Meiofauna communities, nematode diversity and C degradation rates in seagrass (Posidonia oceanica L.) and unvegetated sediments invaded by the algae Caulerpa cylindracea (Sonder).
We investigated meiofauna and sedimentary C cycling in seagrass (Posidonia oceanica) and unvegetated sediments invaded and not invaded by the non-indigenous tropical algae Caulerpa cylindracea. In both habitats, invaded sediments were characterized by higher organic matter contents. No effect was observed for prokaryotes and C degradation rates. In seagrass sediments, C turnover in invaded beds was about half that in not invaded ones. Meiofaunal communities varied significantly among invaded and not invaded grounds only in bare sediments. In both habitats, nematode species richness and assemblage composition were not affected by the algae. The effect of C. cylindracea on the turnover and nestedness components of the Jaccard dissimilarity varied between the two habitats. We show that the presence of C. cylindracea gives rise to variable consequences on meiofauna biodiversity and C cycling in different habitats. We conclude that further studies across different habitats and ecological components are needed to ultimately understand and predict the consequences of C. cylindracea invasion in shallow Mediterranean ecosystems.
Department of Life and Environmental Sciences, University of Cagliari, Via Fiorelli 1, 09126 Cagliari, Italy. Electronic address: apusceddu@unica.it.
Antonio
A
Pusceddu
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, V.le Gallipoli, 49, 73100 Lecce, Italy.
Simona
S
Fraschetti
Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Via Rio Vivo, 86039 Termoli, Italy.
Mariaspina
M
Scopa
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, V.le Gallipoli, 49, 73100 Lecce, Italy.
Lucia
L
Rizzo
Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; Stazione Zoologica Anton Dohrn, Villa Comunale I, 80121 Napoli, Italy.
Roberto
R
Danovaro
D035961:Alismatales / Q000502:physiology*; D000818:Animals; D044822:Biodiversity; D002244:Carbon / Q000378:metabolism; D057486:Carbon Cycle; D046068:Caulerpa / Q000254:growth & development*; D017753:Ecosystem; D004784:Environmental Monitoring; D019015:Geologic Sediments; D058865:Introduced Species; D009348:Nematoda / Q000254:growth & development*
D002244:Carbon
Caulerpa cylindracea; Marine biodiversity; Meiofauna; Nematodes; Non-indigenous invasive species; Seagrass