Investigation into the dynamics of invasive alien clearing restoration practices in South Africa
In South Africa, restoration success is advocated as a state of ecosystem which maximizes ecosystem benefits by the removal of certain invasive alien plant (IAP) species. A large effort has been made to remove IAPs in South Africa as a means of reducing further degradation as well as minimizing the direct loss of ecosystem goods and services valued at over 100 billion rand per annum. The cost and benefits associated with this type of restoration varies by location, IAP composition and extent of invasion. Many restoration projects clear an area of IAP types and then return for a series of follow up clearing to remove regrowth until seedbanks are depleted. Given this context, the purpose of the development of this short term interactive model is to understand how investment into restoration projects as well as the process of invasive alien plant clearings effects the cost and benefits of restoration clearing over a fixed time frame (5 years). With the help of this model users will be able to simulate changes based on various restoration projects and be provided with some insight into the potential benefits and cost of that specific restoration project.
National scale strategic restoration model
This model allows one to run scenarios for national scale restoration efforts for various types of restoration. It was calibrated to historic Working for Water project data and can be used to provide some indication of likely future restoration trajectories and outcomes. The model is interactive allowing the user to adjust many parameters and evaluate the effect of these simulation outcomes.
The Acacia saligna (Port Jackson) Recycled Thermoplastic Waste-Wood Polymer Composites system dynamics model (PORTTHERM-WPC model)
Biological invasions emanating from IAPs like Acacia saligna, and the environmental impacts caused by thermoplastic waste are characterised by various hidden dynamics and complexities. Moreover, the use of these two environmentally non-benign sources as raw materials for the production of WPCs, and the corresponding environmental, economic and social impacts, are difficult to assess as a result of the numerous complexities and dynamics of the subject matter. This PORTTHERM-WPC interactive model was developed to assess the costs and benefits of using Acacia saligna (Port Jackson) and recycled thermoplastics for the production of wood polymer composites in the Western Cape province, South Africa.
The Prosopis spp. land-use trade-off system dynamics model (PROLAND model)
The invasive Prosopis spp. tree is one of the major causes of disturbance affecting the Orange River water management areas in the Northern Cape, South Africa. These disturbances affect natural capital, such as reducing the stream flow of the Orange River, causing a decline in biodiversity of the native Nama Karoo vegetation, consuming excessive water, and invading dryland areas. This interactive model assessed the economic value of different land-use options following the control of Prosopis spp. to prevent re-invasion in the Orange River water management areas between Onseepkans and Pella in the Northern Cape province of South Africa.
A cost-benefit analysis of clearing invasive alien plants in the Berg River quaternary catchment of South Africa (RESTORBERG model)
Environmental degradation caused by invasive alien plants must be remedied in time before the land becomes too heavily degraded for restoration to be successful. This interactive RESTOREBERG model investigates the cost-benefit analysis of restoring natural capital through clearing invasive alien plants and transforming them into value-added products (VAPs), such as wood chips, timber, firewood, charcoal and briquettes within the Berg River catchment in the Western Cape province of South Africa.
Beaufort West Regional Economic SysTem dynamics mOdel for the Restoration of Ecosystems and project Prioritisation (The RESTORE-P model)
The RESTORE-P model uses a market-based approach to classify and prioritise restoration projects that are subject to budgetary constraints. The model evaluates the effects of restoration on natural capital. While the model was developed for Beaufort West it can be customised to different contexts by changing the parameters of this interactive model.
Mzimvubu catchment system dynamics model for the Ntabelanga and Laleni dams
The Mzimvubu Water Project (MWP) includes the construction of two dams, namely the Ntabelanga and Laleni dams. This development is to expand agricultural activity and kick-start subsequent economic development as the uMzimvubu river catchment is characterised by high levels of poverty, low levels of employment, little economic activity and an increasing reliance of households on social assistance. This interactive model allows changes of key parameters that estimates the lifespans of both the Ntabelanga and Laleni dams.
System dynamics model for clearing invasive alien plants in Zululand
More than 60% of northern Zululand is tribal land with a substantial area falling within protected areas. Much of the land is invaded by invasive alien plant species, most of these species do not have any economic value and compromises communal livelihoods and biodiversity.This interactive model allows changes of key parameters that estimates the benefits and net present values of clearing invasive alien plants in Northern Zululand, South Africa.
