HQ/nnirnl JO~ ' ~nl '!! 11" f.lU(/lN SlKitlJ ( 1987). 95: 155- 179 Invading plants at high altitudes on Tenerife especiaUy in the Teide National Park J. H. OI CKSON, r .L.S. Botally Department, Tite Ullivusity ofGtasgow G/2 8QQ J. C. ROORICUEZ AND A.MAC HADO ICONA. Sall/(1 Gru~ de T elluije, Gmwry ' stallds DlCKSON. J. H .. RODRI CIJEZ. J. C. & ~ I ACHAOO , A., 1986. lDv:lldial pllu.t. a t hil ta a1utudo o", Tan,rife, especi.Uy ia lb., T¿de Nauonal Parlo. F.ight)"'lhrtt Oo..-rring pl anl5 are' discussro aS succnsful. f"i la! or potential invaden of the Teidt· Nat;onal I'ark . Tencrifc. a caldera a. 2000 ni altitudc aud al>O\'e with a largel)" r lHkl11ic na.i\"( nora. T ..-o iml'0rla1ll melhoos of iu, ·; t ~ iv n arto considered . Fi l"$t ly. there "'as d i~lX'r'!IlI l by pastor:tl;sm, goa•• hcrd iug. au ande'll Vl':I.rtirr ... hieh slo l/11n! owr 30 )'e:al"$ ago. Sccondly. Ih e d ~\' dopm e:U1 of mass lournm in ,he: 1;lIt 25 )'ean has brought a rrrsh innuJ< or alien plaUIlI. Man)' or Ihe: 83 in\'adrn di :l(" u~ ha,'e: had onl)' Il':I.nsieUI oceurre:uccs. bUllO arto ",cll-nlablishrd. 15 bci ng gr:usc:s among whieh II,e... s fn:1"",,,, aud l'ulpin mJ~'eJ arto th e 1ll11$1 ahundant, CIr(n~potIi "m I'~h-M in and P IJII p,nlmsiJ ar~ ue'" to Te:uaire ;... d On(!JIi¡ tfO ", rrll/~ suo.p. Ir;SpnR;(Q i. ne ... 10 Ihe C,m:lI')" !sland •. Co'l' rol n":aJ,,rn are oUl lilll:« . Allrnl )lU han' alre:ad y l:>r" u mad,' 10 rolllain AIJnlIl bll,ba/II , /ArIM{tl snriolll a"d CJltwopnJ;~", slltt;n. .... I)I) IT IONAI. IU;YWORI)S: AI;ell planlS - colI ..n ·¡¡tÍQ" l1Iea$urcs - disjX'n.a1 - TeurTire: t'lo .... CONTt;NTS l"uOO"rl;on . J55 Calalogue ofin\'ading 5p«;(:s Origill$. di!iIX'TS.l 1 ,,,,ti IlItlUJ of.he iU\,:I(ling sl:>rdrs . 171'" Conlrol "rthe in\'3ding ' l't'Ól'S and cOIIst'r"alion 176 A ckno", lt:d ge: m ~ nt.s 177 Rcfcrtoncn. 177 IN'I'ROI)UCTION The caldera of Las Cañadas al altitudes of 2000 In (6500 rt ) and abovc, has long bccn renow ned for ilS distinctivc nora consisting largcl y of cnd cmi c specics (Bramwcll & Bramwe ll , 19 74; l\'lachado, 19 79 a; Ortuño, 1980). Thesc species 0024-4(174/87/010155 + 25 $03.0010 '" 1987 T he ullllfan Socic:I)' or London '56 J. 1-1 . J)IC:K SON EJ .rI.. gro\\' in a sevcrcl y ICSlill g hahitat which has cxcccdingly wcl l-draincd skclctal soils tllldcr lhe Slrong ul¡raviolcl radiatioll 01' a fi en cloudl css ski es, with low prccipita¡ ion and relali\'c humid it)'. The)' are subjcclcd 10 g rcal diurnal a!ld scasonal variatiOlls ortcmpcralurc (Fcrn adopullé, 1976; Ortuilo, 1980). Espcciall )' cole! Ic mperaturcs occur in Ihe lo\\' Iying arcas, Ihe caldera boltoms bctwcc n 2000 and 2200 In (Cañadas· Kaltscc, Voggenrciter, 1974). The absolutc mínimum rccorded by R. \o\'egncr in 1911 in Cañada de la Grieta (2078 m) is - ¡G.l oe. T he mean annual Icmpcraturc is goC and Ih e 30 year mean or prccipitatio ll a l halla (2300 m ) is 463 mm. Limilcd by thesc r:l clo rs, Ihe sparsc fl ora compriscs a largcly shrubby a nd masll y vcry opcn \"cgc la lion. Sparlof]lisus supraTlubius (L. ) Wcbb & Scn h. and Adrl/ owrjJ/ls uiscosus (\Villd .) \Vebb & Benh., IWO of lhe mOS I abundanl spedes, are 1cguminous shru bs. The former has bee n shown 10 ha ve N-fi xin g nodules (C. T . \Vheelc r, personal eommunicalion). It gi"cs ils Ilamc to lhe class Spa rlo0'lisdtu tlubigmi 01' Voggenrcilcr ( 1974), lhc mos l cX lcnsivc "cgclalion type wi lh up lo 25 species. Endemic annuals are absent, a lack characleris lic 0 1' Ihe whole Cal1 arian nora, ¡¡ lid hcrbs are few. OUlsland ing examples oflhe lalter are },:dÚUfII aubaimlllfll Webb & Bcrlh. OI nd Vio/a dlrimlllhijo!ia Hum b. & Bonpl. The ,'jo/a wilh onl )' one 0 1' two other species comprises lhe clo15s Vio/tita c/¡tiralll/¡ifo!ial' 01' Voggenreiler. A fe w springs and small streams are Ihe onl)' pennanclllI )' wet arc.u in Ihe Nalional Park. The)' SLLppOrl a vegelation in which Ihe large lussoc ks 0 1' Cart.\' calderat A Hans. and the tall M enllw 10llgifolia (L.) Huds. are conspi clI ous. Rocky 510pes locall y suPPOrt Echium wildjlftlii Pears. ex l-l ook fi l. , found also al high alt itudes in Ihe T aburiellle Nalional Park, La Palma ( ~'ia c h a do , 19 79b). It forms giganlic roselles of narrow leaves and finally 2 m or more high colu mns 01' thousa nds 01' red nowers. Carlc¡ uisl ( 1974) has drawn attention lo ils similarilY wilh Arg)'roxijJlt ill/1/ species 01' Hawaii; such lifefonns can be sce n as adapl alions 10 wilhsland Ihe rigours of high altilude Jife :11 low latitudes, Ihough no ecophysiological sludics ha"c bcen carricd OUI as rel on Ihe Canarian planls. Above 1800 m Pi,ms c(/}wrimsú C hr. Sm. ex OC has markedly Ihinlled out and 2000 m is about Ihe nalural alliluclinallimil 01' Ihe Ircc. In Ih e cad y 19505 Ihe " Palrimonio Portstal dtll:.sltldo" eSlablishcd several experimental Slands 01' Pi'lIIs species ancl other cOllifc rs wi lh lhe aim 01' a floreslalion in ami around Las Cañadas. Pimls radiala D. Don was selected firsl ¡lIId dllri ng 1954- 55 aooul I I ' ~ hce larcs were planled in Cañada Blanca and Cariada del Capricho. In 1956 CtdrllS allal/lica (End l. ) Carrierc, which lhrivcs, was pl anled al .. few localilics, and scallered Pilll/S rmltlriel/sis (approximalely 72 h) we re planted 011 Ihe easlcrn side 01' Ihe Cuajara Ucanca escarpmcnl; all Ihesc pines have now bccn removed bUI SOIllC Crdms allauli((l slill remain. The caldera and the lowcring peak 01' Teic1 e, reaching 37 18 m (12198 fi ) form the Nalional Park, eSlablished fi rsll y in 1954 wi lh an arca 01' 1I 685 ha ,lI1d re-eslablished in 1981 10 Ih e ex lenl 01' 13 571 ha (Fig. 1). They are no\\' rcad il y accessible by roacl and cable-car (opcralional sinec 1971 ). Aboul .. million visi lors eome caeh year to Ihe Nalional Park by ea r and bus, nrriving al aU scasons, exccpl when snow infrcquelltl y blocks passagc. Thcse numcrous \'chidcs and lourists come frorn Ihe low- rl ying arcas o f' T enerife ami Ol her Canary Islands where a lien planls abound as wccds, I'uderal s and gardcn planls. Propagulcs musI arrive frcquenlly bul inlrusive specics are, lo!' Ihe mOS I pal'l, , '" CANARY ISLAN:J. "2~::)¡I----..,jLT EIDE NATlONAL PARI( TENERIFE 0, __'~ '_--,<30 1- I I 'm Fi¡;(II'" l . ~ I " I ' uf T"II,',"¡!i' . 10,,,, ¡n!; ,hr 1<A' ~lioll "r (he T .. ¡tk N:uiuII ,,1 I':.rk. incollspicuuus. Howcvcr, invadeN; a re far from bcing a bsclH and I\VC nI )' ninc h:wc bccomc \Vel l cstablishcd . Onl)' a le\\' workcrs have rccordcd alien platllS ¡,:- rowing in Las Cañadas (0 11 T Cllcrilc a caiiada is a n allm'ial plain "" ithin lhe caldera). T hough 19th ccntur)' scicntists from H umboldt onwards ha \"c visi tcd Las Caliada .~ and c1 imbcd Pico de T cid c. SVCllIcnius ( 194-6 ) appcars 10 have hecn the fi rs t 10 attcmpl a comprchcllsivc lisling 01' Ihe fl ora. Firsll y, he disc lI sscd " Plants rcstrictcd lo Ihe Canar)' Islands" ami sccondly, Ulul er lhe hcading "Other spccics 11 01 cxdusivcly C;lIl arian, which lo rm pan of the fl ora of Las Cailadas'" he listcd 31 spccies. He did not spccif)' which of the la tl er he thought were a ntllropochorolls invaders. UlIch ( 181 9, 1825), /Jo/lrgeou, Ho lle ( 18G l ), Christ (1 885, 1888) al! ga"e some records which llave relevance In Ibis paper. Seemingly lInawarc of S\'ente nills' list, Lid ( 1967) rccordcd Ihe altitudíllal li mils 01' plallls, indllding man ), weeds, 0 11 T encrilc ;I ne! ol he !" Canar)' Isla nds which he visited sevell times betwec ll 1954 ami 1967 bul 111 0sll )' in Ihe 1960s. He, too, did 11 01 spec ify whic h plallls he IhOllght werc introducliolls in Las Cañadas. Lid's 1I 11merolls records mrt kc il clear Ihal many spccies elasscd as weeds h;¡\'e alti ludi nal limits a baul 1500 111 (4920 rt ) on Te l1l~ r ire ; this is Ihe li mil 01' cult iva lion al Vilaflor Oll the south slopc 01' the istand . \\'ilh o nl )' slighl refc..ence \O S"elltcnius ami Lid, I-I ansen ( 1970) d isc lI sscd bric fl y Ihe introduction fl ora of Las Cañadas. S"elllcnius galhned specimellS frOIll Las Cañadas unlil the 1960 s; Ih ese have been publ ishcd by Santos & Fcrnamlcz (19 77- 19B2). 111 a shon d iscussio l1 of Ihc flora 01' Las Cailadas, Kunkel ( 1980) gavc a sclectioll of mderal specics regardcd as illlroduced hy pasloralism. 158 J. H. OICKSOi\' 1:.7 .-tL. rcafToreslation ami lourism; Ihis is bascd almos! cntircly 0 11 the work of Svcntenius ( 1946).