An assessment of 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

Abstract

Acacia saligna (Port Jackson) is one of the most pervasive IAPs in South Africa. The government’s control efforts have by and large not been co-financed by the private sector due to a lack of incentives. Here we develop a system dynamics model to assess the costs and benefits of using the invasive Acacia saligna for the production of wood polymer composites (WPCs). The cumulative net present value for clearing Acacia saligna and making WPCs amounts to approximately ZAR122.1 million for the baseline scenario (no WPC production), and is estimated to be ZAR144.4 million for Scenario 2 (WPC production with 20% co-financing), ZAR172.7 million for Scenario 3 (50% co-financing) and ZAR211.2 million for Scenario 4 (100% co-financing). In addition to these direct financial benefits, the control of Acacia saligna also offers benefits with respect to employment, an increase in the state’s tax revenue base, and an increase in the contribution to GDP.