Impact of Mineral Exploration on Ecosystem Characters and Mallee Vegetation of Pinkawillinie Conservation Park, South Australia Lindy A. Scott Submitted for the degree of Doctor of Philosophy School of Earth and Environmental Sciences The University of Adelaide March 2011 § § Table of Contents Table of Contents Table of Contents.............................................................................................................................................i Index of Figures and Tables............................................................. .............................................................. vi Abstract.................................................................................. ...................................................................... ixi Declaration............................................................................. ..................................................................... xiii Acknowledgements............................................................... .................................................................... xiiiv Chapter 1 Introduction.......................................................... ........................................................................ 1 a) Natural disturbance ................................................................................................................................... 4 b) Human induced disturbance ...................................................................................................................... 5 c) Introduced plants and animals .................................................................................................................... 6 d) Factors affecting ecosystems ...................................................................................................................... 6 Chapter 2 Description of the system............................................... ................................................... ..........11 2.1 General description .......................................................................................................................... 11 2.2 Geology and Soil ............................................................................................................................... 11 2.3 Climate ............................................................................................................................................ 12 2.4 Vegetation of Pinkawillinie CP ........................................................................................................... 14 2.5 The value of mineral exploration in the area ...................................................................................... 15 2.6 Conservation status of the study area ................................................................................................ 20 Chapter 3 Effects of disturbance on the landscape and ecosystem processes - Physical characters ............... 21 Introduction ................................................................................................................................................ 21 Methods ..................................................................................................................................................... 24 3.1 Soil colour and Texture ..................................................................................................................... 25 3.2 Compaction ...................................................................................................................................... 25 3.3 Bulk density ...................................................................................................................................... 26 3.4 Soil water content ............................................................................................................................ 26 3.4.1 Soil Samples ............................................................................................................................. 26 3.4.2 Moisture readers ...................................................................................................................... 27 3.5 Soil erosion ...................................................................................................................................... 28 Statistical Analyses ...................................................................................................................................... 28 Results ........................................................................................................................................................ 31 3.1 Soil Colour and Texture ..................................................................................................................... 31 3.2 Compaction ...................................................................................................................................... 32 3.3 Bulk density ...................................................................................................................................... 40 3.4 Soil water content ............................................................................................................................ 40 3.4.1 Soil Samples ............................................................................................................................. 40 3.4.2 Moisture readers ...................................................................................................................... 42 3.5 Erosion ............................................................................................................................................. 46 Discussion ................................................................................................................................................... 47 Chapter 4 Effects of disturbance on the landscape and ecosystem processes- Spatial heterogeneity in nutrient distribution.............................................................. ...................................................................... 56 Introduction ................................................................................................................................................ 56 Methods ..................................................................................................................................................... 60 i Table of Contents 4.1 Total Nitrogen, Phosphorus and Potassium ........................................................................................ 60 4.2 pH, Conductivity ............................................................................................................................... 60 4.3 Litter ................................................................................................................................................ 60 4.4 Total Carbon ..................................................................................................................................... 61 Statistical Analyses ...................................................................................................................................... 61 Results ........................................................................................................................................................ 62 4.1 Total Nitrogen, Phosphorus and Potassium ........................................................................................ 62 4.2 pH, Conductivity ............................................................................................................................... 64 4.3 Litter ................................................................................................................................................ 65 4.4 Total Carbon ..................................................................................................................................... 66 Discussion ................................................................................................................................................... 66 Chapter 5 Emergence studies on the soil seedbank in disturbed and undisturbed areas ............................... 71 Introduction ................................................................................................................................................ 71 Methods ..................................................................................................................................................... 74 5.1 Emergence from the soil seedbank .................................................................................................... 74 5.2 Potential contributors to the soil seedbank ........................................................................................ 75 5.3 Seed removal experiments ................................................................................................................ 76 Statistical Analyses ...................................................................................................................................... 76 Results ........................................................................................................................................................ 78 5.1 Emergence from the soil seedbank .................................................................................................... 78 5.2 Potential Contributors to