Pedodiversity of southern African drylands Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften im Department Geowissenschaften der Universität Hamburg vorgelegt von Andreas Petersen aus Schmalenfelde Hamburg 2008 Als Dissertation angenommen vom Department für Geowissenschaften der Universität Hamburg Auf Grund der Gutachten von Prof. Dr. Günter Miehlich Prof. Dr. Eva Maria Pfeiffer Prof. Dr. Gabriele Broll Hamburg, den 18.6.2008 Prof. Dr. Kay-Christian Emeis Leiter des Departments für Geowissenschaften Content I. Content II. Abbreviations and acronyms III. List of figures IV. List of tables I Content 1 THEMATIC BACKGROUND AND GENERAL AIMS ................................................. 1 1.1 BIODIVERSITY, GLOBAL CHANGE AND ITS UNDERSTANDING..................................................... 2 1.2 THE BIOTA SOUTHERN AFRICA PROJECT.................................................................................. 7 1.3 AIMS OF THIS STUDY .................................................................................................................. 9 2 METHODS APPLIED....................................................................................................... 13 2.1 SAMPLING SCHEME....................................................................................................................13 2.1.1 Overview of sampling strategies in landscape ecology....................................................14 2.1.2 Development of the sampling procedure in the BIOTA project........................................18 2.2 SOIL RELATED FIELD WORK.......................................................................................................23 2.3 LABORATORY ANALYSES ..........................................................................................................25 2.4 DATA PROCESSING ....................................................................................................................28 2.4.1 Laboratory........................................................................................................................28 2.4.2 Satellite data, aerial photographs and digital elevation models (DEM)..........................30 2.5 SOIL CLASSIFICATION................................................................................................................31 3 SOIL INVENTORY AND SOIL VARIABILITY ON STUDIED AREAS .................. 33 3.1 OBSERVATORY 01 (MILE 46) & 02 (MUTOMPO).......................................................................37 3.1.1 Regional overview ............................................................................................................37 3.1.2 Observatory description ...................................................................................................38 3.1.3 Soils ..................................................................................................................................39 3.1.3.1 Main soil units........................................................................................................................... 39 3.1.3.2 Remarks on classification.......................................................................................................... 41 3.1.3.3 Description of reference profiles............................................................................................... 42 3.1.3.4 Discussion of soil properties ..................................................................................................... 46 I Content 3.2 OBSERVATORY 03 (SONOP).......................................................................................................49 3.2.1 Regional overview ............................................................................................................49 3.2.2 Observatory description ...................................................................................................50 3.2.3 Soils ..................................................................................................................................52 3.2.3.1 Main soil units........................................................................................................................... 52 3.2.3.2 Remarks on classification.......................................................................................................... 54 3.2.3.3 Description of reference profiles............................................................................................... 55 3.2.3.4 Discussion of soil properties ..................................................................................................... 58 3.3 OBSERVATORY 04 OMATAKO (TOGGEKRY)..............................................................................63 3.3.1 Regional overview ............................................................................................................63 3.3.2 Observatory description ...................................................................................................65 3.3.3 Soils ..................................................................................................................................66 3.3.3.1 Main soil units........................................................................................................................... 66 3.3.3.2 Remarks on classification.......................................................................................................... 67 3.3.3.3 Description of selected reference profiles ................................................................................. 68 3.3.3.4 Discussion of soil properties ..................................................................................................... 75 3.4 OBSERVATORY 05 (ERICHSFELDE / OTJIAMONGOMBE)............................................................81 3.4.1 Regional overview ............................................................................................................81 3.4.2 Observatory description ...................................................................................................81 3.4.3 Soils ..................................................................................................................................82 3.4.3.1 Main soil units........................................................................................................................... 82 3.4.3.2 Remarks on classification.......................................................................................................... 84 3.4.3.3 Description of selected reference profiles ................................................................................. 85 3.4.3.4 Discussion of soil properties ..................................................................................................... 91 3.5 OBSERVATORY 06 (OKAMBORO) ..............................................................................................95 3.5.1 Regional overview ............................................................................................................95 3.5.2 Observatory description ...................................................................................................95 3.5.3 Soils ..................................................................................................................................96 3.5.3.1 Main soil units........................................................................................................................... 96 3.5.3.2 Remarks on classification.......................................................................................................... 98 3.5.3.3 Description of selected reference profiles ................................................................................. 99 3.5.3.4 Discussion of soil properties ................................................................................................... 102 3.6 OBSERVATORIES 39 (NAREIS) AND 40 (DURUCHAUS) ............................................................104 3.6.1 Regional overview ..........................................................................................................104 3.6.2 Observatory description .................................................................................................104 3.6.3 Soils ................................................................................................................................106 3.6.3.1 Main soil units......................................................................................................................... 106 3.6.3.2 Remarks on classification........................................................................................................ 108 3.6.3.3 Description of selected reference profiles ............................................................................... 109 3.6.3.4 Discussion of soil properties ................................................................................................... 113 II Content 3.7 OBSERVATORIES 10 (GELLAP OST) AND 11 (NABAOS)...........................................................117 3.7.1 Regional overview ..........................................................................................................117 3.7.2 Observatory description .................................................................................................117 3.7.3 Soils ................................................................................................................................118 3.7.3.1