Linking river sediment physical properties to biofilm biomass and activity

River sediments are composed by a variety of grain sizes which determine their permeability and biogeochemistry. The aim of this thesis was to test whether differences in river sediment physical characteristics generate differences in biofilm biomass and metabolic activity in a Mediterranean river....

Descripción completa

Detalles Bibliográficos
Autor: Ann, Vannak
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/302110
Acceso en línea:http://hdl.handle.net/10803/302110
Access Level:acceso abierto
Palabra clave:River sediments
Sediments fluvials
Sedimientos fluviales
Biomass
Biomassa
Biomasa
Biofilms
Enzymatic analysis
Anàlisi enzimàtica
Análisis enzimático
Rivers
Rius
Ríos
Mediterranean Region
Mediterrània (Regió)
Mediterránea (Región)
55
574
577
Descripción
Sumario:River sediments are composed by a variety of grain sizes which determine their permeability and biogeochemistry. The aim of this thesis was to test whether differences in river sediment physical characteristics generate differences in biofilm biomass and metabolic activity in a Mediterranean river. To this aim, formulae for estimating hydraulic conductivity were reviewed, and the relationship between sediment grain-size distribution and microbial biomass, and microbial metabolism depth gradients were analyzed. Results suggest selecting the Kozany-Carman formula to estimate hydraulic conductivity for Tordera sandy sediments. Sediment physical properties affected accumulation of organic matter, chlorophyll-a and bacteria but this effect was different depending on hydrological events and microbial group considered; bacteria being the most affected. Microbial activities in sediment depth were regulated by the permeability of streambeds through organic compounds contributing to microbial activities. Hydraulic conductivity is among the most important physical factors driving biogeochemical dynamics and microbial processes at Tordera river