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Environmental factors affecting the balance of autotrophs versus heterotrophs in the microbial food web of temporary ponds

The relative abundance of autotrophic (A) and heterotrophic (H) organisms in the microbial food web of temporary ponds and its relationship to environmental variables were analysed. Four localities (43 temporary ponds) were selected for study. They were located in unaltered, protected basins without intensive agriculture or strong human pressure. Because the supply of allochthonous organic matter is expected to be higher than inorganic nutrient inputs in temporary ponds, we hypothesized that the microbial food web in these unaltered basins was dominated by heterotrophic organisms. Our results showed that the log A:H biomass ratio (A/H) was always negative, indicating strong dominance by heterotrophic organisms in these ponds. Moreover, A/H was negatively related to DOC concentrations, but this relationship was weaker in the locality with the highest DOC concentration. No significant relationships were found between A/H and the other environmental variables analysed, namely inorganic nutrients, fulvic acids, chlorophyll-a concentrations, macrophyte biomass or total zooplankton biomass. However, when the different groups of zooplankton were considered separately, A/H correlated negatively with cladoreran biomass and positively with harpacticoid biomass. Thus, temporary ponds differ from deeper ecosystems, in which the greater importance of autochthonous energy inputs leads to microbial food web that is more dominated by autotrophs

The financial support was provided by ‘‘Ministerio de Ciencia e Innovacio´n’’ (CGL2011-23907) and the Generalitat de Catalunya (Ref. 2014 SGR 484).

© Hydrobiologia, 2016, vol. 782, núm. 1, p. 127-143

Springer Verlag

Author: Àvila Izquierdo, Núria
López-Flores, Rocio
Boix Masafret, Dani
Gascón Garcia, Stéphanie
Quintana Pou, Xavier
Date: 2016
Abstract: The relative abundance of autotrophic (A) and heterotrophic (H) organisms in the microbial food web of temporary ponds and its relationship to environmental variables were analysed. Four localities (43 temporary ponds) were selected for study. They were located in unaltered, protected basins without intensive agriculture or strong human pressure. Because the supply of allochthonous organic matter is expected to be higher than inorganic nutrient inputs in temporary ponds, we hypothesized that the microbial food web in these unaltered basins was dominated by heterotrophic organisms. Our results showed that the log A:H biomass ratio (A/H) was always negative, indicating strong dominance by heterotrophic organisms in these ponds. Moreover, A/H was negatively related to DOC concentrations, but this relationship was weaker in the locality with the highest DOC concentration. No significant relationships were found between A/H and the other environmental variables analysed, namely inorganic nutrients, fulvic acids, chlorophyll-a concentrations, macrophyte biomass or total zooplankton biomass. However, when the different groups of zooplankton were considered separately, A/H correlated negatively with cladoreran biomass and positively with harpacticoid biomass. Thus, temporary ponds differ from deeper ecosystems, in which the greater importance of autochthonous energy inputs leads to microbial food web that is more dominated by autotrophs
The financial support was provided by ‘‘Ministerio de Ciencia e Innovacio´n’’ (CGL2011-23907) and the Generalitat de Catalunya (Ref. 2014 SGR 484).
Format: application/pdf
ISSN: 0018-8158 (versió paper)
1573-5117 (versió electrònica)
Document access: http://hdl.handle.net/10256/13682
Language: eng
Publisher: Springer Verlag
Collection: MICINN/PN 2012-2015/CGL2011-23907
Reproducció digital del document publicat a: http://dx.doi.org/10.1007/s10750-016-2897-1
Articles publicats (D-CCAA)
Is part of: © Hydrobiologia, 2016, vol. 782, núm. 1, p. 127-143
Rights: Tots els drets reservats
Subject: Metabolisme microbià
Microbial metabolism
Fitoplàncton
Phytoplankton
Llacs
Lakes
Title: Environmental factors affecting the balance of autotrophs versus heterotrophs in the microbial food web of temporary ponds
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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