Vignette d'image

Mitchell, Edward

Nom
Mitchell, Edward
Affiliation principale
Site web
Fonction
Professeur ordinaire
Email
edward.mitchell@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/357
_
0000-0003-0358-506X

Résultat de la recherche

Filtres

2
2
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 2 sur 2
  • Publication
    Accès libre
    Testate Amoebae (Protista) Communities in Hylocomium splendens (Hedw.) B.S.G. (Bryophyta): Relationships with Altitude, and Moss Elemental Chemistry
    (2004)
    Mitchell, Edward 
    ;
    Bragazza, Luca
    ;
    Gerdol, Renato
    We studied the testate amoebae in the moss Hylocomium splendens along an altitudinal gradient from 1000 to 2200 m asl. in the south-eastern Alps of Italy in relation to micro- and macro-nutrient content of moss plants. Three mountainous areas were chosen, two of them characterised by calcareous bedrock, the third by siliceous bedrock. A total of 25 testate amoebae taxa were recorded, with a mean species richness of 9.3 per sampling plot. In a canonical correspondence analysis, 63.1% of the variation in the amoebae data was explained by moss tissue chemistry, namely by C, P, Ca, Mg, Al, Fe, and Na content and a binary site variable. We interpreted this result as an indirect effect of moss chemistry on testate amoebae through an influence on prey organisms. Although two species responded to altitude, there was no overall significant relationship between testate amoebae diversity or community structure and altitude, presumably because our sampling protocol aimed at minimizing the variability due to vegetation types and soil heterogeneity. This suggests that previous evidence of altitudinal or latitudinal effects on testate amoebae diversity may at least in part be due to a sampling bias, namely differences in soil type or moss species sampled.
  • Publication
    Accès libre
    Thécamoebiens muscicoles d'un mur d’enceinte du château de Neuchâtel – les protistes constituent-ils une partie négligeable de la biodiversité ou plutôt une « majorité silencieuse » ?
    Mitchell, Edward 
    ;
    Arnet, Thierry
    ;
    Chatelain, Auriel
    ;
    Derungs, Nicolas 
    ;
    Lara, Enrique 
    L’analyse de quelques échantillons de mousses poussant sur le mur d'enceinte du château de Neuchâtel a révélé la présence de 23 taxons de thécamoebiens : dont 10 Euglyphides et 13 Arcellinides sur un total de 117 espèces recensées au total, tous groupes taxonomiques confondus. Ce total de 23 taxons est sans doute une sous-estimation compte-tenu des découvertes récentes d’une diversité inconnue d’espèces et taxons de rangs supérieurs au sein des différents groupes de protistes, y compris chez les thécamoebiens. Ces résultats illustrent le potentiel de découverte d’une diversité méconnue dans le monde microbien, même dans des régions où la diversité des organismes vivants a été bien étudiée depuis des siècles., The analysis of a few moss samples collected on the walls of the castle of Neuchâtel has revealed the presence of 23 taxa of testate amoebae, among which 10 Euglyphids and 13 Arcellinids, out of an overall total of 117 observed taxa, for all taxonomic groups. As hitherto unknown species and higher taxa are continuously being discovered within the various groups of protists including testate amoebae, this total of 23 taxa is most likely an underestimation. These results illustrate the potential for discovery of a poorly known diversity within the microbial world, including in regions where the diversity of living organisms has been well studied for centuries.