Preprint volume - SIBM
Preprint volume - SIBM
Preprint volume - SIBM
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Pre-print Volume - Posters<br />
Topic 1: BIODIVERSITY AND CONSERVATION SCIENCE: CONTRIBUTING TO MANAGEMENT<br />
Chlorophyta 17,7%, Ochrophyta 20,8%), while 169 species were identified in the today<br />
samples (Rhodophyta 73,6%, Chlorophyta 15,5%, Ochrophyta 10,9%). As shown in Fig. 2,<br />
in both data set the taxon Rhodophyta is the richest in species, with an increase after 80<br />
years. On the contrary, Chlorophyta and mainly Ochrophyta decrease. In particular, number<br />
of Ochrophyta species is halved after 80 years.<br />
Fig. 2 - Floristic comparison between 1927-2008. Fig. 3 - Comparision of corographyc groups between 1927-2008.<br />
Confronto floristico tra il 1927 e 2008. Confronto dei gruppi corografici tra 1927 e 2008.<br />
Only 40 species are shared by both the data set, being 191 the species exclusively found by<br />
Funk and 129 those exclusively present in today samples. Among the shared species, 5 are<br />
endemic (Balliella cladoderma, Halymenia floresia, Nithophyllum flabellatum,<br />
Nithophyllum punctatum, Peyssonnelia squamaria). Other endemic species are exclusive of<br />
single data set (33 in the Funk’s one, 26 in the today one). The allochthonous species are<br />
totally different in the two data-set: 2 in Funk’s (Acanthophora nayadiformis, Hypnea<br />
spinella) and 3 in the today one (Acrothamnion preisii, Asparagopsis armata, Caulerpa<br />
racemosa). The comparison of corographyc spectra is shown in Fig. 3. On the overall, the<br />
dominant corological groups are the same in both data-set, with the dominance of<br />
Mediterranean species, that slightly decrease in time. In general, an increase of warm water<br />
species (Tropical Atlantic-Boreal, Tropical Indo-Atlantic and Indo-Atlantic) and a decrease<br />
of cold water species (Atlantic-boreal, Atlantic-Pacific, Circum-Boreal and Circum-<br />
Austral) were recorded.<br />
Conclusions – Several differences arise from the comparison of the two data-set, 80 years<br />
distant in time. Probably, the lower number of species found today is due to a lower number<br />
of investigated samples and sites and to different collecting techniques; on the other side,<br />
modern direct sampling procedures are more efficient than ancient indirect ones. However,<br />
the increase of anthropogenic impacts cannot be excluded, also on the basis of a drastic<br />
decrease of Ochrophyta species, mainly of the genus Cystoseira (Serio et al., 2006), and of<br />
an increase of Rhodophyta, due to an increase of water column turbidity. The influence on<br />
the algal associations of the recent and invasive colonization by the allochthonous species<br />
Caulerpa racemosa could also be taken into account for these changes, but must be better<br />
studied in the future. The analysis of chorographic spectra also seems to sustain the<br />
anthropogenic disturbance hypothesis, together with co-occurring changes in climatic<br />
conditions, enhancing the presence of warm water species. In conclusion, an evident<br />
decrease of biodiversity was recorded in the Gaiola Marine Protected Area after 80 years,<br />
with a rearrangement of species in the main chorographic group, due to both climatic and<br />
edaphic (anthropogenic) factors. The presence of a Marine Protected Area, by reducing the<br />
anthropogenic impact, may enhance local biodiversity in the future.<br />
References<br />
FUNK G. (1927) - Die Algenvegetation des Golfs von Neapel. Pubb. Staz. Zoologica di Napoli, 7 (Suppl.): 1-320.<br />
SERIO D., ALONGI G., CATRA M., CORMACI M., FURNARI G. (2006) - Change in the benthic algal flora of<br />
Linosa Island (Straits of Sicily, Mediterranean Sea). Botanica Marina, 48: 135-144.<br />
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010<br />
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