Dynamics of soil processes under extreme meteorological boundary conditions [Elektronische Ressource] : response of below-ground carbon, sulfur, and iron cycling in fen soils ; effects of experimental drought and subsequent rewetting on internal carbon, sulfur, iron, and arsenic turnover in a soil from a northern temperate fen / vorgelegt von Klaus-Holger Knorr

Klaus-Holger Knorr

Sujets

• Biologie

Informations

• Publié par: universitat_bayreuth
• Publié le: 01 janvier 2009
• Nombre de lectures: 34
• Langue: Deutsch
• Poids de l'ouvrage: 7 Mo

Extrait

Dynamics of soil processes under extreme meteorological
boundary conditions
–
Response of below-ground carbon, sulfur, and iron cycling in
fen soils






Dissertation zur Erlangung des Grades Doktor der Naturwissenschaften (Dr. rer. nat.)
an der Fakultät Biologie / Chemie / Geowissenschaften der Universität Bayreuth















Vorgelegt von
Klaus-Holger Knorr
Geb. am 05. Februar 1978 in Schorndorf (Württ.)


Die vorliegende Dissertation wurde im Zeitraum von April
2005 bis August 2008 unter der Betreuung von PD Dr.
Christian Blodau an der Limnologischen
Forschungsstation des Lehrstuhls für Hydrologie (Prof.
Dr. Stefan Peiffer) der Universität Bayreuth angefertigt.

Die Arbeiten im Rahmen dieser Dissertation wurden durch
die Deutsche Forschungsgemeinschaft (DFG) gefördert im
Rahmen des Projektes Bl 563/7-2, einem Teilprojekt
innerhalb der DFG Forschergruppe FOR 562.




Vollständiger Abdruck der von der Fakultät für
Chemie/Biologie/Geowissenschaften der Universität
Bayreuth genehmigten Dissertation zur Erlangung des
Grades eines Doktors der Naturwissenschaften (Dr.
rer. nat.).




Tag der Einreichung: 29.09.2008

Tag des wissenschaftlichen
Kolloquiums 08.12.2008



Prüfungsausschuss:

PD Dr. Karsten Kalbitz (Vorsitz)
PD. Dr. Christian Blodau (erster Gutachter)
Prof. Dr. Egbert Matzner (zweiter Gutachter)
Prof. Dr. Gerhard Gebauer
Prof. Dr. Stefan Peiffer

Dynamics of soil processes under extreme meteorological boundary
conditions
-
Response of below-ground carbon, sulfur, and iron cycling in fen soils

Effects of experimental drought and subsequent rewetting on internal carbon, sulfur,
iron, and arsenic turnover in a soil from a northern temperate fen








Dynamik von Bodenprozessen bei extremen meteorologischen
Randbedingungen
-
Reaktion des Kohlenstoff-, Schwefel- und Eisenkreislaufes in einem
Niedermoor

Effekte experimenteller Austrocknung und Wiederbefeuchtung auf den internen
Kohlenstoff-, Schwefel-, Eisen- und Arsenumsatz in einem temperaten Niedermoor


Extended Summary







Acknowledgements
I would like to thank Christian Blodau for the supervision and advice during all phases of this work.
I would like to thank all members of the Hydrology department and all the assiduous student assistants
and technicians for their help. Without their support, this work would not have been possible: Stefan
Peiffer, Michael Radke, Marieke Oosterwoud, Beate Fulda, Martina Heider, Karin Söllner, Isolde
Baumann, Jutta Eckert, Martina Rohr, Heidi Zier, Likke Likke, Diana Burghardt, Tobias
Goldhammer, Tobias Heitmann, Markus Bauer, Marianna Deppe, Julia Beer, Jan Pfister, Björn
Thomas, Tobias Biermann, Severin Irl, Niklas Gassen, Benjamin Kopp, Lukas Gudmundsson,
Christine Mahler, Ireneusz Forys, Martin Back.
I would like to thank Bruno Glaser for the opportunity to measure stable carbon isotopes in his
laboratory; and Gerhard Gebauer and Stefanie Goldberg for analysis of isotope analysis in low
concentration samples.
I would like to thank the helpful coordinators and technicians of the Research Group FOR 562: Egbert
Matzner, Gunnar Lischeid, Werner Borken, Gerhard Müller, Gerhard Küfner, Uwe Hell, Andreas
Kolb.
I would like to thank all people providing advice and helpful comments, particularly Kirsten Küsel,
Marco Reiche, Markus Horn, Jörg Gelbrecht, Dominik Zak and many others.
I would like to thank my family for the support during all phases of my studies.
I would like to thank my wife Johanna for the help, love and trust.
1

Table of Contents

Table of Contents .................................................................................................................................... 1
List of Figures ......................................... 3
List of Tables ........................................... 4
Summary ................................................. 5
Zusammenfassung ................................... 7
1 Rationale ..................................... 9
2 Introduction .............................................................................................................................. 10
2.1 Impact of climate change on trace gas exchange of northern temperate peatlands .............. 10
2.2 Redox transformations and methanogenesis in peat soils .................................................... 11
2.3 Thermodynamics and carbon stable isotope signatures as tools to assess the effect of
experimental drought and rewetting on belowground carbon turnover ................................ 12
2.4 Arsenic mobilization and immobilization under variable redox conditions in a temperate fen
soil ........................................................................................................................................ 13
3 Research Objectives and Hypotheses ....................................................................................... 15
4 Materials and Methods ............................................................................................................. 16
4.1 Study site and treatments ...................................................................................................... 16
4.1.1 Design of the mesocosm experiment to study respiratory pathways, redox dynamics, and
carbon surface exchange in the laboratory ....................................................................... 16
4.1.2 Design of the field scale experiment to study below-ground redox dynamics under in-situ
conditions ......................................................................................................................... 18
4.2 Analytical techniques ........................................................................................................... 20
4.3 Calculations .......................................................................................................................... 21
5 Results and Discussion ............................................................................................................. 24
5.1 Effects of drought and rewetting on carbon fluxes of mesocosms from a temperate fen soil
(study 1) ................................................................................................................................ 24
5.2 Effects of drought and rewetting on redox transformations in a temperate fen soil (studies 2,
3, and 4) 26
5.2.1 Laboratory mesocosm scale (studies 2, 3) ........................................................................ 26
5.2.2 Field scale (study 4) .......................................................................................................... 29
5.3 Arsenic mobilization and immobilization under variable redox conditions in a temperate fen
soil (study 5) ......................................................................................................................... 30
5.4 Using carbon stable isotope signatures to assess the effect of experimental drought and
rewetting on belowground carbon turnover (study 3) .......................................................... 32
6 Conclusions .............................................................................................................................. 35
2

7 References ................................................................................................................................ 37
8 Contributions to the included manuscripts ............................................................................... 47
Study 1: Experimental drought alters rates of soil respiration and methanogenesis but not carbon
exchange in soil of a temperate fen .......................................................................................... 49
13Study 2: Fluxes and C isotopic composition of dissolved carbon and pathways of methanogenesis in
a fen soil exposed to experimental drought .............................................................................. 77
Study 3: Impact of experimental drought and rewetting on redox transformation in mesocosms of a
northern temperate fen soil ..................................................................................................... 107
Study 4: Dynamics of below-ground biogeochemistry in a minerotrophic fen exposed to a water table
manipulation ........................................................................................................................... 135
Study 5: Arsenic speciation and turnover in intact organic soil mesocosms during experimental
drought and rewetting ............................................................................................................. 165
Erklärung ............................................................................................................................................. 201

3

List of Figures
Fig. 1. Vol