Structure and environmental drivers of phytoplanktonic resting stage assemblages in the Central Mediterranean Sea
Autor: | Francesca Andreoni, Samuela Capellacci, Silvia Casabianca, Michele Scardi, Tommaso Russo, Antonella Penna, Fabio Ricci |
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Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
0106 biological sciences
Mediterranean climate Ecology biology Settore BIO/07 010604 marine biology & hydrobiology fungi Dinoflagellate Aquatic Science biology.organism_classification 010603 evolutionary biology 01 natural sciences Algal bloom Ditylum brightwellii Diatom Mediterranean sea Abundance (ecology) Phytoplankton Resting stages · Assemblages · Structure · Sea surface temperature · Depth · Mediterranean Sea · Phytoplankton Ecology Evolution Behavior and Systematics |
Popis: | Phytoplankton species can produce resting stages that persist in the sediment over long periods and accomplish important ecological functions. With the aim of investigating the phytoplankton assemblage structure in relation to environmental drivers and human pressures, we analyzed resting stages of diatoms and dinoflagellates, including harmful algal bloom taxa, in the surface sediments of 3 Mediterranean regional areas. Abundance of resting stages was determined by molecular quantitative polymerase chain reaction assay. Multivariate data analysis confirmed that the abundance of resting-stage assemblages seemed related to depth. Regional differences in the composition of the resting-stage assemblages were evident and environmental drivers were correlated with those regional differences. Three main groups of samples were defined according to SST and depth thresholds. Samples from the northern and central Adriatic Sea (average SST < 18°C) formed the richest assemblages, both in terms of abundance and species richness, while deep samples from all other basins (depth > 368 m) were poorer and less diverse than those from shallower sites (depth ≤ 368 m). Resting-stage taxa contributed differently to the 3 groups. Diatom spores and dinoflagellate cysts were the most abundant taxa, but Alexandrium minutum cysts and Ditylum brightwellii spores also accounted for a large share of the overall inter-group compositional distance. The structure of resting-stage assemblages can be regarded as a time- and space-integrated response of a subset of phytoplankton species to environmental conditions, including the physical oceanographic dynamics that favor or prevent sedimentation of resting stages. |
Databáze: | OpenAIRE |
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