Spatial variability and seasonal dynamics of dissolved organic matter in surface and soil pore waters in mire-forest landscapes in the Komi Republic, Northwest-Russia

• Main Author: Avagyan, Armine
• Other Authors: Kutzbach, Lars (Prof. Dr.)
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky 2013
• Subjects: peatland; dissolved organic matter; hydrochemistry; 550 Geowissenschaften; 38.60 Bodenkunde: Allgemeines; 38.85 Hydrologie: Allgemeines; 38.95 Umweltgeologie; Geoökologie; gelösten organischen Kohlenstoff; Sumpf-Komplex; Moor; ddc:550; Russland; Northwest Russia
• Online Access: http://nbn-resolving.de/urn:nbn:de:gbv:18-64108; https://ediss.sub.uni-hamburg.de/handle/ediss/5118

The overarching aim of this thesis is to describe and contribute to the still rather sparse data on the small-scale spatial variability and seasonal dynamics of dissolved organic matter (DOM) in the surface and soil pore waters in mire-forest landscapes in the Komi Republic of Northwest Russia. This study stands out because it estimates the DOC flux during the snowmelt and identifies the main ecohydrological units that contribute to the flux. Furthermore, this study aims to bridge the gap between the knowledge of DOM fluxes and different size fractions of organic carbon (truly dissolved and colloidal) in a boreal mire-forest landscape. It also provides comparative analyses of different portable DOC measurement methods, which is important for evaluating DOC dynamics in remote sites. This thesis consists of eight chapters. Chapter 1 presents the Introduction, which highlights the current gaps in our knowledge of DOM dynamics. Additionally, it presents the motivations, principle objectives and scope of the investigation. Chapter 2 provides a literature review of the importance of peatlands as carbon sinks and highlights the role of dissolved organic carbon (DOC), the main component of lateral carbon fluxes, in predicting the possible responses to global change and other effects on biochemical cycles. In addition, Chapter 2 describes the structural characteristics of DOM and the primary regulatory factors that cause changes in DOM concentrations. Chapter 3 provides detailed information about the study site for the conducted research that is described in Chapters 4-7. The description includes information about the location, geology, climatic data and vegetation of the site. The main findings of this thesis are presented in Chapters 4-7. Each of these chapters consists of separate sections: abstract, introduction, materials and methods, results, discussion and conclusions. The primary objective of Chapter 4 is to provide a comparative study of innovative methods for measuring DOC under remote field conditions. The ...