Moorböden sind wirksame Speicher für Kohlenstoff (C) und damit bedeutend für das globale Klima. Naturnahe Moorböden mit hohen Wasserständen können beträchtliche Mengen an C akkumulieren. Durch Entwässerung verlieren sie ihre Netto-Senkenfunktion und setzen verstärkt C frei. Neben äußeren Umweltbedingungen spielt die Qualität der organischen Bodensubstanz (OBS) die entscheidende Rolle bei der C-Freisetzung aus Moorböden. Gegenwärtig fehlen allerdings detaillierte Daten, die Aussagen zur Qualität der OBS und zur potentiellen C-Freisetzung erlauben. Die vorliegende Arbeit untersucht die Qualität der OBS und das C-Freisetzungspotential ausgewählter Moorböden in Abhängigkeit von Bildungsbedingungen und Entwässerungsintensitäten mit unterschiedlichen methodischen Ansätzen. Mittels Infrarotspektroskopie konnten deutliche Unterschiede in den Absorptionsspektren zwischen Nieder- und Hochmoortorfen und zwischen unterschiedlich stark entwässerten Torfen gefunden werden. Um das C-Freisetzungspotential zu untersuchen, wurde die labile Fraktion der OBS bestimmt. Dafür wurde eine Methode zur Heißwasserextraktion organischer Böden entwickelt, die erfolgreich an Torfen unterschiedlicher Moorstandorte angewendet werden konnte. In einem weiteren Schritt wurde das Verhältnis von Gesamt-C zu OBS von Moorbodenhorizonten bestimmt. Die dabei gefundenen Abhängigkeiten von der jeweiligen Torfart und der Entwässerungsintensität belegen die Notwendigkeit für angepasste Umrechnungsfaktoren, um Fehler bei C-Bilanzierungen zu vermeiden. Außerdem wurde ein Entscheidungssystem zur Moortypenklassifikation sowie zur Berechnung der C-Speichermengen und C-Freisetzungspotentiale für Moorflächen unbekannten Typs entwickelt. Die Ergebnisse der vorliegenden Arbeit können zu einem besseren Verständnis von stofflichen Transformationen in Moorökosystemen beitragen. / Peatland soils store huge amounts of organic Carbon (C) and play a substantial role in the global climate system. Undisturbed peatlands with high water-tables accumulate significant C amounts. Through drainage, they change from C-sinks to C-sources. Beside various environmental factors, the quality of soil organic matter (SOM) strongly affects C-release out of peatland soils. Detailed data on SOM quality and potential C-release is currently missing. The present study investigates the quality of SOM and the C-release potential of selected peatland soils depending on building conditions and drainage intensities using various methodical approaches. With infrared spectroscopy, differences in absorption bands between fen and bog peats, as well as between peats under different influence of drainage could be found. The C release potential was investigated by determination of the labile fraction of SOM. For this purpose, a method for the hot-water-extraction of organic soils was developed and could successfully be applied for peats out of different sites. Additionally, organic C in relation to SOM was studied which showed clear relationships with peat types and level of drainage and demonstrates the need for an individual adaption of conversion factors when assessing C stocks. Furthermore, a decision support system for the determination of hydrogenetic mire types and the calculation of C-storages and C-release potentials of unknown peatland areas was developed. The results of the present study may contribute to a better understanding of organic matter transformation in peatlands.

Forest-cover in the tropics is changing rapidly due to indiscriminate removal of timber from many localities. The main focus of the study is to develop an operational tool for monitoring biomass and carbon pool of tropical forest ecosystems. The method was applied to a test site of Bangladesh. The research used Landsat ETM+, Landsat TM and IRS pan images of 2001, 1992 and 1999 respectively. Geometrically corrected Landsat ETM+ imagery was obtained from USGS and adjusted to the field using GPS. Historical images were corrected using image-to-image registration. Atmospheric correction was done by modified dark object subtraction method. Stratified sampling design based on the remote sensing image was applied for assessing the above-ground biomass and carbon content of the study area. Field sampling was done during 2002-2003. Dbh and height of all the trees inside the sample plots were measured. Field measurement was finally converted to carbon content using allometric relations. Three different methods: stratification, regression and k-nearest neighbors were tested for combining remote sensing image information and field-based terrestrial carbon pool. Additional field sampling was conducted during 2003-2004 for testing the accuracy. Finally regression method was selected. The amount of carbon released and sequestrated from the ecosystem was estimated. The application of the developed method would be quite useful for understating the terrestrial carbon dynamics and global climate change.

Forest-cover in the tropics is changing rapidly due to indiscriminate removal of timber from many localities. The main focus of the study is to develop an operational tool for monitoring biomass and carbon pool of tropical forest ecosystems. The method was applied to a test site of Bangladesh. The research used Landsat ETM+, Landsat TM and IRS pan images of 2001, 1992 and 1999 respectively. Geometrically corrected Landsat ETM+ imagery was obtained from USGS and adjusted to the field using GPS. Historical images were corrected using image-to-image registration. Atmospheric correction was done by modified dark object subtraction method. Stratified sampling design based on the remote sensing image was applied for assessing the above-ground biomass and carbon content of the study area. Field sampling was done during 2002-2003. Dbh and height of all the trees inside the sample plots were measured. Field measurement was finally converted to carbon content using allometric relations. Three different methods: stratification, regression and k-nearest neighbors were tested for combining remote sensing image information and field-based terrestrial carbon pool. Additional field sampling was conducted during 2003-2004 for testing the accuracy. Finally regression method was selected. The amount of carbon released and sequestrated from the ecosystem was estimated. The application of the developed method would be quite useful for understating the terrestrial carbon dynamics and global climate change.