Ecological analysis of Afromontane grasslands in the Eastern Free State using the biotope quality index
Loading...
Date
2023
Authors
Modise, Serero Abiot
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
Environmental disturbance poses threats to conservation efforts in highland montane grassland in temperate regions prone to land transformation, overgrazing, habitat fragmentation, soil erosion, uncontrolled fires and plant invasion. In this study, the Biotope Quality Index (𝘉𝘘𝘐) was adopted and applied as a species surrogate to evaluate impact of disturbance on the Afromontane grassland vegetation types namely Sandy Eastern Free State, Basotho Montane Shrubland and North Drakensberg Highlands Drakensberg Grasslands in the Golden Gate Highlands National Park. In addition, the Biotope Conservation Status (𝘉𝘊𝘚) was developed as an additional to 𝘉𝘘𝘐 to indicate the impact of environmental disturbance on conservation efforts in protected areas. Chapter 1 begins with a brief history that highlights the importance of temperate grasslands and the role that protected areas play in the conservation of sensitive biomes. In Chapter 2, the most regularly used environmental quality indices, their application domain (air, water and terrestrial), arithmetic formulation, development and application process as well as suggestions into continuous usage and nomenclature of those environmental indices were reviewed. Chapter 3 indicates how the 𝘉𝘘𝘐 was adopted into the 𝘉𝘘𝘐veg for vegetation ecology analysis, using three common plant species abundance-cover scales (Domin, Braun-Blanquet and percentage density), and results suggested that, for 𝘉𝘘𝘐, species list must include most plants present in the vegetation type to allow variation within data points. Furthermore, 𝘉𝘘𝘐veg was able to indicate variation in sites which were affected by relatively high degree of soil erosion, plant invasion / encroachment and long-term effects of historical agricultural practices. Moreover, the application of the 𝘉𝘘𝘐 as a species surrogate was demonstrated, with inclusion of the 𝘉𝘊𝘚 add-on as well as a ArcGIS Feature Analysis parameter, to illustrate the conservation status of the Sandy Eastern Free State in Chapter 4 and the Basotho Montane Shrubland grassland vegetation type in Chapter 5 using arthropod assemblages to evaluate as a unit of measure. Furthermore, the inclusion of the 𝘉𝘘𝘐 as a species surrogate for rapid bioassessments and biomonitoring was supported using both plant communities and arthropod assemblages to highlight the impact of environmental disturbances in the Highlands Drakensberg Grassland vegetation unit in Chapter 6. In conclusion, 𝘉𝘘𝘐 indicated the ability to use plants as a unit of measure and its flexibility for common vegetation abundance-cover scales. Again, 𝘉𝘘𝘐 was able to highlight the impacts of environmental disturbances on plant communities and arthropod assemblages. Therefore, it is recommended that 𝘉𝘘𝘐 and 𝘉𝘊𝘚 be used as a surrogate for bioassessment and biomonitoring to assess impacts of disturbance toward and to indicate the conservation status of important ecosystems, bioregions, or biotopes.
Description
Thesis (Ph.D. (Entomology))--University of the Free State, 2023
Keywords
Biomonitoring, biotope conservation status, biotic communities, environmental disturbance, highveld grassland bioregion, species surrogate