A comparative faunal analysis was carried out in sandy littoral localities differing both morphologically and in human impact. The study sites were located in the Western Mediterranean basin along the coasts of Morocco, Tunisia, the Maltese Islands and Italy. These were typical beach dune ecosystems more (Smir, Morocco, Zouara, Tunisia, Burano Italy) or less (Ir-Ramla tat-Torri, Malta and Ir-Ramla l-Hamra, Gozo) structurally developed accordingly. Species richness was evaluated using standard trapping techniques with pitfall traps along transects perpendicular to the shoreline. Only isopods and coleopterans were used in the analysis. In each locality, an analysis was conducted on both the beach and the dune separately and on the entire ecosystem in the two seasons (spring and autumn). Species were studied both quantitatively and qualitatively using ecological coefficients (relative abundance) and Fishers diversity index. To evaluate the evenness of the community Shannon-Weaver index was calculated and compared to Brillouin index. For both indices, the maximum values were computed and were used to obtain the evenness of the community through Pielou. In addition, Simpsons dominance index was considered. Percentages of similarities between localities were analysed in the two seasons and in total through the Renkonen index. The overall analysis showed that general trends could be found for both studied orders and gave indications on habitat quality. The study showed that, when monitoring was carried out systematically both in space and time, arthropods could be used as important tool to assess beach health.
Comparative diversity analysis in sandy littoral ecosystems of the Western Mediterranean
Chelazzi L
2003
Abstract
A comparative faunal analysis was carried out in sandy littoral localities differing both morphologically and in human impact. The study sites were located in the Western Mediterranean basin along the coasts of Morocco, Tunisia, the Maltese Islands and Italy. These were typical beach dune ecosystems more (Smir, Morocco, Zouara, Tunisia, Burano Italy) or less (Ir-Ramla tat-Torri, Malta and Ir-Ramla l-Hamra, Gozo) structurally developed accordingly. Species richness was evaluated using standard trapping techniques with pitfall traps along transects perpendicular to the shoreline. Only isopods and coleopterans were used in the analysis. In each locality, an analysis was conducted on both the beach and the dune separately and on the entire ecosystem in the two seasons (spring and autumn). Species were studied both quantitatively and qualitatively using ecological coefficients (relative abundance) and Fishers diversity index. To evaluate the evenness of the community Shannon-Weaver index was calculated and compared to Brillouin index. For both indices, the maximum values were computed and were used to obtain the evenness of the community through Pielou. In addition, Simpsons dominance index was considered. Percentages of similarities between localities were analysed in the two seasons and in total through the Renkonen index. The overall analysis showed that general trends could be found for both studied orders and gave indications on habitat quality. The study showed that, when monitoring was carried out systematically both in space and time, arthropods could be used as important tool to assess beach health.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
