INVESTIGADORES
PAN Jeronimo
capítulos de libros
Título:
Geological, Physical and Chemical Foundations
Autor/es:
PAN, JERÓNIMO; PRATOLONGO, PAULA D.; CUADRADO, DIANA G.
Libro:
Mudflat Ecology
Editorial:
Springer Nature
Referencias:
Lugar: Berlin; Año: 2018; p. 1 - 49
Resumen:
Modern tidal flats are coastal geomorphological features with a recent geologic history (Holocene period, 10,000 YBP) that are found globally, under different climatic, hydrodynamic and sedimentological regimes. They are primarily characterized by fine-grained sedimentary deposits (silt and clay) that present unique physical and chemical properties, in comparison to other sediment types. The input of sediments to mudflats can be either riverine, from offshore, and/or from the erosion of coastal sedimentary deposits. Tides and tidal currents are the dominant hydrodynamic forces shaping mudflats, with wave action playing a secondary role. The occurrence of intermittent or temporary flooding and the presence of variable redox (oxidation-reduction) conditions are typical features of mudflat sediments. The temporally and spatially variable changes from aerobic, oxidized states of mudflat sediment and porewater to anaerobic, reduced states drive particular redox reactions that govern the characteristic chemical processes and biogeochemical functioning that distinguish mudflats from other coastal settings. Mudflat sediments are not inert; the high surface area : volume ratio of fine-grained sediment particles offers a vast and structurally-complex landscape for colonization by microbes that rely on surface-adhesion processes. Photosynthetic microalgae belonging to several taxonomic groups (collectively known as microphytobenthos MBP) are the dominant microorganisms growing in association with sedimentary particles, and forming a biofilm layer on top. In addition to physical forces, living benthic communities modify sediment properties as part of their normal physiology (micro-and macro-biota) and feeding, movement, and burrowing activity (macrobiota), especially in relation to stabilization and destabilization processes. These may ultimately have marked effects on sediment stability and geomorphology. The interplay between such biological processes and sediments in mudflats is currently an active field of research.