Page 21 - State of Biodiversity 2019-2020

4.5. Threats to Biodiversity in Durban
Some of the major threats to biodiversity include:
• Transformation of natural areas (habitat destruction, degradation and fragmentation)
• Introduction of invasive alien species
• Over-exploitation (e.g. harvesting and illegal and
mining)
• Pollution and diseases
• Human-induced climate change
Due to the lack of quantitative data relating to many of these threats, this report will only focus on transformation, invasive alien species and climate change. More information will be included as it becomes available.
Land transformation involves the changing of land cover from natural vegetation to several forms of human utilisation; for example: the removal of grassland area and its replacement with agricultural activities. This example is fairly common within the eThekwini context as sugarcane has become one of the most important
agricultural activities within the municipal area and has resulted in the extensive loss of grasslands. Other forms of transformation include degradation, which is a decrease in the health and functioning of a natural system oftentimes as a result of surrounding human pressures. Lastly, fragmentation is the splitting up of large vegetation types into smaller ones from human developments such as roads and housing. This separation limits the movement of biodiversity within the vegetation type and slowly degrades its health. All these types of shifts from natural vegetation into transformed land result in irreversible change with loss of habitat, species, genetic variability and connectivity all being removed. This ultimately impacts on and reduces the effectiveness and range of environmental goods and services, which these areas could provide to both humans and other natural systems. Many of these services, such as the supply of water and food, have a direct impact on people’s lives and as these habitats are degraded, these services diminish.
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