Phylogenetic and functional diversity of Eumycetes in pelagic ecosystems
type: Dataset
description: Microorganisms play major roles in aquatic ecosystems, primarily as the main actors for organic matter mineralization and recycling. “True” fungi (i.e. Eumycota) are among heterotrophic microorganisms that are highly efficient in recycling organic materials in natural ecosystems. However, the overall diversity of fungi and their quantitative and functional importance remain largely unknown in typical pelagic ecosystems. Environmental 18S rDNA surveys have recently highlighted the importance of microscopic fungi in the diversity of picoeukaryotes (size < 5 μm) in lake ecosystems, including particularly the members of chytridiomycetes (i.e. chytrids) as the dominant phyla. These studies and the known major roles of fungi in natural ecosystems such as soils have leaded us to venture the hypothesis that fungal diversity and functional roles are important structuring factors in pelagic ecosystems. The main aims of the thesis were to examine the overall diversity, genetic structure and quantitative importance of various phyla belonging to the Kingdom Fungi in freshwater pelagic ecosystems. Methodological tools were also developed for ecological investigations of fungal populations of interest. Phylogenetic diversity and quantitative importance of fungi (size classe: 0.6 and 150 μm) were analysed in three contrasting pelagic lakes. Environmental 18S and ITS rDNA surveys were performed during spring 2007 in the oligomesotrophic Lake Pavin, the eutrophic Lake Aydat, and the mesotrophic and humic Lake Vassivière, all located in the French Massif Central. Phylogenetic affiliation of sequences confirmed the presence and the substantial diversity of chytridiomycetes, known as parasites of primarily phytoplankton. We also have unveiled a sizeable number of sequences belonging to the fungal lineages of ascomycetes and basidiomycetes, mainly known as saprophytes. The seasonal dynamics of fungal community structure (essayed by TRFLP),and the quantitative importance of various taxono…
identifier: NNT: 2010CLF22090
issued: 2026-05-15T14:13:39.521708
language: fr
modified: 2026-05-15T14:13:39.521715
contact point: Organization
  fn: CCSD
keyword: diversite-microbienne
keyword: eumycetes
keyword: infoeu-reposemanticsdoctoralthesis
keyword: microbial-diversity
keyword: pelagic-food-web
keyword: reseau-trophique-pelagique
keyword: sdvsalife-sciences-q-bioagricultural-sciences
keyword: theses
landing page: https://theses.hal.science/tel-00769938

Phylogenetic and functional diversity of Eumycetes in pelagic ecosystems
type: Distribution
format: HTML
issued: 2026-05-15T14:13:39.549645
modified: 2026-05-15T14:13:39.504714
access URL: https://theses.hal.science/tel-00769938

test_moissonnage_selune
type: Agent