Diatom-driven recolonization of microbial mat-dominated siliciclastic tidal flat sediments
Modern microbial mats and biofilms play a paramount role in sediment biostabilization. When sporadic storms affect tidal flats of Bahía Blanca Estuary, the underlying siliciclastic sediment is exposed by physical disruption of the mat, and in a few weeks’ lapse, a microbial community re-establishes....
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión enviada para evaluación y publicación |
| Fecha de publicación: | 2017 |
| País: | Argentina |
| Institución: | Comisión de Investigaciones Científicas de la Provincia de Buenos Aires |
| Repositorio: | CIC Digital (CICBA) |
| Idioma: | inglés |
| OAI Identifier: | oai:digital.cic.gba.gob.ar:11746/8170 |
| Acceso en línea: | https://digital.cic.gba.gob.ar/handle/11746/8170 |
| Access Level: | acceso abierto |
| Palabra clave: | Geología biological sediment colonization diatoms ecological succession filamentous cyanobacteria microbial mats microphytobenthos |
| Sumario: | Modern microbial mats and biofilms play a paramount role in sediment biostabilization. When sporadic storms affect tidal flats of Bahía Blanca Estuary, the underlying siliciclastic sediment is exposed by physical disruption of the mat, and in a few weeks’ lapse, a microbial community re-establishes. With the objective of studying colonization patterns and the ecological succession of microorganisms at the scale of these erosional structures, these were experimentally-made and their biological recolonization followed for 8 wk, with replication in winter and spring. Motile pennate diatoms led the initial colonization following two distinct patterns: a dominance by Cylindrotheca closterium in winter; and by naviculoid and nitzschioid diatoms in spring. During the first 7 d, cell numbers increased 2-17-fold. Cell densities further increased exhibiting sigmoidal community growth, reaching 2.9-8.9 × 106 cells cm-3 maxima around d-30; centric diatoms maintained low densities throughout. In the 56 d after removal of the original mat, filamentous cyanobacteria that dominates mature mats did not establish a significant biomass, leading to the rejection of the hypothesis that cyanobacteria would drive the colonization. The observed dominance of pennate diatoms is attributed to extrinsic factors determined by tidal flooding; and intrinsic ones, e.g. motility, nutrient affinity, and high growth rate. |
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