Page 1 - Calvo_e_al_1995

Ois rribu lio n, sl ru~lu re nnd J!henology or r osidonfa oceanic a mendows
al ong slcllian eoasu •

S. CALVO, C. FRADÀ ORESTANO and A. TOMASELLO

l.~tborarorla d/ E<:olotu: Mqrt11tiul • DìptJrtinfcnla d/ ki«wu BùtaJÙt:lrc
.setrUtà•vnito, v-.,~. J/1- 1 9018 PalennD

ABSlll.ACT' - DistrfbutiOll. nrvctUnl and phe~~olocy or Posldonlq ouanico
mcollowS alon& Sirllbn cmst.S m reponrcl. Posùlonla beds m rrcqucmly round
in Slclty, espn:Wiy alons tbc SOitliH:astcn~. nonh-"'<SW!lll\d "-aiUII CWS~l.
Laf ..,-..,. per sboOI is i<k&iGed u 1~ most imponw van.blc ~n lhe
plk:ftoqical p:u-:atnctcrs 1be rhizGmt:a ani\U2l mnn prirllllr)' producllon tumcd
out 10 be among tbc blgbest valucs o~cd In tlle Meditcrranenn Sca.
Flow.,rinJ and fntilins of PosiJ!onla ou011ico are frcqaeN ond can occur cvcry

)a<.

Kq ••tmlJ: PotldOirltJ «tllni(Q. Si<tly, OlstributlOcl. SltuC'Iure, Pbcnolc>_gy.
Prirnosy production.

INTROOUCTION

Stud~s earried 0111 b) MOUI\ER & PlCARO (1952. 1953a. 19S3b) on Frcru:h,

Algcrian and Sicilian Posidcnia octOJt!a; (Liruw:us) Oelile mcadows mMk lhe bc~:innlng
of 1bc modem approxh to lbe knowledgt of lhi$ lmpon;111t Mtdit.eiTlllll!an ccosystem. 1n
p:uticulac. owing ID obscrvatlOliS an alpi and ranaoo.,amlc communitics belonging ID

ortbc q..:le Ptnùlonftl a<taJJica mc.sows, MOUSIER &. PICARD (19Slb) confirmcd in

Sidl)' thc: re511lts obtalncd alon~; che French 5nd Algerillll Mtdhcrranean consts. '111csc

ornbscrvaiÌons represcnt a hclpful refcrentt to cvalu:ue the anlhropic nlu:ration degrec

the sublliUied benlltic communitk$ In lbe Wl fony decade&: m~~ttover. they provide
inf01111atioll on the dlstribution or lhe Posidonla ocunica mudO\\'$ In Sicily. Por
c>.ampk:. as regatds 1M Culf of Palermo. lhc ahallow Posldonltl ouOJtlca mcadows,
dest:ribcd half a ttnrury ago ncar Vergine Marin. hnvc disuppcllrcd, whìlc e~rly
composition and Slnlc-tUT\! ahttations of !be phytobenlhk communilies atone the eas~m
~- (Acqua dd Coc:sln) """" ,..,poncd al lbe bcginning o( l.bc Fiflies. tn !be following
decadcs, owing 10 lhe ,..,ncwal or studics on phytobenlhic ttommunitics In Sicily.
p;utic:ular l'osidonla outJJiica fom~ations (récifbarriùe) were rccordcd (SORTINO, t967),
and preliminary qu;,lit<~tive tnfomt~~tion on lhc reproducl.ive pltcnoloB)I of Porft!D11ftl

o.O«Dnica werc repoatd along lbe weS1an coa!.B of lhe lsland (CIACCONE&. SORTI.-:

1974). Al tbe bctinnlnJ of 1980 specific problcms coneeming thc: structure and
dynanùcs or 1he submcr:td nurine beds m Siclly wcre diSCII$Scd (for a revlcw. scc
l'RADA ORE.STANO &. CAI.VO. 1992; TOCCACELJ &. RIOOIO. 1989).

OlSlRJBtmON

Composhion aod slructurc of l.hc ~bstr.num condition lhc senlemcnl nnd tlte
devclopmcnt of PtJsidcnia ouanic.o along O~e. COQSIS of Sicil).

• Wod: supprott:d by a gtant fn>m lbe twim M.U.R.S.T. (60'ilol

GIOR.'iALE BOTANICO ITAUAI'(O ·VOLUME Il?, l, 199S