Macrozoobenthos e decomposizione fogliare in ecosistemi fluviali sardi: prime considerazioni sul fiume Silis (Sardegna Settentrionale)

The purposes of this research were to examine and compare the breakdown rates of one specie (Ulmus minor) of tree leaves at three sites along Silis River (Northern Sardinia) and to follow macroinvertebrate leaf colonization, focusing our attention on the values of abundance, biomass and density of macrozoobenthos and its functional groups, based on feeding mechanism. About macroinvertebrate analysis, the organisms of shredder functional group showed the highest biomass for all the three sites examined, according to the fast decay coefficients. On the three sites studied macroinvertebrate communities proved themselves to become slightly different as a result of an increasing number of collectors from the upstream site 1 to the downstream site 3 according to the theory of the River Continuum Concept.