita Sw. Cw Cw Cm Stenotaphrum micranthum (Desv.) Hubb. Ck Cw Cw Cf Thuarea involuta (Forst.) R.Br. CW Cw Cw Vigna marina (Burm.) Merr. Cc Cw Cw Cf Cw

Key for Appendix 1: Nma = Nanumea Nmg = Nanumaga Nto = Niutao Nui = Nui Vai = Vaitupu Nft = Nukufetau Fun = Funafuti NId = N ukulaelae Nlk = Niulakita C = Collected S = Sight record m = Maiden d = Maddison h = Hedley f = Fitcheu c = Chambers w = Woodroffe p = Holthus/McLean/Hosking k = Koch

Note: Collections and sight records [rom many islands incomplete. Collections recorded in preference to sight records. Records from undeposited specimens of Maddison and Fitchett only where no other record known. 126

Appendix 2 Local Tuvalu names for plants

Tuvaluan name Name on Nui

AnocarpUS altilis Mei Mei Barringtonia asiatica Futu (Kafutu·) Ulu Calophylillm inophyl/um Fetau Itai Cocos nucifera Niu Niu Cordia subcordata Kanava Kanava Gardenia taitensis Tiale Siale Guettarda speciosa Pua Uli Hernandia sonora Puka (Pukavai·) Puka Hibiscus tiliaceus Fau (Fau tuu·) Lumnitzera littorea Sangale Tangali NeisospermLl oppositiJolia Fao Pau pau Pandanus tectorius Fala Teou, Teto Pisonia grandis Pukavai (Puka*) Pukavai Premno obrusifolia Aloalo Te ango Rhizophora stylosa Tongo, Togo Tongo Terminolia samoensis Talie Te ipe Thespesia populnea Milo Ximenia americana Talatalaamoa • Kanana Acalypha amentacea Ongongo (Kalakalaapuki*) Kakarapus Clerodendrum inerme Inato Inato Ficus tinetoria Felo Pelo Morinda cirrifolia Nonu Te non Piprurus argenteus Fau vau (Fau·) Te pau Procris pedunculata Vau vau Scaevola sericea Ngasu (Ngahu·) Ngahu Suriano maritima Ngiecool Ngie Tourneforria argentea Tausunu (Tauhunu*) Tausunu Achyranthes aspera Sisi vau Boerhavia tetrandra Kisi kisi (Kalihilihi*) LaPonea interrupta Luna (Aluna *) Triumfetta procumbens Tolotolo Kiaou Asplenium nidus Laukatafa, Laukatapa Laukatapa ( • Nanumea name (Chambers, 1984) 127

Appendix 3 Tuvalu vegetation units

Nma Nmg Nui Nft Nkl Vai Nto Fun

Coconut woodland C X X X X X X X x Pisonia woodland Bp X X X Hernandia woodland Bh X X X X X Calophyllum woodland Bca X X X X x Cordia woodland Bco X X Thespesia woodland Bt X X Neisosperma woodland Bo X X X x Guettarda woodland Bg X Pandanus woodland F X X X X x Pisonia and Hernandia woodland Bp/Bh X X X X Hernandia and Calophyllum woodland BhlBca X Neisosperma and Pisonia woodland Bo/Bp X Cordia and Thespesia woodland Bco/Bt X Undifferentiated broadleaf woodland Bu X X X X X Pemphis scrub Spe X X X X X x Scaevola scrub Ss X X X X X X X x Tournefortia scrub Sme X X X X x Acalypha scrub Sa X Pipturus scrub Spi X Ficus scrub Sf X Morinda scrub Smo X Scaevola and Tournefortia scrub Ss/Sme X X X Scaevola and Acalypha scrub .Ss/Sa X PipturuslAcalyphalScaevola scrub Spas X Pemphis and mixed scrub Spe/Su X undifferentiated scrub Su X X X X Coconut and Pisonia woodland C/Bp X X X x Coconut and Hernandia woodland C/Bh X X Coconut and Calophyllum woodland C/Bca X Coconut and Neisosperma woodland C/Bo X Coconut and undifferentiated woodland C/Bu X X X Scaevola, Acalypha and Pisonia Ssap X Pemphis, Cordia and mixed scrub Spcu X Guettarda and Pipturus Bg/Spi X Guettarda and Pandanus Bg/F X Scaevola and Pandanus Ss/F X X X X Scaevola and coconut Ss/C X Scaevola, Acalypha and coconut SsaC X Scaevola, Pandanus and coconut SsfC X X X Pemphis, coconut and mixed scrub SpuC X Mixed scrub and coconut Su/C X X X X X 128

Rhizophora woodland Mr X X X X X X x Lumnitzera woodland Ml X X X Rhizophora and Lumnitzera woodland Mr/Ml X Rhizophora and Pemphis woodland Mr{Spe X Dense creeper Lc X X Grass Lg X X X Nephrolepis and sparse scrub Ln X X Pulaka pit P X X X X X X X x

Key for Appendix 3: Nma = Nanumea Nmg = Nanumaga Nto = Niutao Nui = Nui Vai = Vaitupu Nft = Nukufetau Fun = Funafuti NkI = Nukulaelae N1k = Niulakita

Note: Vegetation mapping of Vaitupu based only on preliminary map drawn from 1:30,00Q photography. Funafuti not mapped and records derived only from casual observations on Fongafale and adjacent islands.