Proceedings of the Second Mediterranean Symposium on Marine

PROCEEDINGS OF THE SECOND MEDITERRANEAN SYMPOSIUM ON MARINE VEGETATION (ATHENS, 12-13 DECEMBER 2003)
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lamourouxii) GDOR (sub Bryopsis balbisiana)
Penicillus capitatus Lamarck At B
Pseudochlorodesmis furcellata (Zanardini) Børgesen v. furcellata Abt !
Rhizoclonium tortuosum (Dillwyn) Kützing SC GDOR
Ulva intestinalis Linnaeus C ! HbM R
Ulva laetevirens Areschoug C ! HbM GE (sub U. lactuca) T3 (sub U. lactuca)
Ulva linza Linnaeus C !
Valonia macrophysa Kützing P C
Valonia utricolaris (Roth) C. Agardh P ! HbM T
Fucus vesiculosus Linnaeus and F. spiralis Linnaeus, found in 1996 in Liguria (Albisola
M., SV), are not included: <strong>the</strong>y were probably discarded by human activity (recreational
fishing). It’s worth stressing that exactly in <strong>the</strong> same locality, F. vesiculosus was found,
apparently settled, by Piccone at <strong>the</strong> end <strong>of</strong> 19th century (1889; 1891).
The chorological spectrum <strong>of</strong> <strong>the</strong> actual list <strong>of</strong> Ligurian macrophytobenthos is showed in
Fig. 2A. The cosmopolitan and sub-cosmopolitan elements dominate (C+SC=30,3%),
with entities characterized by wide distribution (A+AP+IA+IP=23,0%). Elements with
warm affinities are more important (P+Abt+APt+At+IAt=19,3%) than <strong>the</strong> ones with cold
affinities (Ab+APtf+IAtf+CB+CBA=16,0%). The <strong>Mediterranean</strong> component (M)
accounts for <strong>the</strong> 11,2%.
Fig. 2: A) Actual Chorological spectrum. B) Historical Chorological spectrum.
Data in literature before 1950 enumerate 351 taxa. Of <strong>the</strong>se 208 have not been
recorded in <strong>the</strong> last 53 years, but 77 <strong>of</strong> <strong>the</strong>m are dubious. The chorological spectrum,
excluding dubious taxa, is showed in Figure 2B: elements with very large distribution
dominate (28,3% and 22,4%); elements with warm affinities are lower than <strong>the</strong> ones
with cold affinities (respectively 14,2% and 21,7%). The <strong>Mediterranean</strong> component is
13,4%. In Tab. 1 <strong>the</strong> trend <strong>of</strong> each divisio is showed.