patterns of algal succession in a perturbated marine intertidal community

/ Phyol. H, 506-512 (1978)

P A ' n ERNS OF .AI.G.AI, SUCCESSION IN A PERIURBA l EMARINE IN IER I IDAL C O M M U N I I V

Stei'en ,V. .\Drpanmrnl «)f HioloKual Sticmc. Cîlifiirnu Stale University.

Fullerton. Caliloniia <rj(J34

and

Mark Af. LittlerDepartmcnl uf Ecology and iLvulutioiiary Biology, Univcnily of Caliromia,

Irvine. C:alir<>rnia 9*^717

ABSTRACT

Patterns of atgat surrewion for a srwage-pottutfd nndart unpidtuted habitat near Wihon Cm'e, San CtrmenteI\t/ind. Catifomia. wrrr Uu/tird from Drrrmhrr 197-f InJutir 1977. Resident poputatioru were anatyzed for 56fully denuded and 34 undL\turhed control qiuulrats during11 asse^smrnt penoits. I he denuded qtiadrat.\ in ttie per-turbated (pidiuted) hahttat showed renwery within l.t) moas determined try cm>rr. percent simitarity and species di-versity Comparisons with control plots. The short recox'er\times oj the utffut poputation.s domtuatinfr the perturlmteithabitat indicate that these species maintain relatively con-.\tant overatt atninittinres due to their potentiat for rapidrecruitment and grcnt'th. Denuded t{iuidraL\ in the unpot-luted hiitntnt did not shim' recovery ei'en ajter 30.0 mo.These tfuadraLs were dominated during the jirst 1.3 mo trfalgae characteristic of thr perturbated area, including fil-amentous Ectocarpareae, cotoniat diatoms and tduegreenatgae. PcUilonia fawia (.\tiitt.) Kuntzf (1.3-3.0 mo).and Scytotiphon lotncitiaria (I.yngh.) J. Ag. and Col-pomrnia sinuosa (Roth) Derb. (d Sot. (1.3-5.0 mo)uvre atmnitant .shnrtty fottirwing ptot deniulation and pro-vided thick grirwths thai may have excluded other algae.The simitanty between ttir species mcufrying the stentizedplots during the first few months and those that prrnnde themajority of ewer in the perturtnted area supports the hy-polhfsu that the dominant atgae of the upper and mid-intertidat regions of this hatntat consist targety of eartysucces.Monat or opportunistic species wtth high capacitiesfor growth and reproduction. Addttionatty, these experi-ments suggest that algal popiitation.s described for otherperturbated epiltthic systeiris also represent resilient subcti-max auociations.

Key index words: cotonization; disturbed enx'ironments;poltutton; riKky intertutat community; sewtige; succession

Although ruiiitcrruH ûuc^vsional Miidicit in nxkyinteiiiclal habitats have U-cn done, these have rarelygcneraietl quaniiiative data or tested hypothesesconcerned with the structuring of cotnintiiiitics. Ihrmanipulative approach, so successiully employed

'Arrrptfd I July I97H.* A(i<Jir«« lor rrprinl re<|ur«u.

for exatnple l)y Havion (I'171, l"»7.Sa. h. 1973). rep-resents ati exceptiotj where cotiuiiutiitics have IK'CIIstudied by [x-rforrning realistic peituibati<ins andtTiotiiioritig <)Ul)M'(|iK-nt succcssional evetits. Thesestudies have niostiv involved the removal or add'*tion of sjK'cies presutned to IK- fututiotialK iinpor-tatit atul have tiot iticluded succession ftoin fullyileniidcd surfaces.

Studies of pcrtttrbated cotntiiunities have ge-nerally concetiitated on lieUl descriptions of pop*''lation.f or lalxiratory atialyscs of physiologicalrespj)fises oi itidividual organisms, 'fhe latterapproach, although ptoviditig tmuh data ott llK*physiologiial etology of marine platits atid atiitiialsutider stress, has generally failed to yield predictiveinfortnatioti coticertiitig (K-rtutb,itiotis of natural|)opulatiotis l)ecause of the faihne to sitiiulate fielf'cotiditions or to understatid iiilly the functiotiu'roles of the <lominatit orgatiistns. Additiotially>many earlier studies of |K-rttnl>ated svstems haveiK-en of litnited value due to the miavailability ofdata describing the pre-itnpact cotiditioti or cot"-parable unpolluted systems suitable for controls-

The rcxky ititertidat near the Wilsoti Cove sewageoutfall on Sati Cletnente Island, California (Fig •)is ideally suited for sttidies of the role of etiviroti-metital perturbatioti in the structuritig oi algal c<m''mutiities. Both distutbed and tmdisttnlH-d habiuiishave In-eti des<rilH-d pteviousK (l.ittU-t and Murray197.')) and the envirotimetital ieatutes of the ((Utiallhave Ijeeti reported (Kenis et al. \\)12). We view thisstudy as an attetnpt to ex|K-rimetitally verify ititer-pretatiotis of cotmniuiity stiu(ttne ior the VVil'*""(k)ve outiall area derived Irotn extetisive published(Murray and Littler 1<»74, Littler atid Murrav l'.»7.'»)and unpublished standitig st<H k data. I hese iticludethe hy[)othesis that the dotninatit algae of the upl'*âti<l niid-intertid,il |M>rtiotis oi the sew.ige-ittipactedarea consist largely of earl) siuxessioiial or "op|X"^tutiistic" s|)ecies with high capacities f«)r growth atioreproduttioti. I heoretit allv, the abutnl.itues ofthese otganistns result in a sulKlitnax coniniutiitylor the tjpiwr shoreline tiear the otitiall which ischaracterized by a physically iluctuatitig etiviroti-

5(H»

AI.C..\L SICCESSION 507

"lent dtie to the variable discharge of nutrietit richbut spontdiialU toxic eiihtetit.

Briellv. the Wilsoti Cove eflluetit consists ptitnar-ily of ttntreate<l hutnati excret,i. i<M>d scraps iVom a"less hall, <lisiniectants, bleach and detergentswlii<h are releasetl at the rate of approxitiiatelv95,(){)() I/day otito a rcxkv shoreline l.li m alnnemean lower low water. Bleach atid di-tergetit con-ffntiatiotis ate tnitiitnal; however, pine oil disinfec-•atit isused abutul.ititlv (-ISL' I oi *»()'/r ciincenttate/y ) in the daily satiitatioti of lavatoties atul is ati iin-portatit btit sjKtiadic coni|Hitietit of the eiiluent.Ihe ayeiage dissolved O^ concentratioti of the sea)vater is ca. 5.5 tng/l at the |>oitit of discharge andincreases to 7.0-8.0 nig/l, a tati};e t\pical ior inipol-luted <He;ni surface watets, at a distatue M) tn ftom'ne outiall tertiiittus (Ketiis et al. 1972). Measure-"ii-tits of l)i«Hliemical oxvgeti detiiand wete «>(M0.')1'K <VI (tnean = 22.S), values tvpiial oi i;nv dinnes-'<c waste watets. Wilson Cove ellhtent is diluted sev-• ral hutidted to a tbous.uul limes withiti lU) rti of"he outiall teitnituts where «)xvgeti cotuenttatiotis3rc alxive levels advet se for sensitive tnarine «)t gan-jsms. (;oliiortn levels iti exiess oiCaliiortiia adtiiin-jsirative Co<le minimtttn standards (I.OOO/lOO tnl)'••r public water-tontatt areas are also restrii ted(Kenis et al. 1972) to withiti M) tn of the otitfall.Mtxitig maintains sewage p.ntides in su.spetision asevKli-im-,! b\ a lack of seditnetitatioti observed in-•fitidalU or Mibtidallx tiear the studv regi<in.

•"or the past itve vears we have satnpled the•%al-dotniti,iu'd rinkv intertid.il tii.u to-epibiot.i to"c-tertiiitie the seasoti,il patteitis oidistribuiion and•'btindatue of the biological com|H)nents oi the sew-''K«"-|»o||iiied and the nearbv uti|x>lluted cotnnuini-" " (Murrav and Littler 1974. Littler atul Murtav•" ' 5 ) . I he presetit contribution represetits an ex-• •"si oi this e.n lier wot k atul was desigtiecl t<» de-

: i) ii algal comtnunities thatacteristic oiliabitats show high resilietu v bv their ,ibilitv

to recover <|uicklv alter |XMtutb,itiotis. atul ii) wbeth^^ •« primatv eifect of etnirotimetital sttess is to fa-«)i- early successiotial alg,il populatiotis. A primary

"Elective was to test the h\ pothesis developed earlier"'••t the up|HM to mid inteitidal tegioti oi the dis-

"•H'd ,tiea. \>hi( h teptesents a Ihu ttiatitig envitoti-'( •"t (litettU ex|X)>etii|x>tietits of

"Mhatged sewage (e.g., pitie oil disinfectant), is" " o i d b J" "o

g g pitieiinated by suJx limax algal fortns.

our (oi)ii);tiin

ANt) Mif:TMOt>S

|»ctin;iiicnt » l.'» m'111 ir«t.iii((lr ttrrc r«t.il>li«hril

a» a (Hi1974 on

, >i „ , |.|,"» riiilwdiird into the *iil«ti,)ir .mil the foiitenls pholo-

'' ' * " ' ' * ' " ' l " "" ' " ' * ' ••" "' ''"• ••|>ilHoi,t»»,«» inaniiallv rriiiove<l*>HI h l ' | iHi , t»,«» inaniiallv r r i i i e l. 'nc iiM k \iitt.i(r« ihoioiighU Mia|N-(l with wire hrushe* an<l

'^fi Suib(e> m i e then l«ittie<l lor up to 10 h with ixutahle"' '""'"• ' • M'""'K<'» »»«kc<l m 7(l'» e<h.iiiiil *«rir ustsi to

l>Mr.iir aiut iiiieiiMfy ihe burning, l-ollowing thi» sier-

KIC;. I. t.iH.ilion ot the San Clenieiuc IMand ((.alifoinia)»tucl\ sites.

iti^ation priHr<tuir. pt.Hs wcic phoiograpticHt uiih iiiira-rnt litmuhidi tixcals lixiiig pl.iiii iiutrtMl Us tcnoidinn chloniphvll llu-o l c M n e ; ihesc pholographs levratrtt alt pkrt« il the iiiahiltt\ to <|tialitaliveU detetiex|irMiiiental Miitaio trom Miiioiinctitig n.iiuial (oniniunilin(i.e.. coinplele icti>\er\ ha<l apparently <K(urre<i).

Oinconiitaiit viiih ihc e\|N-rimental MiitK. (|uantitative anaK-xvk or the (tiMrilHiiion ami alnimtame ot algal ManctitiK M<M k» Jorihe oiillall aiul un|»olhiir«1 areas were [Kriorn>e<i. Ihese datasulMtaiiliaird tmt r.Mlirr re^joit (tJliler and Miirrax I975J thaiseasonal and aiiiiu.tl changes in the Uilv.n tUive htologKal cciin-intinilies aic- tew Iliiwever. since one ol the ex|>eiiniental giiaUwas III .lelerininr v»hcn the su.iessional pl.Ms lur Urth arras hadcome into e<|uilil>tium hiih their surn.undmg natuial connnu-nilK-s. foiii loniiol plots uric sel«ir<l loi eath aiea Irom amongihe slan.ling simk samples IM.Ms weie chostn on ihe liasis oltheir visual ami <|uaiiiiialise similarii\ to the algal communitit-t<Ncup\ingitirex|irrimenlalsuita<espri<ir lodearame I his prt>-ceiluie plesenlcNl the adxanl.ige that lor e.ich aiea. comparisonswere maile wilh ihe hioia ot iiii()istiir(>r<l plirts ihal had ex|K-ri-eiued enMiontiieiit.il (i>ii<liiionerimeiiial. 8 tontroi) were ana-U/e<l in the sewage-peitutl>ale<l area and 70 (44 e\(>eriineiual.i.*t» iiintioll in ihe undisiurlied halMtal during ihe siud> Data arepiesented as |>erieiit cover and calculatetl lor e.uh s|)eiK-s as amean ot ihe toiii n-pluaied s.imp|<-> uken cluiing each moi r-ing |>eii<«l. ex.epi m the uMiltol plots ol the undisiurlied haliilalkheie oti Iwo otiasions onlv iliice samples were assevsetl.

Ihe phoiogiaphitneirK melhinl <les«iil>e<l pieviousix (Ijttlerand \ lnita\ l lCi) lor slandmg sliHk assessments ol ma(ri>-ep<-hiota was useit t)imtiK each visit, photographs (color and inlra-recl) and detailed helil notes v»eie taken lor each cjuadrat tcigen-eraie ihe nutiieiical dala emploxed in the anal\ses.

I hree melh.wls were emploxed lo measure c hanges in disTrsity(Mtlerns; simple counts ot taxa were us<tl to indicate rkhnru.with the Shannon (Shannon and Weaver I<H'.>) imlex (H',) andISelou s (t9«i'.») evenness index (,r,.| utiti/ect lo const run diversiiv(Mlterns eniphast/ing the apportionment ol cover among ihetaxa I he Brav and Curtis (P.J.'w) index was emploxed to measureihe degree ot ircoverx ('? snnilaiiix) ol experimental vtmples bxrom{uriMins with ihe unalteretl iiiiiinJ pktis.

508 N, Ml RRAY AM) .MARK M. 1,1 I I 1 KR

-f, 2, Ihvrrsily of ihr firrturholrtt arm tmsrit upon rm-rr(%): imlursjilt (imtritt ifxuutrats art uvnaf^n jor It.l) amt •t.O mo a.v\nsmfnt.s.

K> 14

MONTHSFici, 2, Simitario (9t) brlwrrn c-xfx-rimrntal and control |

frir prrturbaicil (pollutrd) ( • - • ) and un|)<illiitrd (A-A)Itascd upon alxal «ovcr: mean (x) imiUriiv • SI) for controlpUiii Iriim prrturhairti aie-a aic tM»rd U|x>n loinpariMin* lic-twrrn Drtrrnhrr 1974 and April 1975 (n - 4); those (or unjxil-luic«l area tontrot* arc from progriruivr (:om(NiriM>n» for Decem-ber 1974 ihrouKhJune l»7H(n - 0),

RFSl'LTS

III iM>th ihc pcrtiirbaicci (polluted) aiul tinpolkit-e<l ({uadraLt lateral CDcroachnicnl by altaihcd algaewas insigtiiruant atul all KTruitmciit ap|K-arf<l toresult lr«)m »ti<>|x-iuic(l frpnKliiciivc rrlls or v • t•-lative fraKtncnt». Additiotially. lx>ih study areaswere cKcupif<l almost ftitin-ly by nuutoalâc: otilvrarely dicJ matroitivcrtcbratcs (otiiributc ituMsur-able rover (see Littler and Muriav l*.)7.')). Hetice,because of ibeir low abutidatice atid .sporadic <Kcur-rence in samples, inacroinveriebrates have Ixreti ex-cluded frotn our atialyses.

Prrtuthfitrd arm. I be Merili/e<l plot* in ibe outfallarea sbowed rapiver excee<led lOO.O';? prior to theSterilization of plots iti tbe sewage-itnpactcd /otieand consisted of small, tiirf-fotttiiiig orgatiistns;dominant forttis were bhicgreeti algae. Vtva cnlifor-nica and PseudottthiHltrmn ntgra. Witbiti 1.0 tno aftersterilization, overall cover bad readied 100.1% ( I a -ble I) an«l cover values for bluegteeti algae (49.9'j?vs. 45.0*>J) and V. catifoniira (42.7% vs. 44.9%) werereav)nably similar to tbose determined for tbe iden-tical plots prior to tbe experimental treatmetit. P.

1 Aai,r I, Cm-rr iif atgur Jnr (hr prrlurtMilrit tpottutnt) arra: \<atuntrprrwnl mean nifft Jin 4 rrptuate II. lim' quaittals jnr fMnmts jot.touing pt»l Hmtutnttim: i<aJur% jiir (ontrnt <pmdrati are ai-eragn jot 0.0and 4 0 mn awewmenh.

T M * P * I J SO

BlucKrn-n atâeVti'a inttfomuaPsruitiUtlhiKtrrmii nigrnCfrtutium fntuttuml^ttiitarpacrar/coloiiial diatom*Petalimia jatnaOverall biolic covrr

62,221,215.915,00,H

115 I

49,942.73 0

4,5

KKU

47,052,9

4,00,4

21,30,1

125,7

53.03H,88,20,1O.I

100,2

Nn.J'.

|0,81,33,0

qua<trati465

Control quadrats U)

O.W.1.170.92

1.00

0,fi90,6.50,57

O.(J2

ttigra atid (•rlulium pu.\ilhim, two sprdes cliatacter-istic of the ex|HM imetital area, sliowi-d slower recov-ery wbeti (oiiip.ticd wiib (otiltols, alibougli willii"3.(1 tno Ixitli .ipproa(he<l ahundaiKes detet tiiincdfor tbe experitnental (juadrals prior lo denudation.Fpiphytic growths of filattietitous K( tcxarpateae atulcolotiial diatotns grew s|)oradi(ally in tbe otttfall ateaduritiK tbe study atid reai he<l tiiaximutn cover(21.3%) iti late January (l.:i tno).

Witbiti ibe pertutbaied area, sitiiilatity (%) cotn-patisotis lu-tweeti (be ex|KM iinent.il atid lotittol plot*also iiidicaled fxlieiiiely rapid iccovety ol tbe alg*''loinnnituty. Sitnilarity (Biay atul (aiitis 1957) be-tween tbe two sets of ploi.s was cah tilaicd al i\\).f>'âfter O.K mo, a value similar to tbat est,ililishc'(i(7H.()%) for itibeietit variability attiong ibe controlteplitates (see Fig. 2). Sitiiilaritv decreased sligbdyafter 1.3 mo (r)1.0%) <lue to a blcKnii of filametitousKci<Harpaceae. but returtic-*! to 76.7%. by tbe thirdttiotitb.

Rapi<l recovery of tbe outfall biota was also indi-cated by cotntntitiitv parametets. A lot,il of five tax<iweie present in tbe ex|H-iitnetital plots prior to ster-ili/ation ( I able 2) and tbese wete tbeotilv organi'>"'*sattipled from tbe tontrol plots dtititig tbe study-Witbin l.O mo, four of tbese ba<l ap|H-ate«l oti tliccleared stjbsttale; otilv one otlier spec ies was presetitat tbe oiiuhision of the ex|KMimetit. Diversitv a*ttieasuied In H' , was 1.00 lor ibeexpetiitienlal pl<''"*Ix'foie tlearatue and average<l 1.00 for tbe controlplots. A value of ().9<) was reacbed for tbe expc*ri-tnetital c|uadtats by 0,K tno after denud,itioti. .A ^'" l 'ilar 11 etui (Hcurted for tbe evetitiess measuii" J r(Iable 2). Assessments perfortned after 1.3 "'"sbowed sligbllv bigber W^ diversitv for tbe de-nuded <|U,idiats <lue to itu te.ised K( t<Karp,ue.ie ••lu'colotiial diatom cover.

Vufmllutfd (ttrn. Kx|XMimetilal plots for tbe I'tJ-polluted area did not attaiti tbe tbaracterislic lay-ered cotnttiutiity as|M'(t (i,e,, cover exceeding lOC* 'sc-e Littler and Muiiav I97.'i) utitil tbe tbird tiiotit"of tbe study (Iable 3). Samples were <lotniiiated loftbe first 3 tno by algae strut tut.ill> ic-sembling tlof tbe outfall aie.i, ituhidittg filametitous Kcpaceae. colotiial diatotns atid bluegreeti algae ( I i3). wiib Petalottuija.scut (1.3-3,0 tno). atid i.olpominuoM and Scytosiphon lommtari/i (1.3-5.0 tiu)) I"*''iditig tbe majority of algal cover, (irowlbs ol ' •

and S. tomeutitria were accompaiiietl l>y '"'vi

AI,t;Al. SI CCESSION 509

T A B U 3. I'allrrtu of ilnttopmrnt of nlgar foloniung rUarnl pints in unpoUutnl area: values rrprnml mran tovrr (%l far 4 rrtliraUûailralt imliaird tn Dfffmhrr 1974.

liHitKt altrr clr«rancr

OR IS

31.5 37.816.3 <0.l2,90,5

23.522,5

5.11.6

so

<0.l

0,69,29,4

82,31,00.9

4 0

12.4

10.80,2

11,643,8

8,56.4

So

1,00.1

20.4

43,831,26 1

no2.00 1O.I

6 0

1.33.8

51,3

12,81,66.7

25.54.30.1

0.1

5.61.2

0.4

0.2

< o '

10.0

3,0

85.0

0,1

1.5106.0

0,0.

0.

0.0,4 ()t).l

7.50,0,

0.0.0.0.0.

110

O.IO.I

84,00,11,0

7.0.54,0

1,51.0O.I

8.0O.I

10.0012.0

19,0

0,11.03,00,10 1

ISO

O.I3,90.1

3.5.1

1,5

23,239,512,60,1

<0.l

4,01,2

17.5O.I2.8

15.30.1

<0.1<0.l

0.88.9

<(). I

0.20 1n

<0.l

24.0

2.74 1

12.8

2.3

2.05,8

16,9

3,9

1,4

.•M) 8

3.2

0.88,70.30.63.98 6

4.5

1.60.81.1

0.1

M.O

1.3

10.2

1.450.025.7

5.6

12,8

4H.94.5

43.29 10.3

3.316.40 1

11.8

'-0.6

<0.13.82.2

2.30.5

Ecuxarpaccac/colonial itiatomsalgae

rmn ntgrn Itollrtib.

frtnlonm jasda (Mull.) Kunl/c(•olpomfma UMMOWI (Roih) Dcili. & Sol.^ntoMphon tiimrntana (l.tiigb.) J. Ag,'''i« lalifoiimu Willc^•K>rgM mniiir\ii (I utn.) Arcnh ,

I ftiiitiliiuliilii llarv.Inmorfthtt Imum (\tiiU.) Kill/.»/«</>« iitftilliurii (('>nu-l.) Bom \- I hur.

I riiliiiimnum (Fail ) I>c I iini andC itmrola S. Sc C.y c i > r a i u l u i ( C i i r

'•iirnlliiia offiiimi/is var, ihiUn.w (i>r«,) Kutt.Ilhoihrix a\firfgillum Gray

h «pp.

um njftnf ( l larv . ) KU,riiMs ^(•lut(l

nitiilliiiiira (\<ilt) ('•atilnci(Coll.) S, & G.

(°>ai(liirrfifa Kvl.

cm ipfiiiiMis I'osi. X.- Riipr,''l<roiif,hiiniii tirwhiiiilm (Moiil.) Kalk.^ agtitdhiaiium |. Ag.'•"amiiim «pp.

Wvnnc{Kxitt.) Marv.(Maclh) l.cJ»L

l F l Kpril. W tlN»r>/(i S &• C.

hrutltyi »a» hrnilryi Giirdn,u,, ngmm Okain.

/Tdt ilmmltilum (("., Ag,) Mom.r..u//m Harv.

( / M p.

l'>Ulalg.iI .over 51.2 90,6 103,5 93.7 115,8 115,1 2O8.4 192.4 169.2 137.0 254.

a)vcr ol (lit- ci i is ioso Raljsia sp. ul i ich txr-HJ.O';; (il ilu- primary Mil)Mnitf VI m o al icrij,)ii. l{,ilf\iti sp, . as ic|><)iif<l h f i c . prohahly

'*'I>U-Mius tlif alici iialc lilc-hiMory phase tor /'. fas-'" iind S. lomrnlaria from southern (âliiornia

"VyiiiK- I «»(•)«>).Suhsc(|iiciit to the firsl tnonlh. (Viw ralifoniira

P'<>vi(|,.,| ;,| |t.;,sj 1,0% cover and reathe<l maxinuiin(L'li.'J'?) l.^ m o alter the initiation ol the

t. I'lots in the un|>olliite(l area were col-juvenile Njxiiiiplutes ol hiprfâ mnnirsii( lut ing the tliird month (NIaitli) and

m e w into larê e longate tlialli which by themonth provided ati extetisive overstorv rati-

lOU.O'O, Cover of /.\ mnivrsii was r e d i u e d hvf l h h monil) (l)e«emlK-r) to '>»,<»'* d u e t() mor-

Ill ol individuals atid lituttiated dttriiiK the last•" iiio ol tin- ex|H"riineiit, C.nmtlinii ofjfirina/is var.'*«"»i.vM, a turt-lormitiK articiilatetl coralline tlomi-

nant in the area ( ral)Ie 4). <lid not ap|>ear in s.implesuntil t>,() mo alter i learance; its tover i iureasetltliroii^h tl>e first 24 .0 mo and reat IKM! a mavi inumol 50.8',? (1 ahle S). Filamentous thalli o t C.euiimumrnlotiitinum, C siuintla atid the foliose. R/i4Miogtmsumof fill f. were abundant Vl mo rollowing tlearaiue huttheir cover lituttiated dtlritl^ the remainder ol thestuds, Sinfirissum fifianihunium, (iif^nrtitia aitialirutalaaiul I'tnofladio cnpiUtura ^rew alnin<tatitlv (Table 4)as coralline turl epiphxtes ami as s.i\irolous thallioti the tin|>olhite«l region ol tlie shoreline atut weredominant com|)onents ol the e\})eiimental s;implcsthere prior to sterilization. Uttle rccover>' of thesespeties was appatetit alter IL'.O mo; however, after!^0.0 mo. co\er ol C». anuiliiulain iiu teased to 1*5.79f.as <li«l S. aganUnanum (11.8**) and /'. capUlarm

Similarity com|iarisons (Bray ami Ctinis 1957)Ix'tween the ex|K'ritnentaI atici control plots for the

510 STEVEN N. MURRAY AND MARK M. I.I IPLER

TABU. 4. Mean algal caver (%) far rmtrol f>tob of unpnttulrd atra.

{%)

H.V. 5. DifrtMty nf uiipi>ttulfit arrti Invent upon cm>er ('/():Jar Ihr rontrot quattrals art avrragry Jot (1.0 Ihruugh 30.0 momenu.

Cigarlina tanaluulalACiirattina njfinnatu \ar. rhitrtuu

(rVt ) Kul7.Plrrmtailta (upittarra ((>rnrl.) Born. & I hur.SaTga.v\um agariUitanum J. Ag.Halulry\ itioua (iarcln.Egrrgui mrnitfui ( rurn.) AfCMh.(.nratlina t>antnuvmfn\t% Yrn<toLtthiiphyttum fmihiiMutnim (KIMI.) KIMI.Ciftutium puipurii\ten\ (*.ir(lTi.iMurrmm panftra K\l.HyHriiUlhon Hrnpirru (Fod.) AdryLuhnlhnx mprrgiUum Cray(irtuhum loutlm Hjrv.lirtulium fnuiltum (.Slaikh.) Lrjol.Bl lCriipommta ununvt (Roth) Drrb. & Sol.t<H4))ti>glin\um uffinr (Harv.) Kyi.(.mpiiiplrura roralUnara (N'oll) (iardll.(.rramium rajitttuittum ( f j t l . ) l>c I «>rii

4iul (. uniiiitn S. J! ' (f.Gtgnritna tpinoui (Kul/.) Harv.Haliptytim grtuiJf (l.aitH>ur.) Jnharu.Phfttmfkulix Inrrev VV'als.Ptrruwphimm lUnilrutdra (Mom.) Kalk.(•/«« latifiirnuii VVillrAniuMtotifltii piuififa K\l.

otbi/fniann «titnp. duhoUtma| h

Ceramium «|>pCtadiiphnra »pp.Cmhum fragUf (Sur.) Har.CyUmlrinaTpu.i rugittut Okam.Dtttyata ftahfttala (CU>II.) .S. & (;.F.uenia artxirnt .ArcvhGtutTMtitnium fnutlm (Marv.) Kyi.Jania Imrtla (Kuu) Grun.Laurrnim sinuota %. Ik (>.Laurmrm ipfilnMi\ Pcnl tc Riipr.Stfnhutgta ati>irrummna (J, Ag ) Kyi.Pr>tM>nnrUa<rar/Mililriibran<lia<raePieuttotithnrtrrma nigra Mollriib.RhuHymmut rati/trmtra var. califomua Kyi.SiknymrnuM paiifira (Kyi.) Kyi.Ttf/anirila %nfdfrae (Farl.) Abb.

45.4me ft

3o.U19.5lfi.9l(i.314^76.13.62.41.70.80.80.60.6

0.50.5

MimllM

Exprrimcnlal <ju.i<lral»0.81.33.04.05.06.0

10.012.015.024.030(1

Control (|ua(fratit (t)

Nau u

4 t67 (7

1016202132 '.25 :23 :

18

H'.

1.871.30).74I..5J

54L70.06.64

J.20J 30f.35

.83

J'.

0.630.730.380.79().H7O.til0.3(i0,5.1O.ti30.710.75

O.(>4

0.50.4

O.IO.I0.10.1O.tO.I

un|>(>lhitc-(l h.ibiiat revcalfd a pallcrn of i i grecovery durin>; ihe study (Fig. 2). Similarity of thesterilized plots t«) tlte cotitroi c{uadrats itu reased al-most litiearly Ironi values «i .O'i during the lirst (i.Omo of the experiment to 46.5% by 30.0 nio. Sea.%oiialsimilarity compariM)n$ ofthe control plots alone av>erased 08.4'^ during the stutly inditating that evenafter 30.0 mo. the Merih/e<l ex|>erimi-iital <|uadtatNhad failed to fully recover.

In comparitig the exi>erimental quadrats withthose of the coiitroU afier 1 yr. it fx'canie appareniihat greater <j»ver of crustose {Katjsia sp.) and earlysucccssional algae (Utva catifornica, Ceramium eatoni-anum, C. sinicola, Cladophora spp.) were prevalent inthe former whereas articulated coralline algae (Cor-atttna officitialis var. chitensts, C. i-ancouveriensis) an<lfoliose red algae (Gigartina canaluutata. I'teroitaduiraptllacea) were generally more abundant in the lat-

ler (Table 4). After 30.0 mo an increase in the coverof ihc scawtTds ihal lvpic;illy dnrniiutlc this rrgionof the shoreline—I'., of/irtnati.s var. ctiiteti\i\. (•. can-aticutata. P. capittacea, Sar^msum agardhtanum—oC'curre<l prixluiiiig (loser siniil.itity (4().*>9f) betweetithe unpolluted cxiKMiMiental and crititrol plots (Ta-bles ;?. 4; Fig. 2).

SjK'cies diversity also itureased during the study-A total of four laxa were satnpled iti the uti|)olhttedarea 0.8 mo after initiation of the experiments witha progressive iturease to VJ taxa alter l.'j.O tiio ( la-ble .')). .Slight declities iti the numlK-r of taxa weretioted 'J4.0 mo ('J.')) and :t().O tno ('J.'i) followitig ster-ili/ation. On the other hand, tlie tiearbv cotitroiplots averaged 18 tax.i for the studv. Diversity, asmeasure<l by II',. generally iiureasetl witb time(from 0.87 afler ca. 1.0 mo. to a maxitnutn of '2.35thirtv mo after plot dearame) and readied paritywith the average value (I.8.S) lor the cotittol plot*after otilv (i.O mo. The excepti«>tis to this tretui "^increasing divetsity (Table ^^) cHCttrted ditring ll""cover tnaxitna tif Scytosiphon tomentaria (.S.O mo) ;ttidEgregia menziesii (10.0 nio) and icllectcd tbe largefK-rcetitageof space fHcupied by these species. Kven-ness showed a similar depression (Table 5) at 3.0mo and 10.0 mo atid ratiged from a tiiaximum of0.79 to a minimum of O.liCi.

tJtSCtJSStON

Bluegreeti algae, filametitotts F,ct(Karpaceae atulloloni.il diatoms, all oi whit h h,ive pteviotislv beetite|H)tted to comtiioiiK (HCUI in a(|u.iti( eiivitoH'meiits under sewage stress (Borowit/ka 1972, Ci<>-liibic 1970, .\lunda 1974. Murrav and Littler 1974,Littler atul Mtirray 1975), were abund.itit cotiip""neiits of tbe eaiiv sntcessional sta^es for l)otb thesewage-|K'rturbate(l atul undisttubed ate.is (TablesI, 3), Uliui californica, which provided cotisidetabic<over in the sewage-affee te<f tegion <if Wilson (.ove.was also ati abutidatii com|)otietit of eatl\ stages of(i>loni/,itiori in the otitfall area. However, despilCthe fact that U. catijornua was among the earliest

,\l.(.Al. SI C.CE.SSION 511

org;uii,sins to appear on ihc inovcahlo nxks em-ployed ill a preliininarv expeiimeiii (I.iiiler andMurray 1973) lor the ideniiial out lall and undis-turbed areas, abundant growths did not tKiiir onihc unpolluted suuessional surfaces until 15 mo al-ter tlearatue. This was nol cx|X"tted iti view of theprelitninarv ex|H-riment atid otu extensive field oh-H-rvatitJtis ol tuiturallv disturln-d suhstrata oti theunpolluted shotelitie wheie alnuidatit p.ttches of U.catijdniicii rte(|uentlv tould IH" lound. We hypotli-csi/e th.it the iailute ol (/. californico to ptovideRreater lover (hiring the litsi lew inotiths ol theoxpfiiineiit, tnay liave Ix-eti due iti part to its exilu-sioti hy the ihitk. extensive growths of Scytusiphoiilonirnliniti, /'rfalonid /«.\rw and C.nlpomrriitt .siiiuo.'ia.t-Vt'rt spp.. alonK with ilie doseU telated F.utnomor-P'Ki spp.. liave connnonly been reportetl lo beatuoiig the lirsi colotii/eis of cleared nnkv inlerlidalsurfaces (f,g,, tiokc-nbain and Stipbcnsoii I'.>."i8.Norilurall \\)\H. Kahe\ 1'.).'): . F.tncisoti and /edler1978). Our lesuhs loi blucj^rc-fii algac. KctcK'arpa-leac and colonial diaiottis .stip|M)tt the hvpothesisInat the piedoininant algal constituents ofthe upiu-rshoreline in the sewage-impacted area are earl\SUccession.il orgatiisins also encountered on rec entl\<l>sturlK'd substrata in neaibv un|>olluted WilsonCove and other Southern (iaiifot nia intertidal com-"uiniiic-s (Wilson I'.)'J.">, Kinerson and Zedlc-r l'.»7.SVnirther, the previously di.scussed litetature as well••s «)ur own lield observations on utistable sectionsf)' the titipolluted Wilson ('ove shoieline and pte-I'niinarv exjHMiments for the same hal)itat (LittlerSlid Murrav H(7.')) makes tetiable a similar position•or U. coli/ornica. ilespite the failure of the presentPXjHMiment to fullv sup|X)rt this viewpoitii.

I he outfall stu(l\ |)lots showed rapi<l recoverv fol-lowing the expetimental distutbance. Because allcxjx'riinental surfaces were thorougliK sterilised«»iid had little or no encroachment Irom establishedsurrounding organisms, the (|uic k tc-coverv of blue-Rreen algae, Uhfi califoruun, (iflntiiiin pu\illum, I'sru-'i»lithmiernm nigrn, Kctcnarpaceae and colonial dia-•otns must have resulted from vegetative, sexual or«>H*xual repKKhtction mediated through susperuled• flls. These alg.ie c le.irl\ h.ive the c.ipaciu lor rapid•"I'cruitinent even under the inlluetue of sewage ef-'luent. I he short recoverv times shown h\ the algae^otnin.iting the distutbed shoreline sup|X)rt our<'arlier inter|)iet.ition of standing st<x k <lata (Littler•"i<l Murra\ I".t7. )) that patches ol thc-se spc-cies aj)-Pcar u> sliow considerable mortality due to exposure'o Sewage toxicants, \et tn.iititaiti rel.itivelv cotist.intPf>pul.itioiis due to their potenti.il for rapid iccriiit-'iic'iii. Further, we suggc-st that the abundances ofbltu green algae (Colubic I'.»7(). Mtinda I«>7-1). dia-totns (C.olubic 1«I7(), Uorowii/ka 1972). lilamentousEcicxarp.iceae (Munda I'.)7I). and l'h-<i and Hiitrr-"^'orpha ((.ottoti 1911. lUurows 1971. Borowil/ka'972. Munda 1974) in other sewage-impacted epi-''thic systems prolKibly represent resilient SUIK lim.ix

asscKiatiotis characleri/ed bv the {x>tential for rapidlecoverv after jx-riodic stressful disturbances.

l h e algal c(»miiuinitic-s that develojx*d on the cx-jx-rimental plots in the un[M>llutcti area had nol ful-ly rcHovereci after ."JO.O mo. 1 his was to Ix* expectedIx-cause recovery umes for mature rcxky intertidalcommtmities ate tvpicallv greater than 2 vr (e.g..(iuiler 19.')!, Daxton 1971). l h e commonly rejx>rt-ed ttetuls (Oduiii 19(i9) of increasing diversity andspati.il heterogeneity with time were also apparentlor the unix)lluted area successional plots, althoughdiversitv patterns c|uicklv re.iched paritv with, andexceeded those ofthe utialteted controls. 1 his trendwas slightly nuKlified at 3.0 mo b\ ihe abundanigrowths of large thalli of Scytosiphon lomnitarui thatcHCtttted in all of the ut)|X)lltite(l-atea (juadiats. .S\lomfutarm ,in<l its tvpical ass<Kiatc Prtatomafascia col-otii/ed experitnetJial suhsiraics iti (jtiantilics vastivgreater than their abundanrcs in siirnHin<iiiig un-(listutlHMl conitntitiitics. Cotiipatahio linditijjs wereie|)oite<l b\ Wilson (1923) who destrilx-«l colonialdiatotn.s. Ecti>ratptt.s, Scytosiphoti and Eiuiarnchur (asEuilfriuhiif but probabK I'ftalimia jasda) as domi-nant com|H)nents ol his pte-kelp .successional groupwhich coloni/ed submerged wcnxlen blinks as wellas cleared intertidal i<xk surfaces at l.;i Jolla, ( .ali-foinia. Also. Emerson and Zedler (1978) re[x»rtedS. lomrntaria duritig all seascnis and Colpimrmn siii-uiiui, l\ct(tftirpu.\ fHin-ns and Cernmtum rntonuniumduring certain seasons lo be favored by disturbanceiti their recoloni/atioti studies |x*rformed near S;uiDiego, California. During the pti-sent stuciv, theabundant gtowths of .S, lomnitano. P. fnscm and C.siituosa grew cjuicklx and presumablv to reproduc-live maturiiy. theti disap{XMred leaving a commti-nitv comprised of low-growing algiil crusts in addi-tion to juvetiile th.tlli of lotiger-lived algal forms.

Juvenile liprf^a mruiirsii s|xiroplivtes recruitedand dominated the utipolluted-atca successionalplots dut ing the spring and earlv summer and latgeth.illi which provi«leil consider.ible oveistory wereevidetit by fall (10.0 mo alter denudatioti) of thelirst year. I hese lindings suggest last growih similarlo re|X)tts bv Northctaft (I1M8), Widdowson (1972)and Bl.ick (1974) where extremelv rapid inonthlvgrowth rates of /•;. mnitirsii, e.g.. 78 ctn iti letigthper axis (Widdowson 1972). were tcHorded duringthe spritig atid summer, ^c)utlg E. mriizirsii sporo-phvtes also were frecjuentiv observed to coloniienaiurallv disiurlx*d substrata atnong surroundingcommunities at \Vilsc)n O n e . Ihesc observationscc>mbined with our successional results indicate thaialthotigh E. mnnifsii is genetall\ thought to be astructuialU-complex dominant of m.iture interiidalalgal cotnmunities (Littler and Murrav 1975), voutigs|X)rophvtes are able lo retruit effeclivelv duringthe e.irlv stages of commiinitv clevc-lopmcMit.

lt» cotKlusion, our results sttp|X)it the theoreticalsuccessional iiKMlel develojx-d by Connell (1975).1 his nuxlel predicts that patches vacated within rel-

512 STEVEN N. MURRAY' AND .MARK M. 1,1 11 l.KR

aiively niauire bioiic commiiiiiitfs will IK- most rap-idly coloni/cfi hy .species wiih long repriMluctive sea-sons which prcnlucc tiumcrous njotilc spores orlar\'ae. We exteiifl lhe characierisiics of this pi<»tieerspecies group, refcrrrcl to by Coniu-ll (I<»72, 197.'))as "opporiutii.siic" lo include alg;il forms wilh rapidgrowth rales, high priMluctiviiy and simple thallus-lorms wilh large surface to weight ratios (Ijiiler and.Murray 1974). Additionally, previous successionalresearch (e.g.. Wilson 1923, Bokenham and Sle-phenson I93H. Norihcraft I1H8. Fahey 1953, Ka-tada ami Saiomi 1975) in lhe rocky interlidal /onehas resuliecl in the cbssifkaiion of groups of earlycoloni/ers with altiibules similar lo those piesenled.Further, Ooiuicll (1975) adds tfiat patterns of com-munity development piedictively proceed along dif-ferent routes under Ix'tiigti ami stressful etiviron-inenis. with the latter conlitiually U-itig colotii/edand vacated by op|M>rtunistic s|M-cics. The sewage-impacted Wilson Cove shoreline has In-en charac-terized (Littler and .Murray 1975) as a harshenvironment due to the fiuiluating iiijuits «>! SJK>-radically toxic sewage; in contrast, lhe unp<illuledarea represent.s an environment thai is considerablymore fx-nign. Ihc rapitl recovery rates (Fig. 2) ofthe outfall algal dominants on denuded substratesand iheir charat teri/ation as early »uccessionalforms maiiitaine<l f)y stress as sulxlimax asstxiationsstrongly suggests a predictable pallet n for harsh en-virontnents. In the un|>olluted area, more complexpatterns of development were evident with greatercommutiity complexity Ixring achieved with tinjc.This predictable tremi for the less harsh etiviroti-ment was marked by large scale variations in thec-«>ver of certain temfX)rally domitiatii sjiecies (e.g.,Sc\to.Mf>hon tomrntarm, Efêf^ mruzir\n, Ratfua sp.)with a trend towarcLs increa.se4l abundatice of struc-turallv-complex algae wilh apparently tnore (otn-plex life histories atid seasonal!)-optimi/ed retruil-tnent strategies. We ititerpret these pallerns asindicative of ittcrease*! biological interactiotis and tobxr characteristic of community developmetit utiderintertnediate and betiigti physical cotiditions.

We *rr »rr\ ({fjirful to |jc k Vt I'.iiuhrr anil Keilh F. Ainol<l(f»clil jiiil UNiidttirv tup|Miri); M.iun(r I.. Mill, Aiidrrw V.. Km-dig and Palrkk Y. O'Brirn (Mrrili/jiion nf pltii*); ICirrn K. Y<>-Uiihara and Peng* J. IralHtr (held «up|M>M): I>ianc S, Uiiirr(illu!Mrati<>n<t). Wr would tike to atknoMlcdKC \M\ I j ru in iindO>mm.iii<l(r VVillijtn Kjt\ <>f the U.S. \ 4v \ fi>t ihrir i<Hi[NT;itioiiami .i«ti«i.iii<r »i(h I<>KI%IH« mi San Clcmrnic Nbncl. t hi* rc-^•iiiih ¥,»\ «up[M>rirfl in pjrl hv ihr (Hhir oJ Water Rew.it(hand trihiuii<>f(\. l'St)t. uixler lhe .\ll>iiiiieiil F'ii>Kt.irn nl Puhlicl.aw HH-37'». a< amended, aiul h\ the lni>erMi> nl Calilornia.Waier Reumrcrt Onier. a% (»arl of Water ReM-atih and leth-

l Prfi|e«i No. A-HM-tlAl, and Wairr Rrwnirte* OnicrW4<<t

Boniwit/ka. M. A. 1972. Ititertid.il algal »jx'<iellutioti. .-IMI/. y. \Uir. Ftrshuxil. tin. l.'.S:73-Kt.

Bray. J. R. & Curtis. J. I . i'.l.'i7. An ordination ol thr iipl.indforest (imitnunities ol Miuthern Wivonsin. AVn/. \liiiiiif;T.7

B U k . R. 1974. .Viine tNoloiptal inirrarlion* alletling iniertidalpopulalion* of lhe kelp t.prgta tamifmla. .\tar. BnU. '2H\H'.t-

*.m.Bokrnharn. \ . A. If. gc Slephriiwiri. I . A I'l.'W Ihr iiiliiiii/.|.

liiin of <leniHled rotk »utta<e^ in the interiidat region ol thec:apr PrninsuU. Ann. Solid \tiu. »:47-»l.

Burrow*. E. M. 1971. AsMrsinient oliMilhition ellcttt b\ the useol .ilg.ic. /V<»r. H. SM. t.nnitim Srr. H 177:i.'9.'>-.1()(">.

(Uiniifll. j . I I . I97'J. (jiiiitnunitv interactions on marine riickyititrttidal nhorci. Ann Hn\ t.n^. VyW i.W}-<i'i.

^^— I'.I7.'>. Some mcc hanisms priMliicirig structure in naturalcommunities: a IIUMU-I atul e\icl<-ncr Itotii field ex|)rriments.In (Jodv, M. I.. Sc Dt.imoiul, |. M. [Kd^l tuntofiy nrut I-A'iitulionnf (.ommuiiilifK. Ihc Itc-lkti.ip l'ic-\s ol Harvard UnivemiiyPress. Cattihridgc. NLiss-uhim-lts. 4(>()-lMI.

CcMlon. A. I). l'.)| I On the- growth of t'titi ttiltwima in excessivec|imMtit\, with \|H-ci.il tetcieiue to the I'tivi tuiisaiue in Bel-fast i.ough. ti"\iit (.imimiwiiin im .Snmgr t>i\f»iuit, 7th Ke|><*tl.I I (.Ap|x-ndix tV). l.<>ii(loii: I I M S O , l'JI-'t:>.

I)a\lon, I*. K. 1**71. (;oiti|H-tition, ilistiiilMiiie. ,nul ciMnniutiti>orgatiiâtiott: the provision atxl sul)s<'i|tietil utili/atiott olspare in a rwky intenidal cniminunity. /iro/. Monngr. 41:351-89.

— — ^ m73a. Iwocau-scif ic-snutir p.iititiniHiiK in .m iiiic-rtid.il(onnnunity: niaknig the right piediction loi the wrong tea-vHi. Am. .Vfl/, |07:«>tiL'-7(t.

I'.iTMt. Disîersion. clis|>er%;il. aiul prrsisieiice ol the an-nual intrrtidal alga. t'mlrtMti p<itmar/ormu Ruprrchl. flfotofHI54:4.'i.1-«.

I'.H^. Kx|H-iiiiirMi.il c-v.ilu.itioii ol ecological iloiiiiiiaiitein a r«Kky itttefti«l.il algal lottitnunttt. /.V«/. .I/OIIKIT. 4.5:137-.'.9.

Kniervm. S. E. Sc Zedler, J, B. 1978. Re(-olonizalion of interlidalalgar: an experimetital stitilv. Mar tiiot. 44:3l5-:24.

Fahev. K. M. I'.I.M. Ihe re|Mipulation of intertidal uanseris.Khmiora 5.'): 102-8.

(joluhic, S. 197(1. F.ffert of orgatiic pollution on hrnlhic com-niuniiies. Mm. t'oltul. tiutt. \\:t\'-<~l.

(iuiler. V. R. \\i'r{. I he recoloni/atioti c»f rrxk nurfacri and theprohirm of succession, t'np t'tix. K. .SOr. tasmiiuM 88:49-<><>-

Katada. M. &• Satomi, M. I97.*i. F.colog\ of algae, tn lokicla. J-A- Ilirose. II. IF.ds.| Aiti-aner o/ I'hyaitogy in Jiifxin, VFB Cm-tav Fischer Verlag |ena. 211-39.

Kents. P. R.. Salauir. M. H. *: Iritvhler. J. A. 1972. Enviroti-tnental study of lhe sewage outfall area of San ClementrIsland, trrhnuat t'n/trn \mvit I'nitnva tirsranh tirx'ftKp'ni'ntCrnlrr. .San Diego 292:1-.%.

Littler. M. M * Murray. S. N. 1974. Ihe pritnary pr.Kluctivityof marine niacrophytei ficim a rcxky intrrtidal umitnuttiiy-Mar.BuJ. 27:131-.V

1975. Itn(>act of M-wage on the distrihution. ahundaticratid community Mructure ol iiHkv ititettidal macro-otgati-isms. Mar. HuJ. .10:277-91.

Munda. I. 1974. Change* and auccession in the lieiithic algalasMK iation* of slightly |Hilluted halHtatx. HfV. Inl. Ofranngr-Mfft. .34;37-.V.».

Milita>. S N *: Ijttler. M M. 1974. Biological featuies of iti-tertidal coinmunities near the U..S. Nav\ sewage outfall. W>l*win <^(ve. San (.leniente Island, ('aliloinia. tnhnirat t'aprniVaiw/ Unttrrvn Crnlrr. S,lti l>i«-go .3!Hi:l-8.1.

Ncirthcraft. R. I). I'MH. Marine algal ciiloni/ation on lhe Men*teie> Peninsula. Calilor Ilia. Am.J. tint. 3.'»:3'.M">-4<»4.

()dum, F. P. I9«>9. I hr strategy ol rtinyMrin dcvclopmrnl. Sfi-rn,f I(i4:2ti2-7O.

Pieloii, F, C. l<Hi9. An tnlrnHuflwn In Malhrmalvnt Knitiigy. WilryIntervieiice. New York. 2H(i pp.

Shannon. C. F * Weaver. W I'.M't thr Malhrmaliiat thriin nfCommuntniliim. I niveisit> ot llhnois Ptess. t'llMiia. 117 PP'

WiddoWMin. I . B. 1972. (iiowth late tn t.girpn as a measureof |MillutioM Prm. Inl. Srawrnt S\mf> 7:2<iM-72

W'llvHi. (). I . 192.1. Some ex|>erimenlal oinervationti of marlnralgal successions, t.rotngy 6:303-11.

M |. I M>9. l.ile hisiou and ostematic stiitltes of soinCPatilu North Anieruan l'h.ieopli>ceae (brown algae). I'""''Catt/ I'utft. Hm. .10:1-88.

patterns of algal succession in a perturbated marine intertidal community

Documents