ALBERT

Note: Table of contents Abstract Zusammenfassung 1 Motivation 2 Introduction 2.1 Arctic climate changes and their impacts on Coastal processes 2.2 Shoreline retreat along Arctic coasts 2.3 Impacts of Coastal erosion 2.3.1 Material fluxes 2.3.2 Retrogressive thaw slumps 2.3.3 Socio-economic impacts 2.4 Objectives 2.5 Study area 2.6 Thesis structure 2.7 Authors’ contributions 3 Variability in rates of Coastal change along the Yukon coast, 1951 to 2015 3.1 Introduction 3.2 Study Area 3.3 Data and Methods 3.3.1 Remote sensing data 3.3.2 Field survey data 3.3.3 Classification of shoreline 3.3.4 Transect-wise analyses of shoreline movements through time 3.4 Results 3.4.1 Temporal variations in shoreline change rates 3.4.2 Alongshore rates of change 3.4.3 Shoreline dynamics along field sites 3.4.4 Dynamics of lagoons, barrier Islands and spits (gravel features) 3.4.5 Yukon Territory land loss 3.5 Discussion 3.5.1 Temporal variations in shoreline change rates 3.5.2 Alongshore rates of change 3.5.3 Dynamics of lagoons, barrier Islands, and spits (gravel features) 3.5.4 Expected shoreline changes as a consequence of future climate warming 3.6 Conclusions Context 4 Coastal erosion of permafrost Solls along the Yukon Coastal Plain and Kuxes oforganic carbon to the Canadian Beaufort Sea 4.1 Introduction 4.2 Study Area 4.3 Methods 4.3.1 Sample collection and laboratory analyses 4.3.2 Soll organic carbon determinations 4.3.3 Flux of organic soil carbon and Sediments 4.3.4 Fate of the eroded soil organic carbon 4.4 Results 4.4.1 Ground lce 4.4.2 Organic carbon contents 4.4.3 Material fluxes 4.5 Discussion 4.5.1 Ground lce 4.5.2 Organic carbon contents 4.5.3 Material fluxes 4.5.4 Organic carbon in nearshore Sediments 4.6 Conclusion Context 5 Terrain Controls on the occurrence of Coastal retrogressive thaw slumpsalong the Yukon Coast, Canada 5.1 Introduction 5.2 Study Area 5.3 Methods 5.3.1 Mapping of RTSs and landform Classification 5.3.2 Environmental variables 5.3.3 Univariate regression trees 5.4 Results 5.4.1 Characteristics of RTS along the coast 5.4.2 Density and areal coverage od RTSs along the Yukon Coast 5.5 Discussion 5.5.1 Characteristics and distribution of RTSs along the Yukon Coast 5.5.2 Terrain factors explaining RTS occurrence 5.5.3 Coastal processes 5.6 Conclusions Context 6 Impacts of past and fiiture Coastal changes on the Yukon coast - threats forcultural sites, infrastructure and travel routes 6.1 Introduction 6.2 Study Area 6.3 Methods 6.3.1 Data for shoreline projections 6.3.2 Shoreline projection for the conservative scenario (S1) 6.3.3 Shoreline Projection for the dynamic scenario (S2) 6.3.4 Positioning and characterizing of cultural sites 6.3.5 Calculation of losses under the S1 and S2 scenarios 6.3.6 Estimation of future dynamics in very dynamic areas 6.4 Results and discussion 6.4.1 Past and future shoreline change rates 6.4.2 Cultural sites 6.4.3 Infrastructure and travel routes 6.5 Conclusions 7 Discussion 7.1 The importance of understanding climatic drivers of Coastal changes 7.2 The influence of shoreline change rates on retrogressive thaw slump activity 7.3 On the calculation of carbon fluxes from Coastal erosion along the Yukon coast 7.4 Impacts of present and future Coastal erosion on the natural and human environment 7.5 Synthesis 8 Summary and Conclusions Bibliography Supporting Material Data Set ds01 Table S1 Table S3 Abbreviations and Nomendature Acknowledgements

Note: Table of Contents Abstract Zusammenfassung List of Figures List of Tables 1. Introduction 1.1 Scientific Background 1.1.1 Arctic Climate Change 1.1.2 Permafrost Degradation 1.1.3 The Arctic Freshwater System and its Biogeochemistry 1.2 Objectives 1.3 Study Region and Methods 1.3.1 Study Area 1.3.2 Field Sampling and Measurements 1.3.3 Geochemical Analyses 1.3.4 Data Processing 1.4 Thesis Structure 1.5 Author Contributions 2. Spatial Variability of Dissolved Organic Carbon, Solutes and Suspended Sediment in Disturbed Low Arctic Coastal Watersheds 2.1 Abstract 2.2 Introduction 2.3 Study Site 2.4 Methods 2.4.1 Stream Monitoring 2.4.2 Mapping of Disturbances 2.4.3 Flux Estimates and Statistics 2.5 Results 2.5.1 Catchment Disturbance 2.5.2 Runoff and Hydrochemistry 2.5.3 Lateral Transport of Stream Water 2.5.4 Hydrochemical Composition and Fluxes in Nearby Streams 2.6 Discussion 2.6.1 Total Runoff and Water Quality 2.6.2 Water Quality Changes from Headwaters to Downstream 2.6.3 Changes in Hydrochemistry and Isotopic Composition over Time 2.6.4 Importance of Disturbances for Hydrochemistry 2.7 Conclusions 2.8 Supplementary Material 3. Terrestrial Colored Dissolved Organic Matter (cDOM) in Arctic Catchments - Characterizing Organic Matter Composition Across the Arctic 3.1 Introduction 3.2 Study Area 3.3 Methods 3.3.1 Field Methods and Hydrochemistry 3.3.2 Statistical Analyses 3.4 Results 3.4.1 Meteorological Conditions and General Hydrochemistry 3.4.2 DOC and cDOM Absorption Characteristics 3.4.3 Downstream Patterns of DOC and cDOM Along Longitudinal Transects 3.4.4 Temporal Trends ofDOC and cDOM with Changing Meteorological Conditions 3.5 Discussion 3.5.1 Limitations of cDOM Measurements from Terrestrial Sources 3.5.2 Catchment Processes and Biogeochemical Cycling 3.5.2.1 Regional Catchment Properties 3.5.2.2 Rainfall Events 3.5.2.3 Downstream Patterns and Impact of Permafrost Disturbance 3.5.3 Nature of cDOM-DOC Across the Terrestrial Arctic 3.6 Conclusion 3.7 Supplementary Material 4. Summer Rainfall DOC, Solute and Sediment Fluxes in a Small Arctic Coastal Catchment on Herschel Island (Yukon Territory, Canada) 4.1 Abstract 4.2 Introduction 4.3 Study Site 4.4 Methodology 4.4.1 Weather data 4.4.2 Hydrology 4.4.3 Suspended Sediment and Hydrochemistry 4.4.4 Flux Estimates and Statistics 4.5 Results 4.5.1 Meteorological Conditions 4.5.2 Streamflow and Electrical Conductivity 4.5.3 Transport of Suspended Sediment and Organic Matter 4.5.4 Solute Transport 4.5.5 Alluvial Fan Sampling 4.6 Discussion 4.6.1 Hydrological Response 4.6.2 Water Quality and Fluxes 4.6.3 Rainfall Response and Flow Pathways 4.7 Conclusions 4.8 Supplementary Material 5. Synthesis 5.1 Impacts of Permafrost Degradation on Stream Biogeochemistry 5.2 Controls on DOM Quality across the Arctic 5.3 Biogeochemical Fluxes from Small Coastal Catchments to the Arctic Ocean 5.4 Challenges 5.5 Outlook Acronyms Bibliography Acknowledgements Eidesstattliche Erklärung

Note: Dissertation, Universität Potsdam, 2020 , Table of contents Abstract Kurzfassung Table of contents Chapter 1: Introduction 1.1 The challenge of proxy uncertainties 1.2 Aims and approaches 1.3 Thesis outline and author's contributions Chapter 2: Comparing methods for analysing time scale dependent correlations in irregularly sampled time series data 2.1 Abstract 2.2 Introduction 2.3 Methods 2.3.1 Time scale dependency 2.3.2 Irregularity 2.3.3 Surrogate data 2.3.3.1 Construction of surrogate signals 2.3.3.2 Construction of irregular sampling 2.3.4 Evaluation of the estimation methods 2.4 Results 2.4.1 Correlation of red signal - white noise time series 2.4.2 Correlation of white signal - white noise time series 2.5 Discussion 2.5.1 Effect of irregularity and non-simultaneousness in sampling 2.5.2 Choosing the best method 2.5.2.1 Handling irregularity 2.5.2.2 Accounting for time scale dependency 2.5.3 Example application to observed proxy records 2.6 Conclusion 2.7 Computer code availability 2.8 Acknowledgements 2.9 Appendix 2-A. Significance test for time scale dependent correlation estimates Chapter 3: Empirical estimate of the signal content of Holocene temperature proxy records 3.1 Abstract 3.2 Introduction 3.3 Data 3.3,1 Proxy records 3.3.2 Climate model simulations 3.4 Method 3.4.1 Approach and assumptions 3.4.2 Spatial correlation structure of model vs. reanalysis data 3.4.3 Processing steps 3.4.3.1 Estimation of the spatial correlation structure 3.4.3.2 Estimation of the SNRs 3.5 Results 3.5.1 Spatial correlation structure and correlation decay length 3.5.2 SNR estimates 3.6 Discussion 3.6.1 Spatial correlation structure of model simulations 3.6.2 Finite number of proxy records 3.6.3 Proxy-specific recording of climate variables 3.6.4 Time uncertainty and non-climatic components of the proxy signal 3.6.5 Implications and future steps forward 3.7 Conclusion 3.8 Code availability 3.9 Data availability 3.10 Acknowledgements Chapter 4: Testing the consistency of Holocene and Last Glacial Maximum spatial correlations in temperature proxy records 4.1 Abstract 4.2 Introduction 4.3 Data 4.4 Method 4.4.1 Approach and assumptions 4.4.2 Holocene and LGM spatial correlation structure from climate model simulation 4.4.3 Effect of changes in climate variability on the predicted correlations 4.4.4 Effect of changes in time uncertainty on the predicted correlations 4.4.S Estimating the surrogate-based LGM spatial correlation and accounting for parameter uncertainty 4.5 Results 4.6 Discussion 4.6.1 Proxy-specific recording and finite number of records 4.6.2 Time uncertainty of proxy records 4.6.3 Contrary behaviour of U K'37 records 4.6.4 Spatial correlation structure and orbital trends 4.7 Conclusion 4.8 Acknowledgements 4.9 Appendix 4-A. Deriving the effect of a different signal variance on the correlation Chapter 5: Synthesis 5.1 Irregular sampling and time scale dependent correlations 5.2 Spatial correlation structure of proxy records 5.3 Consistency of spatial correlations for different climate states 5.4 Signal content of proxy records 5.5 Concluding remarks and Outlook Chapter A: Supplement of Chapter 3 - Empirical estimate of the signal content of Holocene temperature proxy records A.1 Supplementary Figures A.2 Supplementary Tables Chapter B: Supplement of Chapter 4 - Testing the consistency of Holocene and Last Glacial Maximum spatial correlations of temperature proxy records 8.1 Supplementary Figures 8.2 Supplementary Tables References Danksagung Eidesstattliche Erklärung

Note: Dissertation, Universität Potsdam, 2020 , Contents Preface Acknowledgements Contents Summary Zusammenfassung List of abbreviations Chapter 1. Introduction 1.1 Motivation 1.2 Carbon storage in Arctic permafrost environments and the permafrost carbon feedback (PCF) 1.3 Methane cycling microorganisms 1.4 The microbial ecology of permafrost 1.5 Plasmids and their potential role in stress tolerance 1.6 Objectives Chapter 2. Study sites 2.1 Regional settings 2.2 Kurungnakh and Samoylov Island 2.3 Bol'shoy Lyakhovsky Island 2.4 Herschel Island Chapter 3. Manuscripts 3.1 Overview of manuscripts, including contribution of co-authors. 3.2 Manuscript I Methanogenic response to long-term permafrost thaw is determined by paleoenvironment 3.3 Manuscript II Methane production in thawing permafrost is constrained by methanogenic population size and carbon density 3.4 Manuscript III Metaplasmidome-encoded functional potential of permafrost active layer soils Chapter 4. Synthesis 4.1 Introduction 4.2 Constraints behind methane production from thawing permafrost 4.3 The methanogenic community response to long-term permafrost thaw 4.4 The adaptive potential of the permafrost micro biota to cope with stress factors during global warming 4.5 Conclusion Chapter 5. Future research directions and perspectives Chapter 6. References Chapter 7. Appendix 7.1 Supporting information for manuscript I 7.2 Supporting information for manuscript II 7.3 Supporting information for manuscript III 7.4 ESR collaboration, manuscript IV

Note: Dissertation, Universität Potsdam, 2023 , TABLE OF CONTENTS Acknowledgements Summary Zusammenfassung 1 General introduction 1.1 A changing world 1.1.1 Global changes of anthropogenic origin 1.1.2 Amplified crisis in the high latitudes 1.2 The past is the key to the future 1.2.1 The Quaternary glacial and interglacial stages 1.2.2 The Beringia study case 1.3 Investigating past biodiversity 1.3.1 Traditional tools 1.3.2 Newest sedaDNA proxies 1.4 Motivation and aims of the thesis 1.5 Structure of the thesis 1.6 Author’s contributions 2 Manuscript I 2.1 Abstract 2.2 Introduction 2.3 Materials and Methods 2.3.1 Geographical settings 2.3.2 Fieldwork and subsampling 2.3.3 Core splicing and dating 2.3.4 Sediment-geochemical analyses 2.3.5 Pollen analysis 2.3.6 Molecular genetic preparation 2.3.7 Processing of sedaDNA data 2.3.8 Statistical analysis and visualization 2.4 Results 2.4.1 Age model 2.4.2 Sediment-geochemical core composition 2.4.3 Pollen stratigraphy 2.4.4 sedaDNA composition 2.4.5 Comparison between pollen and sedaDNA 2.4.6 Taxa richness investigation 2.5 Discussion 2.5.1 Proxy validation 2.5.2 Vegetation compositional changes in response to climate inferred from pollen and sedaDNA records 2.5.3 The steppe-tundra of the Late Pleistocene 2.5.4 The disrupted Pleistocene-Holocene transition 2.5.5 The boreal forest of the Holocene 2.5.6 Changes in vegetation richness through the Pleistocene/Holocene transition inferred from the sedaDNA record 2.6 Conclusion Data availability statement Funding References 3 Manuscript II 3.1 Abstract 3.2 Introduction 3.3 Material and Method 3.3.1 Site description and timeframe 3.3.2 Sampling, DNA extraction and PCR 3.3.3 Filtering and cleaning dataset 3.3.4 Identification of taxa – species signal 3.3.5 Resampling 3.3.6 Assessment of the species pool stability 3.3.7 Quantification of extinct and extirpated taxa 3.3.8 Characterisation of species and candidate species 3.4 Results 3.4.1 Changes in the composition and species pool at the Pleistocene - Holocene transition 3.4.2 Decrease in the regional plant species richness between the Pleistocene and the Holocene 3.4.3 Identification of loss taxa events 3.4.4 Characterisation of lost taxa 3.5 Discussion 3.5.1 Biotic and abiotic changes in the ecosystem - a cocktail for extinction 3.5.2 Identification and quantification of potential plant taxa loss 3.5.3 Characterisation of potential taxa loss 3.5.4 Limits of the method 3.5.5 Conclusions and perspectives Funding References 4 Manuscript III 4.1 Abstract 4.2 Introduction 4.3 Material & Methods 4.3.1 Fieldwork and subsampling 4.3.2 Chronology 4.3.3 Pollen analysis 4.3.4 Isolation of sedimentary ancient DNA 4.3.5 Metabarcoding approach 4.3.6 Shotgun approach 4.3.7 Bioinformatic processing 4.4 Results 4.4.1 General results of the three approaches: pollen, metabarcoding and shotgun sequencing 4.4.2 Plants (Viridiplantae) 4.4.3 Fungi 4.4.4 Mammals (Mammalia) 4.4.5 Birds (Aves) 4.4.6 Insects (Insecta) 4.4.7 Prokaryotes (Bacteria, Archaea) and Viruses 4.5 Discussion 4.5.1 Interglacial communities 4.5.2 Glacial communities 4.5.3 Potential and limitations of the sedaDNA shotgun approach applied to ancient permafrost sediments 4.6 Conclusions Data availability statement Funding References 5 Synthesis 5.1 Ecological changes between glacial and interglacial stages 5.1.1 Changes in the compositional structure 5.1.2 Loss of plant diversity 5.1.3 Potential drivers of change 5.2 High potential of sedaDNA for past biodiversity reconstruction 5.3 Conclusions and future perspectives Bibliography Appendices Appendix 1: Supplementary material for Manuscript I Appendix 2: Supplementary material for Manuscript II Appendix 3: Supplementary material for Manuscript III Appendix 4: Manuscript IV Eidesstattliche Erklärung

Note: Inhaltsverzeichnis: 1. Einleitung. - 2. Atmosphärische Gleichungssysteme. - 2.1. Zur Notation. - 2.2. Geometrie im β-Kanal. - 2.3. Gleichungen in Flussform. - 2.4. Euler-Gleichungen. - 2.4.1. Energiegleichung. - 2.4.2. Bewegungsgleichungen. - 2.4.3. Flussform des gesamten Gleichungssystems. - 2.4.4. Schallgeschwindigkeit. - 2.4.5. Druck und Energie. - 2.4.6. Energie als Erhaltungsvariable. - 2.5. Euler-Gleichungen mit Referenzfeld. - 2.6. Linearisierte Euler-Gleichungen. - 2.7. Flachwassergleichungen. - 2.8. Flachwasseräquivalente Dynamik mit Euler-Gleichungen. - 3. Unstetiges Galerkin-Verfahren. - 3.1. Räumliche Diskretisierung. - 3.1.1. Integralform und numerischer Fluss. - 3.1.2. Koeffizientendarstellung der Gleichungen. - 3.1.3. Koordinatentransformation mit Orographie. - 3.1.4. Quadratur. - 3.1.5. Basisfunktionen im Rechteckgitter. - 3.1.6. Diskretisierung von analytischen Anfangsbedingungen. - 3.2. Zeitliche Diskretisierung. - 3.2.1. Expliziter Zeitschritt. - 3.2.2. Semi-impliziter Zeitschritt. - 3.2.3. Skalierung von Einheiten. - 3.2.4. Zeitschrittbestimmung. - 3.3. Randbedingungen. - 3.3.1. Periodische Randbedingungen. - 3.3.2. Reflektive Randbedingungen. - 3.3.3. Spezifische Randbedingungen für Euler-Gleichungen. - 3.3.4. Absorptionsschicht. - 3.4. Diffusion. - 4. Atmosphärische Gleichgewichtszustände. - 4.1. Anforderungen an stationäre Zustände. - 4.1.1. Verschwindende Advektion von Masse und potentieller Temperatur. - 4.1.2. Stationäre Impulsgleichung. - 4.2. Wind ohne Corioliskraft. - 4.3. Geostrophischer Wind. - 4.4. Vorgegebener Grundstrom mit einstellbarer Baroklinität. - 4.4.1. Lösungsalgorithmus. - 4.4.2. Zulässige Windfelder und ihre Definition außerhalb des Modellgebietes. - 4.4.3. Spezialfall konstanten thermischen Windes. - 4.5. Barotroper Grundstrom als analytischer Spezialfall. - 4.6. Charakterisierung der Baroklinität. - 4.7. Geostrophischer Zustand für Flachwassergleichungen. - 5. Numerische Stabilität von Gleichgewichtszuständen und Erhaltungseigenschaften. - 5.1. Polynomiale Balancierung des DG-Verfahrens. - 5.1.1. Ausgangssituation („low0bal0“). - 5.1.2. Isotrope Reduktion des Polynomgrades der Quellterme („low1bal0“). - 5.1.3. Isotrope Polynomgradreduktion von Quelltermen sowie Projektion der Flussfunktion („low1bal1“). - 5.1.4. Volle Balancierung mit selektiver Polynomgradreduktion und Projektion der Flussfunktion („low2bal1“). - 5.2. Konvergenz. - 5.3. Langzeitstabilität und Erhaltungseigenschaften. - 6. Atmosphärische Testfälle. - 6.1. Aufsteigende warme Blase. - 6.2. Schwerewellen. - 6.3. Bergüberströmung. - 6.4. Barotrope Instabilität. - 7. Atmosphärische Instabilitäten in mittleren Breiten. - 7.1. Barotrope Instabilität mit Euler-Gleichungen in 2D und 3D. - 7.1.1. Wavelet-Spektrum. - 7.2. Barokline Instabilität in Abhängigkeit von statischer Stabilität und thermischem Wind. - 7.2.1. Einfluss der statischen Stabilität. - 7.2.2. Einfluss der vertikalen Diskretisierung. - 7.3. Entstehung zyklonaler Wirbel aus baroklin instabilem Grundstrom. - 7.3.1. Konfiguration. - 7.3.2. Entwicklung von Impulsdifferenz. - 7.3.3. Vorticity im Horizontalschnitt. - 7.3.4. Globale Charakterisierung . - 7.4. Langzeitentwicklung aus baroklinen Zuständen. - 7.4.1. Konfiguration. - 7.4.2. Entwicklung von Impulsdifferenz und Energie. - 7.4.3. Vorticity im Horizontalschnitt. - 7.4.4 Globale Charakterisierung. - 7.4.5. Wavelet-Spektrum. - 7.4.6. Zonales Mittel. - 8. Zusammenfassung und Ausblick. - A. Mathematische Aspekte. - A.1. Profilfunktionen. - A.2. Differenzen und Normen. - A.3. Wavelet-Analyse. - A.4. Darstellung aus der Diskretisierung. - A.5. Erhaltungseigenschaften mit Quadratur. - B. Details zu Euler-Gleichungen. - B.1. Vertikale Linearisierung der Euler-Gleichungen für Präkonditionierer des semi-impliziten Zeitschrittes. - B.1.1. Vertikales lineares Gleichungssystem. - B.1.2. Diskretisierung und Matrizen. - B.1.3. Implizites Gleichungssystem. - B.2. Zustände im hydrostatischen Gleichgewicht. - B.2.1. Isotherm. - B.2.2. Polytrop. - B.2.3. Isentrop. - B.2.4. Mehrfach polytrop. - B.2.5. Uniform geschichtet. - B.3. Barokliner Zustand imp-System. - C. Zusätzliche Simulationsdaten. - C.1. Stabilitätskarten zu baroklinen Langzeitsimulationen. - C.2. Wirbelentstehung nahe Oberrand. - C.3. Zusätzliche Horizontalschnitte des baroklinen Langzeitlaufes. - D. Implementierung: Programmpaket Polyflux. - E. Korrekturen zur Veröffentlichung. - Mathematische Definitionen. - Abkürzungen und Begriffe. - Literatur.

Note: TABLE OF CONTENTS Abstract Kurzfassung Table of Contents List of Figures List of Tables List of Abbreviations List of Symbols 1 INTRODUCTION 1.1 Background and Scientific Setting 1.2 Motivation and Research Questions 1.3 Structure of Thesis 2 FUNDAMENTALS OF HYPERSPECTRAL AND SPECTRO-DIRECTIONAL REMOTE SENSING 2.1 Hyperspectral Remote Sensing of Vegetation 2.2 Spectro-Directional Remote Sensing of Vegetation 2.3 The EnMAP Satellite System 2.4 Spectro-Goniometer Systems for the Ground-Based Measurement of BRDF Effects 3 THE TUNDRA PERMAFROST STUDY LOCATIONS AND THEIR ENVIRONMENT 3.1 The Eurasia Arctic Transect (EAT) 3.1.1 Geological and Climatic Setting 3.1.2 Vegetation 3.2 The North American Arctic Transect (NAAT) 3.2.1 Geological and Climatic Setting 3.2.2 Vegetation 4 OBSERVATIONS AND METHODOLOGY 4.1 Observations Used for this Study 4.1.1 The ECI-GOA-Yamal 2011 Expedition 4.1.2 The EyeSight- NAAT-Alaska 2012 Expedition 4.1.3 Data Used for Hyperspectral Characterization of Arctic Tundra 4.1.4 Data Used for Spectro-Directional Characterization of Arctic Tundra 4.2 Methodology Used for Field Work and Data Analysis 4.2.1 Field Spectroscopy and Hyperspectral Data Analysis 4.2.2 Considerations for the Field Spectro-Goniometer Measurements and the Spectro-Directional Data Analysis 5 DEVELOPMENT AND PRECOMMISSIONING INSPECTION OF THE MANTIS FIELD SPECTRO-GONIOMETER 5.1 Introduction 5.2 Theoretical Background 5.3 Description of the Field Spectro-Goniometer System 5.3.1 Construction Schedule 5.3.2 Description of the Field Spectro-Goniometer Platform (ManTIS) 5.3.3 Sensor Configuration of the AWI ManTIS Field Spectro-Goniometer 5.3.4 Measurement Strategy 5.3.5 Software for Semi-Automatic Control 5.4 Error Assessment 5.4.1 Radiometrical Accuracy 5.4.2 Pointing Accuracy 5.4.3 Ground Instantaneous Field of View and Sensor Self-Shadowing 5.4.4 Temporal Illumination Changes and Environmental Influences 5.5 Data Analysis 5.5.1 Data Processing 5.5.2 Data Visualization 5.6 Performance of ManTIS Field Spectro-Goniometer in the Field 5.6.1 Test Site and Experiment Setup 5.6.2 Results and Discussion 5.7 Conclusions and Outlook 6 HYPERSPECTRAL REFLECTANCE CHARACTERIZATION OF LOW ARCTIC TUNDRA VEGETATION 6.1 Introduction 6.2 Material & Methods 6.2.1 Study Area 6.2.2 Environmental Gradients/Zones and Vegetation Description 6.2.3 Data Acquisition and Pre-Processing 6.2.4 Data Analysis 6.3 Results 6.3.1 The Zonal Climate Gradient 6.3.2 Acidic Versus Non-Acidic Tundra (Soil pH Zones) 6.3.3 The Toposequence at Happy Valley (Subzone E) 6.3.4 The Soil Moisture Gradient at Franklin Bluffs (Subzone D) 6.4 Discussion 6.4.1 Overview of Field Characterization and Spectral Properties along the Gradients 6.4.2 Performance of Spectral Metrics and Vegetation Indices 6.5 Conclusions 7 RESULTS OF THE SPECTRO-DIRECTIONAL REFLECTANCE INVESTIGATIONS 7.1 Overview of the Spectro-Directional Reflectance Characteristics of Low Arctic Tundra Vegetation 7.1.1 Representativeness of the Study Plots Representing Tundra Vegetation 7.1.2 Vaskiny Dachi – Bioclimate Subzone D 7.1.3 Happy Valley – Bioclimate Subzone E 7.1.4 Franklin Bluffs – Bioclimate Subzone D 7.2 Influence of High Sun Zenith Angles on the Reflectance Anisotropy 7.2.1 MAT (Happy Valley) 7.2.2 MNT (Franklin Bluffs) 7.3 Variability in Multi-Angular Remote Sensing Products of Low Arctic Tundra Environments 7.3.1 Spectro-Directional Variability of Different Low Arctic Plant Communities 7.3.2 Spectro-Directional Variability under Varying Sun Zenith Angles 8 DISCUSSION 8.1 The Hyperspectral Reflectance Characteristics of Tundra Vegetation in Context of the Spectro-Goniometer Measurements 8.2 Applicability of the ManTIS Field Spectro-Goniometer System 8.3 The Spectro-Directional Reflectance Characteristics of Tundra Vegetation 8.4 Variability in Reflectance Anisotropy at High Sun Zenith Angles 8.5 Applicability of Multi- Angular Remote Sensing Products for Arctic Tundra Environments 9 CONCLUSIONS & OUTLOOK Acknowledgments References Appendix Table of Contents of the Appendix References of the Appendix Statutory Declaration / Eidesstattliche Erklärung

Note: Table of content Abstract Zusammenfassung 1. Introduction 1.1. Motivation 1.2. Scientific Background 1.2.1. Permafrost in arctic environments 1.2.2. Carbon storage and emission in arctic environments 1.2.3. Methane cycling in arctic environments 1.3. Study Sites 1.3.1. Lena-Delta, Siberia 1.3.2. El’gygytgyn Crater Lake, Chukotka 1.4. Objectives and approach 1.5. Thesis organization 1.6. Summary of the included manuscripts and contribution of the co-authors 1.6.1. Response of methanogenic archaea to Late Pleistocene and Holocene climate changes in the Siberian Arctic 1.6.2. Response of microbial communities to landscape and climatic changes in a terrestrial permafrost sequence of the El’gygytgyn crater, Far East Russian Arctic 1.6.3. Glacial-interglacial microbial community dynamics in Middle Pleistocene sediments in the Lake El’gygytgyn, Far East Russian Arctic 2. Response of methanogenic archaea to Late Pleistocene and Holocene climate changes in the Siberian Arctic 2.1. Abstract 2.2. Introduction 2.3. Materials and Methods 2.3.1. Study site 2.3.2. Permafrost drilling and sample preparation 2.3.3. Sediment properties 2.3.4. Potential methane production rates 2.3.5. Lipid biomarker analysis 2.3.6. Detection of archaeol and isoprenoid GDGTs 2.3.7. Detection of PLFAs and PLELs 2.3.8. DNA extraction and polymerase chain reaction (PCR) amplification 2.3.9. Phylogenetic analysis 2.4. Results and Discussion 2.4.1. Methane profile of the Kurungnakh permafrost sequence 2.4.2. Signals of living microbial communities in the Kurungnakh permafrost sequence 2.4.3. Reconstruction of past microbial communities in the Kurungnakh permafrost sequence 2.4.4. Climate impact on the distribution of microbial communities in the Kurungnakh permafrost sequence 2.4.5. Climatic impact on the composition of methanogenic communities in the Kurungnakh permafrost sequence 2.5. Conclusion 2.6. Acknowledgement 3. Response of microbial communities to landscape and climatic changes in a terrestrial permafrost sequence of the El’gygytgyn crater, Far East Russian Arctic 3.1. Abstract 3.2. Introduction 3.3. Materials and Methods 3.3.1.Study site 3.3.2. Drilling and sample material 3.3.3. Sediment properties 3.3.4. Lipid biomarker analysis 3.3.5. Detection of glycerol dialkyl glycerol tetraethers (GDGTs) and archaeol 3.3.6. Detection of phospholipid fatty acids (PLFA) 3.3.7. Deoxyribonucleic acid (DNA) extraction and amplification 3.3.8. Quantitative PCR analysis of archaeal and bacterial small sub unit (SSU) rRNA genes 3.3.9. Phylogenetic analysis 3.4. Results 3.4.1. TOC-contents 3.4.2. Distribution of glycerol dialkyl glycerol tetraethers (GDGTs) and archaeol 3.4.3. Distribution of phospholipid fatty acids (PLFA) 3.4.4. Composition of archaeol and isoprenoid GDGTs 3.4.5. Quantification of bacterial and archaeal genes 3.4.6. Analysis of methanogenic community fingerprints 3.5. Discussion 3.5.1. Microbial communities in subaquatic deposits 3.5.2. Microbial communities in subaerial deposits 3.5.3. Microbial succession in the Holocene sequence of Lake El’gygytgyn permafrost 3.6.Conclusion 3.7. Acknowledgements 4. Glacial-interglacial microbial community dynamics in Middle Pleistocene sediments in the Lake El’gygytgyn, Far East Russian Arctic 4.1. Abstract 4.2. Introduction 4.3. Materials and Methods 4.3.1. Study site 4.3.2. Drilling and sample preparation 4.3.3. Sediment properties 4.3.4. Lipid biomarker analyses 4.3.5. Deoxyribonucleic acid (DNA) extraction and quantitative polymerase chain reaction (qPCR) 4.3.6. PCR amplification of methanogenic SSU rRNA genes 4.4. Results 4.4.1. Sedimentary TOC and biogenic silica concentration 4.4.2. Quantification of bacterial and archaeal genes 4.4.3. Quantification and composition of lipid biomarkers 4.4.4. Potential methane production 4.4.5. Methanogenic community composition 4.5. Discussion 4.6. Acknowledgements 5. Synthesis 5.1. The reaction of microbial communities to past climatic change in the Arctic 5.2.The response of microbial communities to carbon composition and availability 5.3. Implications from this study for future research 6. Data collection 6.1. Manuscript I: Response of methanogenic archaea to Late Pleistocene and Holocene climate changes in the Siberian Arctic 6.1.1. Sediment properties 6.1.2. Isoprenoid glycerol dialkyl glycerol tetraethers and archaeol 6.1.3. Branched glycerol dialkyl glycerol tetraethers 6.1.4. Phospholipid ester and ether lipids (summary) 6.2. Manuscript II: Response of microbial communities to landscape and climatic changes in a terrestrial permafrost sequence of the El’gygytgyn crater, Far East Russian Arctic 6.2.1. Sediment properties and gene quantifications 6.2.2. Phospholipid fatty acids composition 6.2.3. Isoprenoid glycerol dialkyl glycerol tetraethers and archaeol 6.2.4. Branched glycerol dialkyl glycerol tetraethers 6.3. Manuscript III: Glacial-interglacial microbial community dynamics in Middle Pleistocene sediments in the Lake El’gygytgyn, Far East Russian Arctic 6.3.1. Sediment properties and gene quantifications 6.3.2. Isoprenoid glycerol dialkyl glycerol tetraethers and archaeol 6.3.3. Branched glycerol dialkylglycerol tetraethers 7. References 8. Final thoughts and acknowledgements 9. Curriculum vitae 10.Erklärung