Impact of environmental factors on key functional groups involved in nitrogen cycling in agricultural ecosystems [Elektronische Ressource] / vorgelegt von Brigitte Hai

Impact of Environmental Factors on Key Functional Groups involved in Nitrogen Cycling in Agricultural Ecosystems Kumulative Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften an der Fakultät für Biologie der Ludwig-Maximilians-Universität München vorgelegt von Brigitte Hai aus Landshut Dezember 2009   Dissertation eingereicht am 01.12.2009 1. Gutachter: Prof. Dr. Anton Hartmann 2. Prof. Dr. Jörg Overmann Mündliche Prüfung am 09.03.2010 Abstract The investigation of biochemical cycles in different environmental habitats is becoming more and more vital to improve and sustain the productivity as climate change and management practices drastically change speed, intensity and balance of nutrient cycling. The conversion of nitrogenous compounds in terrestrial ecosystems, mainly mediated by microorganisms, is regarded as a central turnover process in ecology, as nitrogen is one of the limiting factors for plant growth. The different processes of the nitrogen cycle are controlled by several biotic and abiotic factors. The adaptation mechanisms of functional microbial groups in response to governing factors, however, are still poorly understood.