Impact of climate change and stocking rates on pasture systems in SE Morocco [Elektronische Ressource] : an application of the SAVANNA ecosystem model / vorgelegt von Andreas Roth

Impact of climate change and stocking rates on pasture systems in SE Morocco – An Application of the SAVANNA Ecosystem Model Dissertation zur Erlangung des Doktorgrades (Dr. rer. nat.) der Mathematisch-Naturwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn vorgelegt von Andreas Roth aus Hannover Bonn, im Dezember 2009 Angefertigt mit Genehmigung der Mathematisch-Naturwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn Erscheinungsjahr 2010 1. Gutachter: Prof. Dr. H. Goldbach 2. Gutachter: Prof. Dr. B. Diekkrüger Tag der Promotion: 23. April 2010 For my wife Therese and in loving memory for my mother Summary Extensive sheep and goat grazing provides the main income for population in Morocco’s semi-arid to arid areas where rainfall does not permit cropping without irrigation. As processes of vegetation dynamics cannot be assessed via short-term approaches, modelling grazing and biomass productivity may provide better information for planning the sustainable use of these ecosystems. Southern Morocco has faced decreasing annual rainfall over the last two decades, with a strong impact on the sustainability of the regional ecosystems. Increasing herd sizes as a strategy to offset climate-induced variabilities in animal forage leads to an even more enhanced degradation.