PRESERVATION OF CYCLOTELLA MENEGHINIANA KÜTZING (BACILLARIOPHYCEAE) ALONG A CONTINENTAL SALINITY GRADIENT: IMPLICATIONS FOR DIATOM-BASED PALEOENVIRONMENTAL RECONSTRUCTIONS

Authors

  • Gabriela S Hassan Instituto de Investigaciones Marinas y Costeras (IIMyC), CONICET-Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales, Juan B. Justo 2550, Mar del Plata, Argentina.
  • Claudio Germán De Francesco Instituto de Investigaciones Marinas y Costeras (IIMyC), CONICET-Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales, Juan B. Justo 2550, Mar del Plata, Argentina.

Keywords:

Taphonomy, Diatoms, Shallow Lakes, Community Paleoecology

Abstract

In order to elucidate the effect that physico-chemical lake characteristics exert on diatom valve preservation, the taphonomic signatures of the target taxon Cyclotella meneghiniana Kützing was assessed in twenty five shallow lakes of the Pampa plain of Argentina. Fragmentation and dissolution indices were quantitatively related to environmental variables by means of univariate and multivariate techniques (Generalized Linear Models, Redundancy Analysis and Canonical Correspondence Analysis). Valves showed signs of fragmentation and dissolution, and different stages of taphonomic damage were recognized. Dissolution significantly increased with salinity, pH, carbonate and bicarbonate concentrations. Environmental constraints on valve fragmentation were less clearly identified in the dataset. Besides its key role on valve preservation, salinity also accounted for a significant, although lower, percentage of the variation in diatom composition of death assemblages. These results encourage the use of diatom taphonomy as an indicator of past salinity fluctuations in Pampean shallow lakes. Taphonomic profiles can be used to reconstruct past environmental fluctuations, as well as to identify assemblages subjected to significant taphonomic biases. Combining diatom taphonomy and community paleoecology constitutes a promising tool for maximizing their respective strengths while downweighing their limitations.

Author Biography

Gabriela S Hassan, Instituto de Investigaciones Marinas y Costeras (IIMyC), CONICET-Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales, Juan B. Justo 2550, Mar del Plata, Argentina.

Soy Doctora en Ciencias Biológicas de la Universidad Nacional de Mar del Plata. En mi Tesis Doctoral, titulada "DIATOMEAS ESTUÁRICAS DEL SUDESTE BONAERENSE: DISTRIBUCIÓN, COMPOSICIÓN, DIVERSIDAD Y SU APLICACIÓN EN PALEOECOLOGÍA", estudié la distribución de diatomeas a lo largo de gradientes estuáricos actuales del sudeste bonaerense. Los datos fueron utilizados para construir un modelo estádistico (función de transferencia) que permitió reconstruir cuantitativamente valores de paleosalinidades durante el Holoceno. Actualmente me desempeño en el Centro de Geología de Costas y del Cuaternario como becaria Postdoctoral del CONICET, estudiando la distribución de diatomeas a lo largo de gradientes ambientales continentales del centro de Argentina a fin de desarrollar modelos de transferencia de variables relacionadas con el clima.

Published

2018-07-26

How to Cite

Hassan, G. S., & De Francesco, C. G. (2018). PRESERVATION OF CYCLOTELLA MENEGHINIANA KÜTZING (BACILLARIOPHYCEAE) ALONG A CONTINENTAL SALINITY GRADIENT: IMPLICATIONS FOR DIATOM-BASED PALEOENVIRONMENTAL RECONSTRUCTIONS. Ameghiniana, 55(3), 263–276. Retrieved from https://ameghiniana.org.ar/index.php/ameghiniana/article/view/3144

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Section

Articles