A Plant Ecological Study and Management Plan for Mogale's Gate Biodiversity Centre, Gauteng
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A PLANT ECOLOGICAL STUDY AND MANAGEMENT PLAN FOR MOGALE’S GATE BIODIVERSITY CENTRE, GAUTENG By Alistair Sean Tuckett submitted in accordance with the requirements for the degree of MASTER OF SCIENCE in the subject ENVIRONMENTAL MANAGEMENT at the UNIVERSITY OF SOUTH AFRICA SUPERVISOR: PROF. L.R. BROWN DECEMBER 2013 “Like winds and sunsets, wild things were taken for granted until progress began to do away with them. Now we face the question whether a still higher 'standard of living' is worth its cost in things natural, wild and free. For us of the minority, the opportunity to see geese is more important that television.” Aldo Leopold 2 Abstract The Mogale’s Gate Biodiversity Centre is a 3 060 ha reserve located within the Gauteng province. The area comprises grassland with woodland patches in valleys and lower-lying areas. To develop a scientifically based management plan a detailed vegetation study was undertaken to identify and describe the different ecosystems present. From a TWINSPAN classification twelve plant communities, which can be grouped into nine major communities, were identified. A classification and description of the plant communities, as well as, a management plan are presented. The area comprises 80% grassland and 20% woodland with 109 different plant families. The centre has a grazing capacity of 5.7 ha/LSU with a moderate to good veld condition. From the results of this study it is clear that the area makes a significant contribution towards carbon storage with a total of 0.520 tC/ha/yr stored in all the plant communities. KEYWORDS Mogale’s Gate Biodiversity Centre, Braun-Blanquet, TWINSPAN, JUICE, GRAZE, floristic composition, carbon storage 3 Declaration I, Alistair Sean Tuckett, declare that “A PLANT ECOLOGICAL STUDY AND MANAGEMENT PLAN FOR MOGALE’S GATE BIODIVERSITY CENTRE, GAUTENG” is my own work and that all sources that I have used or quoted have been indicated and acknowledged by means of complete references. Signature Date (Mr A.S. Tuckett) 4 Table of Contents Chapter 1 Introduction ...................................................................................................... 14 Biodiversity and Human Influences .................................................................................. 14 Significance of Vegetation Studies .................................................................................. 15 Vegetation of Gauteng ..................................................................................................... 16 Impact of Climate Change on Vegetation ........................................................................ 17 Conservation on Mogale’s Gate Biodiversity Centre ........................................................ 18 Problem Statement and Objectives ................................................................................. 19 References ...................................................................................................................... 20 Chapter 2 Study Area ........................................................................................................ 25 Location ........................................................................................................................... 25 Geology ........................................................................................................................... 26 Soil .................................................................................................................................. 27 Land Types ..................................................................................................................... 28 Climate ............................................................................................................................ 31 Vegetation ....................................................................................................................... 33 Water Resources ............................................................................................................. 35 Fauna of Mogale’s Gate Biodiversity Centre .................................................................... 35 Uses ................................................................................................................................ 36 References ...................................................................................................................... 37 Chapter 3 Vegetation classification and description ...................................................... 39 Introduction ..................................................................................................................... 39 Materials and Methods .................................................................................................... 40 Sampling ...................................................................................................................... 40 Vegetation Mapping and Habitat Description ............................................................ 40 Data analysis ............................................................................................................... 41 Vegetation Mapping and Habitat Description ............................................................ 41 Results ............................................................................................................................ 41 Classification of Plant Communities ............................................................................. 41 Description of Plant Communities ................................................................................ 42 1. Schoenoplectus corymbosus-Typha capensis Wetland ....................................... 43 2. Hemarthria altissima-Arundinella nepalensis Wetland ......................................... 44 3. Euclea crispa subsp. crispa-Olea europea subsp. africana Woodland ................ 45 3.1 Euclea crispa subsp. crispa-Olea europea subsp. africana-Setaria megaphylla Woodland ................................................................................ 46 3.2 Euclea crispa subsp. crispa-Olea europea subsp. africana-Acacia caffra Woodland ................................................................................................... 47 4. Senecio inornatus-Hyparrhenia tamba Grassland ............................................... 49 5. Sporobolus africanus-Hyparrhenia hirta Grassland ............................................. 50 5.1 Sporobolus africanus-Hyparrhenia hirta-Eucalyptus camaldulensis Woodland ................................................................................................... 51 5.2 Sporobolus africanus-Hyparrhenia hirta-Cynodon dactylon Grassland ....... 52 5.3 Sporobolus africanus-Hyparrhenia hirta-Senecio isatideus Grassland ....... 54 6. Seriphium plumosum-Alloteropsis semialata subsp. eckloniana Grassland ......... 55 7. Setaria sphacelata var. sphacelata-Themeda triandra Grassland ....................... 57 8. Protea caffra subsp. caffra-Melinis nerviglumis Woodland .................................. 58 5 9. Xerophyta retinervis-Loudetia simplex Grassland ............................................... 60 Discussion and Conclusion .............................................................................................. 61 Savanna Communities ................................................................................................. 61 Grassland Communities ............................................................................................... 62 References ...................................................................................................................... 64 Chapter 4 Floristic Analysis of Mogale’s Gate Biodiversity Centre .............................. 67 Introduction ..................................................................................................................... 67 Methods .......................................................................................................................... 67 Results ............................................................................................................................ 68 Discussion & Conclusion ................................................................................................. 73 References ...................................................................................................................... 77 Chapter 5 Veld Condition and Grazing Capacity ............................................................ 80 Introduction ..................................................................................................................... 80 Materials and Methods .................................................................................................... 81 Results ............................................................................................................................ 82 Discussion ....................................................................................................................... 84 1. Schoenoplectus corymbosus-Typha capensis Wetland ............................................ 84 2. Hemarthria altissima-Arundinella nepalensis Wetland .............................................. 84 3.1. Euclea crispa subsp. crispa-Olea europea subsp. africana-Setaria megaphylla Woodland ............................................................................................................ 84 3.2. Euclea crispa subsp. crispa-Olea europea subsp. africana-Acacia