Fakultt Umweltwissenschaften Limnological aspects of the Uvs Nuur Basin in northwest Mongolia Dissertation zur Erlangung des akademischen Grades Doctor rerum naturalium (Dr. rer. nat.) vorgelegt von Dipl.-Biol. Markus Paul geb. 14.03.1968 Gutachter: Herr Prof. Dr. Dietrich Borchardt Technische Universitt Dresden Frau Prof. Dr. Brigitte Nixdorf Brandenburgische Technische Universitt Cottbus Dresden, 12. November 2012 Erklrung des Promovenden Die bereinstimmung dieses Exemplars mit dem Original der Dissertation zum Thema: „Limnological aspects of the Uvs Nuur Basin in northwest Mongolia“ wird hiermit besttigt. Dresden, 12.11.2012 Ort, Datum ……………………………………….…. Unterschrift (Vorname Name) 2 Limnological aspects of the Uvs Nuur Basin in northwest Mongolia Dissertation zur Erlangung des akademischen Grades doctor rerum naturalium (Dr. rer. nat.) an der Fakultät Umweltwissenschaften der Technischen Universität Dresden vorgelegt von Diplombiologe Markus Paul Dresden, 12. November 2012 Gutachter: Prof. Dr. Dietrich Borchardt Prof. Dr. Brigitte Nixdorf This work was funded by Deutsche Forschungsgemeinschaft (DFG; grants UH 54/2-1, HO 1778/1-2 and HO 1778/1-3) and Gesellschaft für Technische Zusammenarbeit (GTZ; contract No. 81011694), which is gratefully acknowledged. Table of Contents Acknowledgments.........................................................................................................................................................ii Abstract..........................................................................................................................................................................iii List of Tables.................................................................................................................................................................iii List of Figures ...............................................................................................................................................................vi 1 Introduction............................................................................................................................................................1 1.1 Significance of the investigations..............................................................................................................1 1.2 Aims of the investigations..........................................................................................................................2 1.3 Sequence of field research activities .........................................................................................................3 1.4 Area of investigation ...................................................................................................................................4 1.4.1 Topographic situation and morphology ......................................................................................4 1.4.2 Climate ..............................................................................................................................................5 1.4.3 Geology and soils ............................................................................................................................9 1.4.4 Vegetation.......................................................................................................................................10 1.4.5 Population and economy .............................................................................................................10 1.4.6 Former limnological investigations in the Uvs Nuur Basin ...................................................11 1.4.7 Short description of the investigated waters.............................................................................12 2 Methods.................................................................................................................................................................15 2.1 Sampling......................................................................................................................................................15 2.2 Field measurements...................................................................................................................................16 2.3 Laboratory analyses and data evaluation................................................................................................19 3 Results and discussion.........................................................................................................................................26 3.1 Rivers...........................................................................................................................................................26 3.1.1 Morphology and hydrology .........................................................................................................26 3.1.2 Runoff dynamics............................................................................................................................34 3.1.3 Water temperature and freezing..................................................................................................38 3.1.4 Chemical properties ......................................................................................................................39 3.1.5 Aquatic biota ..................................................................................................................................43 3.2 Lakes............................................................................................................................................................53 3.2.1 Formation and morphometry......................................................................................................53 3.2.2 Water level changes and water balance......................................................................................58 3.2.3 Temperature and overturn dynamics of the water body.........................................................63 3.2.4 Vertical gradients of physico-chemical parameters and chlorophyll.....................................65 3.2.5 Horizontal gradients in Uvs Nuur: surface temperature and suspended matter.................69 3.2.6 Salinity and ionic composition ....................................................................................................71 3.2.7 Nutrients and trophic state..........................................................................................................74 3.2.8 Sediments........................................................................................................................................79 3.2.9 Aquatic biota ..................................................................................................................................83 3.3 Groundwater ..............................................................................................................................................95 3.3.1 Hydrology.......................................................................................................................................95 3.3.2 Chemical composition..................................................................................................................96 3.3.3 Biota.................................................................................................................................................98 4 Conclusions and synthesis..................................................................................................................................99 4.1 Exogenous factors influencing the character of water bodies ...........................................................99 4.1.1 Biological structure of running waters.....................................................................................100 4.1.2 Biological structure of lakes.......................................................................................................104 4.2 Food webs.................................................................................................................................................105 4.3 Biogeographical classification................................................................................................................110 i 4.4 Spatial sequence of water bodies and material flows.........................................................................113 4.5 Transformation of the water bodies.....................................................................................................116 4.6 Typology of water bodies.......................................................................................................................117 4.7 Protection of landscape and waters......................................................................................................121 5 Literature .............................................................................................................................................................124 6 Appendices..........................................................................................................................................................140 6.1 Tables.........................................................................................................................................................140 6.2 Cross sections and longitudinal profiles of rivers ..............................................................................169 6.3 Microscopical images of algal species...................................................................................................175