+ All Categories
Home > Documents > Plott Palm Trees Research Data v52n2p71-83

Plott Palm Trees Research Data v52n2p71-83

Date post: 10-Apr-2018
Category:
Upload: eric-plottpalmtreescom
View: 219 times
Download: 0 times
Share this document with a friend

of 13

Transcript
  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    1/13

    Invasive alien species are recognized to be oneof the major causes of biodiversity loss. Becauseof their long-term evolution in completeisolation, island biota are particularlyvulnerable to foreign biological invasions.

    Humans have intentionally introduced amajority of plant invaders as gardenornamentals. Public or private botanic gardens,some of them established for many centuriesin the tropics, for example the Jardin des

    Pamplemousses in the island of Mauritius in1729 or the Cinchona Botanical Garden in

    Jamaica in 1868, have constituted major entrypoints for a large number of non-native plants,some of which became invasive (for example

    the tree Litsea glutinosa and the vine Hiptagebenghalensis in Mauritius or the treePittosporumundulatum in Jamaica). Gardens still representcontinual sources of potential (or incipient)invasive plants.

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    71

    Time Bombs inGardens: InvasiveOrnamentalPalms in TropicalIslands, with

    Emphasis onFrench Polynesia(Pacific Ocean)and the

    Mascarenes(Indian Ocean)

    JEAN-YVES MEYERDlgation la Recherche

    B.P. 20981

    Papeete, Tahiti

    French Polynesia

    jean-

    [email protected]

    CHRISTOPHE LAVERGNEAssociation Palmeraie-

    Union

    Domaine de Palmahoutoff

    97432 Ravine des CabrisLa Runion

    France

    AND

    DONALD R. HODELUniversity of California

    P.O. Box 22255Los Angeles, California

    90022

    USA

    Although palms are much beloved handsome and striking components of tropical

    and subtropical gardens and landscapes, some species, like many other ornamental

    plants, are invasive and can pose a threat to native ecosystems if they escape

    cultivation.

    PALMS 52(2): 7183

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    2/13

    Some plant families are recognized as beingweedy because they contain a high numberof invasive species. Invasive legume trees(Fabaceae), such as Leucaena leucocephala,

    Acacia spp. or Prosopis spp., were widelyplanted for forestry and/or soil improvementin the past, and weedy grasses (Poaceae), such

    as Melinis minutiflora, were intentionallyintroduced as fodder or are accidentallyintroduced as contaminants. With the increaseof the ornamental plant trade and the recentdevelopment of the landscape industry (thegreen industry), new invasive families areemerging. For instance, several Acanthaceaespecies, which are popular garden plantsbecause of their showy and colorful flowersand bracts, are now being reported as invasivein Indo-Pacific tropical islands (Meyer and

    Lavergne 2004). The palm family (Arecaceae)has been regarded as under-represented interms of the relative number of invasivespecies. Indeed, there are only a few species (ca.12) which are reported to be widely naturalizedor invasive in tropical islands or countries (Tab.1).

    The objective of this paper is to inform privateand public botanical gardens, palm collectorsand hobbyists, horticulturists, gardeners andlandscapers of the risk of invasion posed by

    some introduced ornamental palms. Svenning(2002), who focused only on naturalized palmsin a secondary tropical forest in Panama, raisedthe issue that popular palms have the potentialto become problematic invasive species andrecommended that a world-wide list ofinvasive, non-native species be compiled.

    Herein, we listed the main naturalized andinvasive species in tropical or subtropicalcountries and islands based on our personalknowledge and field-observations, extensive

    literature survey and personal communi-cations of botanists, gardeners and palmcollectors. We focused on French Polynesia,especially the island of Tahiti (Society Islands),and the Mascarenes, especially La Runion andMauritius islands. Potential (or incipient)invasive palm species that might present a risk

    of becoming invasive in the near future arealso noted.

    Major documented invasive palms

    Twelve palm species are recognized as invasivein tropical regions and islands (Tab. 1),meaning they are well established in the wildaway from the original introduction sites, formdense clumps or stands excluding the nativevegetation and spread in primary (or native)or in secondary (or disturbed) forests.

    The African oil palm ( Elaeis guineensis) isspreading on Pohnpei (Federate States ofMicronesia) particularly on drier sites (Space &Falanruw 1999).

    The Chinese fan palm or fountain palm(Livistona chinensis) is considered invasive inBermuda (Kairo et al. 2003) and in Mauritiusand La Runion Islands (Moore & Guho 1984,Strahm 1993, 1999). It is naturalized in Florida(www.fleppc.org/list/05List.htm), in Hawaii(Wagner et al. 1990, 1999) where it spreads in

    ditches, stream beds, wet gulches and shadyunderstory of disturbed secondary forests (Starret al. 2003a) and on the east coast of NewCaledonia in riparian forest (MacKey 1985).

    The California fan palm (Washingtonia filifera)is considered invasive in Hawaii (Starr et al.2003b) and Australia in the Perth area (Husseyet al. 2007, Richardson et al. 2006), while theMexican fan palm (W. robusta) is cited asinvasive in Hawaii (Starr et al. 2003b) andFlorida (www.fleppc.org/list/05List. htm).

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    72

    1. Increase of thenumber of palm speciesintroduced to Mauritius(Mascarenes, IndianOcean) and Tahiti(French Polynesia, PacificOcean) during the lasttwo centuries (after BaasBecking 1950, Jacquier1960 and Nadeaud plantdatabase, version 1992,

    for Tahiti, Rouillard &Guho 1981-1985, 1999for Mauritius).

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    3/13

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    73

    Table1

    .Themajordocumentedinvasiveor

    widelynaturalizedpalmsintro

    picalislandsandcountries.

    Scientificname

    Origin

    InvadedRegion

    Sources

    Archontophoen

    ixalexandrae

    Queensland(Australia)

    Hawaii(PacificIs.)

    Wagneretal.1990,1999

    Archontophoen

    ixcunninghamiana

    EasternAustralia

    Brazil

    www.institutoho

    rus.org.br/download/fichas/

    Archontophoenix_cunninghamiana.htm

    Arecatriandra

    India,SE

    Asia

    Panama

    Svenning2002

    Elaeisguineens

    is

    WestAfrica

    Pohnpei(Pacific

    Is.),

    Space&Falanruw1999,www.issg.org/database/sp

    ecies/

    Brazil

    www.hear.org/pier/species/elaeis_guineensis.htm

    Heterospatheelata

    Philippines

    Guam(PacificIs

    .)

    Jones1995,Spac

    e&Falanruw1999

    www.hear.org/pier/reports/mreport.htm

    Livistonachine

    nsis

    Japan,Taiwan,

    LaRunion(Ind

    ian

    Moore&Guho

    1984,MacKey1985,Strahm

    RyukyuIs.

    OceanIs.),Hawaii,New

    1993,1999,Kair

    oetal.2003,Starretal.2003a

    Caledonia(Pacif

    icIs.),

    www.hear.org/starr/hiplants/reports/html/

    Florida(USA),Bermuda

    livistona_chinen

    sis.htm

    (CaribbeanIs.)

    http://plants.usd

    a.gov/java/profile?symbol=LICH3

    Nypafruticans

    SEAsia,India,

    Nigeria,Trinidad

    www.africanconservation.org/ncftemp/nipa.html

    SriLanka,

    (CaribbeanIs.)

    Kairoetal.2003

    Australia,

    Solomon

    Is.,Ryuky

    uIs.

    Phoenixdactylifera

    NorthAfrica&

    Fiji,NewCaledo

    nia

    Smith1979,Fuller1997,Lazaridesetal.1997,

    MiddleEast

    (PacificIs.),Australia

    MacKee1985,W

    atling2005,Husseyetal.2007

    Ptychospermamacarthurii

    NewGuin

    ea,

    Fiji(PacificIs.),Barbados

    Fuller1997,Kair

    oetal.2003,

    Australia

    (CaribbeanIs.),Panama

    Svenning2002,Watling2005

    Roystonearegia

    Cuba

    Panama

    Svenning2002

    Washingtoniafilifera

    California,Arizona,

    Hawaii(PacificIs.),

    Oppenheimer&

    Barlett2002,Starretal.2003b,

    Mexico

    Florida,Australia

    Lazaridesetal.1

    997,Husseyetal.2007

    www.hear.org/Pi

    er/species/washingtonia_f

    ilifera.h

    tm

    www.hear.org/Pi

    er/pdf/pohreports/washingtonia_

    spp.pdf

    Washingtoniarobusta

    Mexico

    Hawaii(PacificIs.),

    Oppenheimer&

    Barlett2002,Starretal.2003b

    Florida(USA)

    www.hear.org/Pi

    er/species/washingtonia_robusta.htm

    www.hear.org/Pi

    er/pdf/pohreports/washingtonia_

    spp.pdf

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    4/13

    The Sagisi palm (Heterospathe elata), which wasintroduced to Guam between 1900 and 1920,

    is spreading in ravines and slopes (Jones 1995,Space & Falanruw 1999).

    The MacArthur palm (Ptychospermamacarthurii) and the date palm (Phoenixdactylifera) are widely naturalized in Fiji (Smith1979, Watling 2005), the first species alongdrainages, fence lines and vacant lots in urbanareas and the second forming largepopulations of about 1000 adult trees in theNadi area and surrounding cane fields (Fuller1997). The MacArthur palm is also naturalized

    in Panama (Svenning 2002), Singapore (HsuanKeng et al. 1998) and the islands ofGuadeloupe and Martinique in the LesserAntilles (Delnatte 2003,) and is consideredinvasive in Barbados (Kairo et al. 2003). Thedate palm, planted around settlementsthroughout the arid zone of Western Australia,forms dense thickets by suckering and seedsspread by birds, affects water flow and displacesthe nativeLivistona alfredii (Hussey et al. 2007).

    The Alexander palm (Archontophoenix

    alexandrae) is naturalized in Hawaii in low-elevation mesic valleys (Wagner et al. 1990,1999, Lorence, pers. comm. 2007), while thebangalow palm ( A. cunninghamiana) isnaturalized in several regions of Brazil

    including submontane rain forest in RioGrande (www.institutohorus.org.br/download/

    fichas/Archontophoenix_cunninghamiana.htm).

    The Cuban royal palm (Roystonea regia) occursin high abundance in secondary forests ofPanama, where it is well naturalized in swampor lakeside forests, andAreca trianda sometimescompletely dominates the understory ofsecondary forests there (Svenning 2002).

    The nipa or mangrove palm (Nypa fruticans) inNigeria, which was introduced from Singaporein 1906, is currently displacing the native

    mangrove vegetation and impacting coastalplant communities (www.africanconservation.org/ncftemp/nipa.html). This species is alsoreported as naturalized in the island ofTrinidad (Kairo et al. 2003) and Panama.

    Naturalized and Invasive Alien Palms inFrench Polynesia (Pacific Ocean)

    Beside the coconut (Cocos nucifera), which isconsidered native or a Polynesian intro-duction, only three native palms have been

    recorded from the remote oceanic islands ofFrench Polynesia:Pritchardia vuylstekeana and P. pericularum, both reportedly from theTuamotu Archipelago, andPelagodoxa henryanain the Taipivai Valley on Nuku Hiva in the

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    74

    2. Seedlings ofLicuala grandisin the understory of lowland rainforest on the island of Tahaa, French Polynesia(photo: Jean-Yves Meyer).

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    5/13

    Marquesas Islands. Recently, Hodel visitedMakatea in the Tuamotus and was able toverify that the indigenous palm there wasP.mitiaroana, which heretofore was thought to beendemic to Mitiaro in the Cook Islands. Theorigin ofPelagodoxa henryana is still somewhatcontroversial because all its known locations

    in the Marquesas and in Melanesia (Vanuatuand the Solomon Islands) are at sites currentlyor known to have been inhabited in the past.

    About 108 species of non-native (or alien)palms were introduced to French Polynesiaduring the past century (Table 1). Nine specieswere planted in Tahiti from 1840 to 1890,including five by E. Raoul in the town ofPapeete in a botanical garden called JardinRaoul, which is now the Mamao Hospital.Harrison W. Smith introduced about 30 species

    in the 1920s to 1940s to his garden in Papeari,now the Jardin Botanique Harrison Smith(JBHS). Recently, more than 70 species havebeen introduced from 1970 to 1990 by MichelGurin, former director of the JBHS, andhobbyists, collectors and those in thelandscape industry. See Hodel (1982, 1993) foraccounts of cultivated palms in Tahiti.

    Twelve species of palms are sparingly or widelynaturalized in French Polynesia (Table 2).Meyer (1998) reported that the ruffled fanpalm or Vanuatu fan palm (Licuala grandis,locally called palmier-cuillre in Tahiti,which means spoon palm because of its largeleaves), was established in wet, low-elevation

    secondary forest in a valley on the island ofTahaa (Society Islands) (Fig. 2). In its nativerange of Vanuatu (San Cristobal and SantaCruz),L. grandis is known to be gregarious inshaded understory of rain forest and formsextensive colonies (Jones 1995, Whitmore1975). Introduced to Tahiti in 1930, it wascultivated since 1936 in the JBHS, where it iscurrently locally naturalized.

    Gurin observed the Lucuba palm (Dypsismadagascariensis) naturalized in wet, low-

    elevation secondary forests of the OpunohuValley, Moorea (Society Islands) in the 1980sfrom a 1971 introduction. More recently Meyerobserved this species naturalized in theVaianae and Maharepa valleys of Moorea upto 400 m elevation in secondary and wetprimary forests (Fig. 3). It is noteworthy thatthis species (under the name Chrysalidocarpuslucubensis) is also noted to be locallynaturalized in low-elevation rain forest inMauritius (Lorence & Sussman 1986) and in

    peripheral area of a secondary tropical forestin Panama (Svenning 2002).

    Gurin also noted that the African Oil palm(Elaeis guineensis) was naturalized in the lowelevation Fautaua Valley in Tahiti as early asthe 1970s. In 2005 Meyer observed it locallynaturalized in a wet secondary forest that wasonce a cultivated area in a deep valley on theisland of Raiatea (Society Islands).

    The small fleshy fruits (ca. 1 cm in diameter)ofDypsis madagascariensis andLicuala grandismight be dispersed over long distances byfrugivorous birds, such as the common myna(Acridotheres tristis), introduced in the early1900s in Tahiti and found at lower elevations,and the red-vented bulbul (Pycnonotus cafer),introduced in the 1970s and found at higherelevation (up to 2000 m), but also by theendemic fruit dovePtilinopus purpuratus, whichis a generalist frugivorous wild pigeon foundin mid-elevation rain forests in the SocietyIslands. Meyer observed red-vented bulbuls

    feeding on mature fruits ofL. grandis in themain town of Papeete. The larger fruits ofElaeisguineensis might be dispersed by alien rats orwild pigs, which are common in deep and wetvalleys of Tahiti and Raiatea.

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    75

    3. Dypsis madagascariensisnaturalized in mid-

    elevation rainforest on the island of Moorea, FrenchPolynesia (photo: Jean-Yves Meyer).

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    6/13

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    7/13

    (Delnatte 2003, Kairo et al. 2003); theMacArthur palm ( P. macarthurii), native to

    Queensland and New Guinea and also locallynaturalized on the island of Kauai in theHawaiian Islands (D. Lorence, pers. comm.2007); Heterospathe elata, from the westernPacific, with many seedlings and young plantsgrowing in the shaded understory of a Tahitianchestnut (Inocarpus fagifer) secondary wet forest(Fig. 4); the Taraw palm ( Livistona saribus),native to Southeast-Asia, which is also well-established in Panama (Svenning 2006); andthe Australian cabbage palm (L. australis) andOncosperma tigillarium (Hodel 1982).

    Whether these palms will spread into thesurrounding vegetation or stay confined in the

    JBHS is not known, but there is often a timelag between the date of introduction and thenaturalization event, and between naturali-zation and invasion in secondary or nativeforests. Nypa fruticans, introduced in JBHS in1928, is locally naturalized in the garden butwill not expand its distribution as suitableesturine habitat is scarce or lacking in FrenchPolynesia.

    Another species, Pinanga coronata, fromIndonesia and introduced around 1980, maypose a threat because seedlings and saplingshave been observed in the JBHS and in nearbyprivate gardens. It has naturalized in similar

    wet habitats in Fiji (Hodel, personalobservation), especially in ColoiSuva where it

    was introduced in a garden in the 1970s andis now spreading aggressively through theColoiSuva Forest Park (Watling 2005). Densestands of this palm species are observed in theLyon Arboretum in Hawaii (R. Baker, pers.comm. 2007). Seedlings ofP. coronata wererecently observed in secondary wet forest at450 m elevation in a gulch located under aresidential area of the north coast of Tahiti.

    The JBHS is also the source of some of the mostnotorious and aggressive invasive plants in

    French Polynesia. Introduced in 1937, thetropical American treeMiconia calvescens nowcovers more than 80,000 ha of secondary andnative wet forest, including endemic species-rich cloud forest (Meyer & Florence 1996). Theinvasive trumpet tree (Cecropia peltata), theAfrican tulip tree (Spathodea campanulata), andthe shoebutton ardisia (Ardisia elliptica) wereall first introduced to the JBHS in the 1920sand 1930s. Other species have recently shownfirst signs of invasion, including the liana

    Anodendron paniculatum, which was introduced

    in 1934 (Meyer in press).Alien Naturalized and Invasive Palms in theMascarenes (Indian Ocean)

    Thirteen native palm species are recognized inthe Mascarene Islands (Moore & Guho 1984).

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    77

    4. Heterospathe elatanaturalized in the shaded understory of a Tahitian chestnutInocarpus fagifersecondaryforest in the Jardin Botanique Harrison Smith in the island of Tahiti, French Polynesia (photo: Jean-YvesMeyer).

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    8/13

    A new endemic species, Acanthophoenixrousselii, was recently been described in LaRunion, andA. crinita was recognized to be anative species in the Mascarenes (Ludwig2006). The origin of A. rubra is stillcontroversial because all its known locationsin La Runion are at or near places of past or

    current human habitation or other activity,although in Mauritius wild populations arestill found in the southern part of the island.This species may have been introduced fromMauritius to La Runion in the past for itsmuch esteemed edible apical meristem, locallycalled choux palmiste.

    FiveHyophorbe species have been described inthe Mascarenes: one endemic to La Runion(H. indica), one to Rodrigues (H. verchaffeltii)and three from Mauritius (H. lagenicaulis, H.vaughanii and H. amaricaulis). The genus

    Latania is endemic to the Mascarenes, and eachisland has its own endemic species: L.lontaroides in La Runion, L. loddigesii inMauritius and L. verchaffeltii in Rodrigues.Tectiphiala ferox is endemic on Mauritius andis represented by fewer than 25 individuals inthe wild (Lavergne et al. 2007). Dictyospermaalbum is still common and currently cultivatedon the three islands.

    Among the 274 species of palms introduced tothe Mascarenes during the last three centuries,only 93 are still growing in the archipelago(Moore & Guho 1984, Rouillard & Guho19811985, 1999). Palm introductions to the

    Jardin des Pamplemousses in Mauritiusincluded 16 species by Fuse Aublet,Charpentier de Cossigny, Juge, Abb Rochonand Cr & Le Brasseur from 1754 to 1785;160 species by, Falquhar, Thompson, Duncan,Bojer and Cantley; 160 species from 1815 to1892; 39 species by Konig, Wieh, Regnard,

    Rouillard, Val Ory and the forestry service from1904 to 1964; and 22 species from othersources in the 1970s80s (Rouillard & Guho1999). Only 72 species are still growing in thisbotanical garden.

    The gardeners N. Bron and Jean-MarieRichard planted about 45 species in the JardindAcclimatation of La Runion from 1825 to1856. About 35 non-native palm species arestill growing in this botanical garden, nowcalled Jardin de ltat, located in the main

    town of Saint-Denis.According to Moore and Guho (1984), about15 palm species are widely cultivated asornamentals in La Runion and Mauritius.Nine of them are naturalized (Table 2),

    including an invasive species, the Chinese fanpalm Livistona chinensis. On Mauritius it iswidely naturalized in the secondary and thenative forests (Rouillard & Guho 1981-1985,1999; Strahm 1993, 1999) and in the southeastpart of La Runion it has spread in streambeds,shady understory of disturbed secondary

    forests, and in coastal areas (Fig. 5). Local landmanagers often mistake it for the endemicpalmsLatania spp.

    The Lucuba palm, Dypsis madagascariensis,which is a very old introduction in Mauritius(1768), is naturalized in mid-elevation wetforests of Bel Ombre (J.-C. Sevathian, pers.comm. 2006). Seedlings and saplings of thegolden cane palmD. lutescens, a very popularpalm used for hedges in the gardens ofMauritius and La Runion, have been observed

    in a streambed near Saint-Leu (J. Hivert and C.Fontaine, pers. comm. 2006). Frugivorous birdsor water have probably dispersed the fruitsfrom a garden down to the valley bottom.

    The cabbage palm or West Indian royal palm,Roystonea oleracea, often planted in rows asavenue trees, is naturalized in La Runionaround the Saint-Paul pond and on a cliff neara waterfall. This large palm is also reported tobe naturalized in the Province Sud of NewCaledonia (MacKey 1985) where it forms smallpopulations, especially in the valley ofMoindou near a river (R. Amice, pers. comm.2007). It is naturalized in Guyana, Surinamand French Guiana (Zona 1996) where animportant population is found near the villageof Kaw (C. Delnatte, pers. comm. 2007).

    Members of Palmeraie-Union, a local palmamateur group, reported that a population 50individuals of Raphia farinifera, native totropical Africa and north and east Madagascar,is established in La Runion along the RivireSaint-Louis (Martz & Martz 2001). The botanistE. Jacob de Cordemoy (1895) also observedthis species naturalized along the streams ofBras-Panon in La Runion in the 19th century.However some Raphia populations haveregressed because of increasing urbanization.It is also naturalized along many streams andriverbanks in Mauritius, particularly aroundMare aux Vacoas and Moka plain (Rouillard &Guho 19811985, 1999), and is considered apotential invasive palm in the Seychelles

    (Dunlop et al. 2005).The date palm, Phoenix dactylifera, is widelyplanted along roadsides on the leeward coastsof Mauritius and La Runion. It is naturalizedin the driest region, particularly around Port

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    78

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    9/13

    Louis in Mauritius and on the leeward coast ofLa Runion (Cordemoy 1895). It can beencountered near Saint-Leu along the Ravinedes Poux in a remnant native dry forest(Lavergne, personal observation). The wild datepalm, P. sylvestris from southern and easternAsia is locally naturalized in Mauritius near

    Port Louis (Rouillard & Guho 19811985,1999).

    The queen palm, Syagrus romanzoffiana, isreported to be sub-spontaneous at the base ofMontagne Ory in Mauritius (Rouillard &Guho 1981-1985, 1999). The Mexican fanpalm, Washingtonia robusta, is locallynaturalized in Saint-Gilles, La Runion on aroadside near a plant nursery. According to A.Hoarau (pers. comm. 2005), a palm collectorin La Runion, this species could become a

    serious plant invader as it produces small fruitseasily dispersed by the Indian myna,

    Acridotheres tristis, or the red-whiskered bulbul,Pycnonotus jocosus, two widespread non-nativebirds in the Mascarenes.

    Discussion

    Only a few introduced palm species arenaturalized in French Polynesia (12 out of 108introduced species, ca. 12%) and in La RunionIsland (9 out of 93 species, ca. 10 %). It is also

    the case in Fiji (Pacific Ocean), which has morethan 100 palm species in cultivation but onlyfour documented naturalized species (Fuller1997, Watling 2005), and Hawaii with morethan 650 species of palms cultivated inbotanical gardens including four well-documented invasive species (Staples & Herbst2005).

    However, we predict that more and morespecies will become naturalized and invasivein French Polynesia and the Mascarenes in the

    near future, and more generally in tropicalislands worldwide as they are becoming verypopular landscape and garden plants. Thenumber of introduced species in these islandshas dramatically increased in the last decades(Fig. 1). Also, an increase in the number ofindividuals per species, in the number oflocalities where they are planted (whichtogether constitute the propagule pressureconcept) and potential suitable habitat fortheir establishment and naturalizationenhance the risk of invasion. Moreover, severalpalm species with small fruits (Ptychospermamacarthurii in Fiji [Watling 2005], Licuala

    grandis andDypsis madagascariensis in Tahiti,Washingtonia robusta in La Runion) areactively dispersed by alien frugivorous birds,

    especially mynas (Acridotheres tristis in manytropical islands, and A. fuscus in Fiji) thebulbuls (Pycnonotus caferandP. jocosus), overlong distances.

    Indeed, several species have recently escapedfrom cultivation to become naturalized inHawaii, including the cascade or cataract palm(Chamaedora cataractarum) (Staples & Herbst

    2005), the West Indian royal palm (Roystoneaoleracea) and the wild date palm (Phoenixsylvestris), which has formed locally extensivestands in mesic habitats in Hawaii (Hodel,personal observation).

    The Auckland Regional Council of NewZealand has recently planned to add threepalm species in its list of 119 banned invasiveplants: the bangalow palm (Archontophoenixcunninghamiana), the Chinese windmill palm(Trachycarpus fortunei) and the Canary Islanddate palm (Phoenix canariensis), because theyare spreading in the wild (www.arc.govt.nz/arc/). The two last species are alsonaturalized in disturbed areas in the region ofVictoria, Australia (Groves & Hosking 1997,

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    79

    5. Livistona chinensisnaturalized in coastal secondary

    forest of Saint-Philippe, La Runion, Mascarenes(photo: Christophe Lavergne).

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    10/13

    Lazarides et al. 1997). The Canary Island datepalm, which is widely planted as anornamental and a street tree, has started tospread along waterways across south-eastAustralia (Richardson et al. 2006).

    The Senegal date palm (Phoenix reclinata), the

    queen palm (Syagrus romanzoffiana), thesolitaire palm (Ptychosperma elegans) and thebamboo palm (Chamaedorea seifrizii) arereported to be naturalized in Florida(www.fleppc.org/list/05List.htm). The Senegaldate palm, native to tropical Africa, is reportedto be naturalized in Bermuda (Kairo et al.2003). Doubts persist on the origin ofPhoenixreclinata in the Comoros archipelago. It couldbe native, but it is more frequent aroundvillages and cultivated areas (Pascal 2000) andin coastal forests. However, the fruits are

    dispersed by the native lemurs, and the palmpopulations are increasing in the inland forestin the last ten years (N. Ludwig, pers. comm.2006). The queen palm, native to Brazil andArgentina, is also naturalized in the New SouthWales and southern Queensland region ofAustralia, the latter in urban shrubland in thesuburbs of Brisbane (Csurhes & Edwards 1998).

    Hyphaene thebaica, native from west tropicalAfrica to Egypt and the Arabian peninsula, isreported as a potential invasive palm inCuraao in the West Indies (Delnatte 2003).The rattan, Calamus caesius, a climbing, vine-like, spiny species native to Southeast Asia, isreported to have started to naturalize on theisland of Upolu, Western Samoa in the SouthPacific where it was intentionally introducedin the early 1990s (Mark J. Bonin, pers. comm.2007). The clustered fishtail palm Caryota mitisand the African oil palm Elaeis guineensis arenaturalized and considered moderatelyinvasive on the island of Mayotte in the

    Comoros archipelago, Indian Ocean (F.Barthelat, pers. comm. 2006).

    Other naturalizing palms in botanical gardensinclude the Sugar palm Arenga pinnata and

    Aiphanes horrida in the Amani Botanic Gardenlocated in the East Usambara Mountains ofTanzania, first established in 1902 (W. Dawson,pers. comm. 2007).

    Management of invasive species begins withprevention, early detection and rapid response(e.g. eradication) because control of largeinfestations is often very expensive anddifficult. Black lists of noxious (or harmful)species and Weed Risk Assessment (WRA)systems are now commonly used in Australiaand New Zealand to prevent introduction of

    potentially invasive species. WRAs are mainlybased on climate matches and life history traitsof species, and their behavior or invasivehistory elsewhere in the world (i.e. black listedspecies), but published information on manyplants species in specific regions or countriesare often lacking or not easily available, often

    being only found in gray literature.For example, the WRA for Hawaii and PacificIslands (www.botany.hawaii.edu/faculty/daehler/WRA/, version January 2007) evaluatesonly a relatively few number of palm species(64, but some of these are synonyms)including 10 cited in our study. Three of them(Ptychosperma macarthurii, Washingtonia filiferaand W. robusta) are considered invasive,causing significant ecological or economicharm in Hawaii.

    Three other species (Archontophoenix alexandrae[syn. Ptychosperma alexandrae], Ptychospermaelegans [syn. Seaforthia elegans] and Livistonachinensis), which are considered invasive inour study, need further evaluation accordingto the WRA because of important missingdata or because the species possesses acombination of traits that makes its behaviordifficult to assess.

    Four other species (Archontophoenix

    cunninghamiana, Dypsis lutescens, Roystonearegia and Syagrus romanzoffiana) are considerednot currently recognized as invasive in Hawaiiand not likely to have major ecological oreconomical impact on other Pacific Islands bythis WRA system. However, two of these arereported and known as invasive (D. lutescensand R. regia), and the other two are alreadynaturalized in tropical regions or islands (A.cunninghamiana and S. romanzoffiana).

    We strongly recommend avoiding the

    introduction and planting of the 12 well-documented invasive species (Table 1) and thetwo widely naturalized species in FrenchPolynesia and the Mascarene Islands (Table 2)that are able to form dense stands excludingthe native vegetation, as well as the otherlocally naturalized species in tropical islands orregions, which constitute real time bombsthat can escaped from cultivation and gardensand invade native habitats (dry and mesicforests, rain forests, riparian forests) in the nearfuture. By forming very dense stands orclumps, palm species have the potential todisplace native plant communities and changethe functioning of natural ecosystems (lightor water regime, soil nutrients). Remoteoceanic islands with a disharmonic flora might

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    80

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    11/13

    be more vulnerable to invasion by palms asthis functional group is scarce (only one genusin Hawaii, Pitchardia, and two in FrenchPolynesiaPritchardia andPelagodoxa) whereasdwarf, understory, climbing and clonal palmsare common in continental rainforests(Denslow 2003).

    In 1990, Hodel, alarmed by John Dransfieldsobservation that the Wanga palm, Pigafettaelata (asP. filaris) was a colonizer of disturbedareas in its native range of Sulawesi, cut downthe staminate tree he had planted to eliminateseed production and any possibilities of itsescaping from cultivation and becomingnaturalized in Tahiti (Hodel 1993). Theeradication ofDypsis madagascariensis in theisland of Moorea (French Polynesia) still seemspossible before dense stands are formed or

    before individuals are found at higherelevation and on steep slopes.

    In 1999, Meyer officially advised theDepartment of the Environment of FrenchPolynesia to ban introduction ofLicuala

    grandis, Washingtonia spp. andElaeis guineensis.All new importation of palms of the genera

    Adonidia, Areca, Arenga, Borassus, Dypsis,Corypha, Howea, Livistona, Ptychosperma and

    Roystonea, as well as Elaeis guinensis,Washingtonia robusta and Phoenix dactylifera,

    are officially illegal in French Polynesia (DecreeN276 CM 23 May 2005), primarily becauseof the risk of disease to the coconut, the mosteconomically important plant of the islands.

    More recently, 421 additional palm speciesbelonging to 130 genera and representingmore than 51,000 individuals have beenofficially introduced from 2000 to 2006 to LaRunion for a Palm Botanical Garden projectcarried out by the Commune du Tampon (A.Hoarau, pers. comm. 2007). A careful screening

    of all these species, currently cultivated in aplant nursery, should be conducted beforeplanting them out. Gardeners, horticulturistsand landscapers could become key allies in theprevention and control of invasive alien plantsin tropical islands, thus preserving their uniquebiodiversity.

    Acknowledgments

    We deeply thank Rmy Amice (Direction desAffaires Alimentaires, Vtrinaires et Rurales,Nouma, New Caledonia), Fabien Barthelat(Direction de lAgriculture et de la Fort,Mamoudzou, Mayotte), Mark J. Bonin(Samoan National Invasives Task Team, Apia,Western Samoa), Csar Delnatte (Herbier deGuyane, Cayenne, French Guiana), Wayne

    Dawson (University of Aberdeen, UK), MichelGurin (former director of the JardinBotanique Harrison Smith in Papeari, Tahiti,French Polynesia), Jean Hivert & ChristianFontaine (Conservatoire Botanique Nationalde Mascarin, Saint-Leu, La Runion), AlainHoarau (Palmito Palm Nursery, La Runion),

    David H. Lorence (National Tropical BotanicalGarden, Lawai, Hawaii, USA), Ray Baker (LyonArboretum, Honolulu, Hawaii, USA), NicoleLudwig (Palmeraie-Union Association, Etang-Sal, La Runion) and Jean-Claude Sevathian(Mauritius Wildlife Foundation, Vacoa,Mauritius) for their personal communicationsand often unpublished data on naturalizedpalms in tropical islands worldwide.

    LITERATURE CITED

    BAAS

    BECKING

    , L.G.M. 1950. Liste prliminairede plantes introduites Tahiti. Commissiondu Pacifique Sud, Document Technique N7,Nouma, 20 pp.

    CORDEMOY, E.J. DE 1895. Flore de lle de laRunion. Paul Klincksieck, Paris, 574 pp.

    CSURHES, S. AND R. EDWARDS. 1998. PotentialEnvironmental Weeds in Australia.Environment Australia, Biodiversity Group,Canberra, 208 pp.

    DELNATTE, C. 2003. La Guadeloupe face aux

    espces allochtones. Etude pralabledvaluation de la menace des espcesvgtales invasives dans le Parc National deGuadeloupe. DESS Ressources Naturelles etEnvironnement, Universit de Metz.Unpublished thesis,189 pp.

    DENSLOW, J.S. 1998. Weeds in paradise:thoughts on the invisibility of tropicalislands. Ann. Missouri Bot. Gard. 90:119127.

    DUNLOP, E., J. HARDCASTLE AND N.J. JIVAN SHAH.

    2005. Cousin and Cousine Islands. Statusand management of alien invasive species.Nature Seychelles, Victoria. Unpublishedreport, 65 pp.

    FULLER, D. 1997. Conservation Status, Diversityand Systematics of the Indigenous Palms ofFiji. University of the South Pacific, Suva,Fiji, Unpublished MSc. thesis, 152 pp.

    GROVES, R.H. AND J.R. HOSKING. 1997. Recentincursions of weeds in Australia 19711995.Technical Series N3, CRC for Weed

    Management Systems, Australia, Adelade,74 pp.

    HODEL, D.R. 1982. Cultivated palms in Tahitiand The Jardin Botanique de Papeari.Principes 26: 7785.

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    81

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    12/13

    HODEL, D.R. 1993. The growth of some palmsin Tahiti. Principes 37: 127138.

    HSUAN KENG CHIN, S.C. AND H.T.W. TAN. 1998.The Concise Flora of Singapore. Volume II:Monocotyledons. Singapore University Press,National Park Board, Singapore, 215 pp.

    HUSSEY, B.M.J., G.J. KEIGHERY, J. DODD, S.G.LLOYD AND R.D. COUSENS. 2007. WesternWeeds. Second Edition. The Weeds Societyof Western Australia (Inc.), Perth, 294 pp.

    JACQUIER, H. 1960. Enumration des plantesintroduites Tahiti depuis la dcouvertejusquen 1885. Bull. Soc. Etud. Ocan. 130:117146.

    JONES, D.L. 1995. Palms Throughout the World.Smithsonian Institution Press, Washington,

    DC., 410 pp.KAIRO, M.A.B., O. CHEESMAN, K. HAYSOM AND S.MURPHY. 2003. Invasive Species Threats inthe Caribbean Region. CAB International,Trinidad & Tobago. Unpublished report tothe Nature Conservancy, 132 pp.

    LAVERGNE, C., C. DURET, L. GIGORD, L. GROSSETAND L. REICHSTEINER 2007. Les palmiersmenacs de lIle Maurice et de ses lots (22mars2 avril 2006). Association Palmeraie-Union, La Runion. Unpublished report, 36

    pp.LAVERGNE, R. 2001. Plantes du Jardin

    dAcclimatation: mise jour de lanomenclature utilise au sicle dernier parles deux jardiniers-botanistes dans leurscatalogues: Nicolas Bron en 1825 et Jean-Marie Richard en 1856. Unpublished report,109 pp.

    LAZARIDES, M., K. COWLEY AND P. HOHNEN. 1997.CSIRO Handbook of Australian Weeds.CSIRO, Canberra, 264 pp.

    LORENCE, D.H. AND R.W. SUSSMAN. 1986. Exoticspecies invasion into Mauritius wet forestremnants. J. Trop. Ecol. 2: 147-162.

    LUDWIG, N. 2006.Acanthophoenix in Runion,Mascarene Islands. Palms 50: 8298.

    MACKEE, H.S. 1985. Les plantes introduites etcultives en Nouvelle-Caldonie. MusumNational dHistoire Naturelle, Laboratoire dePhanrogamie, Paris, 159 pp.

    MARTZ, C. AND B. MARTZ. 2003. Les Raphiafarinifera de la Rivire Saint-Louis. Magazinede Palmeraie-Union Latania 5: 1011.

    MEYER, J.-Y. AND J. FLORENCE. 1996. Tahitisnative flora endangered by the invasion of

    Miconia calvescens DC. (Melastomataceae). J.Biogeography 23: 775781.

    MEYER, J.-Y. 1998. Mcanismes et gestion desinvasions biologiques par des plantesintroduites dans des forts naturelles Hawaii et en Polynsie franaise : une tude

    de cas. Rapport dtude post-doctorale,Dlgation la Recherche, Papeete.Unpublished post-doctoral report, 72 pp.

    MEYER, J.-Y. In press. The snake-like climber Anodendron paniculatum (Apocynaceae), anew invasive liana in the rainforests ofTahiti (Pacific Ocean). Aliens (IUCN/ISSG).

    MEYER, J.-Y. AND C. LAVERGNE. 2004. Beautsfatales: Acanthaceae species as invasive alienplants on tropical Indo-Pacific Islands.

    Diversity & Distrib. 10: 333347.MOORE, H.E., JR. AND L.J. GUHO. 1984. Famille

    189. Palmiers. In: T.L. BOSSER, J. CADET, J.GUHO AND W. MARAIS (eds.), Flore desMascareignes. The Sugar Industry ResearchInstitute, Mauritius, ORSTOM, Paris, and theRoyal Botanic Gardens, Kew.

    OPPENHEIMER, H.L. AND R.T. BARLETT. 2002. Newplant records from the main HawaiianIslands. In: N.L. EVENHUIS AND L.G. ELDREDGE(eds.), Records of the Hawaii Biological

    Survey for 2000. Part 2: Notes. Bishop Mus.Occas. Papers 69:114.

    RICHARDSON, F.J., R.G. RICHARDSON AND R.C.H.SHEPHERD. 2006. Weeds of the South-East. AnIdentification Guide for Australia. R. G. andF. J. Richardson, Meredith, 438 pp.

    ROUILLARD, G. AND J. GUHO. 19811985.Histoire des Plantes dIntrt Horticole,Mdicale et Economique lIle Maurice 1.Henry & Cie, Lte, Les Pailles, 289 pp.

    ROUILLARD, G. AND J. GUHO. Eds 1999. LesPlantes et leur Histoire lIle Maurice. MSMLtd., Port-Louis, 752 pp.

    SMITH, A.C. 1979. Flora Vitiensis Nova. A NewFlora of Fiji, Vol. 1. Pacific Tropical BotanicalGarden, Lawai, 495 pp.

    SPACE, J.C. AND M. FALANRUW. 1999.Observations on invasive plant species inMicronesia. USDA Forest Service, Honolulu.Report to the Pacific Islands Committee,

    Council of Western State Foresters. USDAForest Service, Honolulu. 32 pp.

    STAPLES, G.W. AND D.R. HERBST. 2005. A TropicalGarden Flora. Plants cultivated in theHawaiian Islands and in other tropical

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    82

  • 8/8/2019 Plott Palm Trees Research Data v52n2p71-83

    13/13

    islands. Bishop Museum Press, Honolulu,908 pp.

    STARR, F., K. STARR AND L. LOOPE. 2003a.Livistonachinensis. Chinese fan palm, Arecaceae.USGS-BRD, Haleakala Field Station, Maui,Hawaii. Unpublished report, 4 pp.

    STARR, F., K. STARR AND L. LOOPE. 2003b.Washingtonia spp. Mexican fan palm andCalifornia fan palm, Arecaceae. USGS-BRD,Haleakala Field Station, Maui, Hawaii.Unpublished report, 5 pp.

    STRAHM, W. 1993. The conservation andrestoration of the flora of Mauritius andRodrigues. University of Reading.Unpublished PhD thesis, 240 pp.

    STRAHM, W. 1999. Invasive species in Mauritius:

    examining the past and charting the future,pp. 325347 In: O.T. SANDLUNG, P. SCHEI ANDA. VIKEN. (eds), Invasive Species and Bio-

    diversity Management. Kluwer AcademicPublishers, Dordrecht, 448 pp.

    SVENNING, J.-C. 2002. Non-native ornamentalpalms invade a secondary tropical forest inPanama. Palms 46: 8186.

    WAGNER, W.L., D.R. HERBST AND S.H. SOHMER.1990. Manual of the Flowering Plants ofHawaii. Volume 2. University of HawaiiPress, Bishop Museum Press, Honolulu:9891853.

    WATLING, D. 2005. Palms of the Fiji Islands.Environmental Consultants, Fiji. Ltd. 192pp.

    WHITMORE, T.C. 1973. Palms of Malaya. OxfordUniversity Press, London, 148 pp.

    ZONA, S. 1996.Roystonea (Arecaceae: Arecoid-eae). Fl. Neotrop. Monogr. 71: 136.

    PALMS Meyer et al.: Invasive Palms Vol. 52(2) 2008

    83

    Palm seeds. More than 750 species in catalog.

    Cycads.We can get 150 different species.

    All kinds of seeds. Collected in 45 countries. Nurseries and collectors.Worldwide.

    What seeds are you looking for?

    [email protected] www.amazonia-online.com


Recommended