Marked seasonality and high spatial variability of protist communities in shallow freshwater systems - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue The International Society of Microbiologial Ecology Journal Année : 2015

Marked seasonality and high spatial variability of protist communities in shallow freshwater systems

Résumé

Small eukaryotes have key roles in aquatic ecosystems, influencing their local environment, global biogeochemical cycles and climate. Their impact depends on community structure, which varies along time. However, very few studies take into account temporal variation. This is especially true for small, shallow freshwater systems, which remain largely understudied despite their wide variety, global surface and intense microbial activity. We have monthly followed changes in the community structure of small microbial eukaryotes (0.2-5 μm cell diameter) for 2 years in four ponds and one brook located in NorthWestern France based on massive 18S rDNA amplicon 454 pyrosequencing. We detected a total of 3742 stringently defined operational taxonomic units (OTUs) encompassing all recognized eukaryotic supergroups and lineages of uncertain affiliation. Although geographically close, protist communities in the five ecosystems were contrasting, with very few shared OTUs, suggesting that environmental selection mainly drives community structure. The temporal dynamics of different high-rank taxa appeared complex and rapid at monthly scales. Despite this, a clear and reproducible seasonality was observed. As expected, low-abundance OTUs dominated the community. Although some of them appeared sporadically or remained at low frequencies during the survey, others occasionally reached relatively high abundances, sometimes recurrently. This shows that at least a fraction of low-abundance eukaryotes constitutes a seed bank. The annual proportion of primary producers, free-living heterotrophs and parasites appeared remarkably constant among the different ecosystems, suggesting underlying trends of ecosystem carrying capacity for these functional groups.
Fichier principal
Vignette du fichier
ismej20156a.pdf (2.07 Mo) Télécharger le fichier
Origine : Publication financée par une institution

Dates et versions

hal-03022559 , version 1 (23-02-2024)

Identifiants

Citer

Marianne Simon, Purificación López-García, Philippe Deschamps, David Moreira, Gwendal Restoux, et al.. Marked seasonality and high spatial variability of protist communities in shallow freshwater systems. The International Society of Microbiologial Ecology Journal, 2015, 9 (9), pp.1941-1953. ⟨10.1038/ISMEJ.2015.6⟩. ⟨hal-03022559⟩
83 Consultations
1 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More