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Effect of simulated climate change on the structure and functioning of Sphagnum peatlands-an experimental and modeling study
Auteur(s)
Editeur(s)
Maison d'édition
Neuchâtel : Université de Neuchâtel, Faculté des sciences
Date de parution
2016
Nombre de page
150 p.
Résumé
The main objective of this thesis was to investigate the response of Sphagnum dominated peatland to water table manipulations in an integrative approach. We conceived a mesocosms experiment that simulates artificial peatlands at different water regimes.
We first show that our mesocosms behave according to the literature, with respiration and decomposition rates enhanced by the combined effects of water and temperature. We hypothesize that this C cycle dynamic is regulated by microbial activity. To address this question, we investigate the topological change of micro eukaryotic interaction network along the gradient and show that the structure of the network evolves along the gradient, showing a change point around -10 cm.
Then we study the functional response of one functional group of micro eukaryotes, the testate amoebae. We show that environmental filtering constrained by manipulated water level promotes traits selection, and that this traits response can be used to mathematically model Hutchinson niche concept. Finally, we demonstrated the phenotypic plasticity on Hyalosphenia papilio, showing that traits selection acts both between species by community replacement, and within species by phenotypic plasticity.
We propose a framework to model environmental filtering, integrating all components of this study.
We first show that our mesocosms behave according to the literature, with respiration and decomposition rates enhanced by the combined effects of water and temperature. We hypothesize that this C cycle dynamic is regulated by microbial activity. To address this question, we investigate the topological change of micro eukaryotic interaction network along the gradient and show that the structure of the network evolves along the gradient, showing a change point around -10 cm.
Then we study the functional response of one functional group of micro eukaryotes, the testate amoebae. We show that environmental filtering constrained by manipulated water level promotes traits selection, and that this traits response can be used to mathematically model Hutchinson niche concept. Finally, we demonstrated the phenotypic plasticity on Hyalosphenia papilio, showing that traits selection acts both between species by community replacement, and within species by phenotypic plasticity.
We propose a framework to model environmental filtering, integrating all components of this study.
Notes
Defended on June 9, 2016
Jury :
Pr. Edward MITCHELL - University of Neuchâtel
Dr. Richard PAYNE - University of York
Dr. Vincent JASSEY - EPFL, Lausanne
Dr. Enrique LARA - University of Neuchâtel
Dr. Colomban DE VARGAS - Station biologique de Roscoff, UMPC
Pr. Daniel GILBERT - Univ. Franche–Comté, Besançon
Jury :
Pr. Edward MITCHELL - University of Neuchâtel
Dr. Richard PAYNE - University of York
Dr. Vincent JASSEY - EPFL, Lausanne
Dr. Enrique LARA - University of Neuchâtel
Dr. Colomban DE VARGAS - Station biologique de Roscoff, UMPC
Pr. Daniel GILBERT - Univ. Franche–Comté, Besançon
Identifiants
Type de publication
doctoral thesis
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