Page 35 - State of Biodiversity Report 2022/2023

4.5. Threats to Biodiversity in Durban
Some of the major threats to biodiversity include:
u Transformation of natural areas (habitat destruction,
degradation and fragmentation)
u Introduction and the spread of invasive alien species u Over-exploitation (e.g. harvesting and illegal mining) u Pollution and diseases
u 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.
Concerns on urban environmental quality, increasing knowledge on impacts of climate change and pursuit for sustainable development have increased the need for past, current and future knowledge on the transformation of natural areas. The results (Otunga, 2014) show a consistent pattern of decline in land use and land cover types associated with green spaces. This is further supported by Table 5 that shows the change in vegetation type cover with those highlighted in red being so transformed that set conservation targets cannot be met due to the fact that areas remaining is higher that what the conservation target is for that vegetation type.
STATE OF BIODIVERSITY REPORT 2022/2023 33