A cost-benefit analysis of clearing invasive alien plants in the Berg River quaternary catchment of South Africa

Abstract

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 study 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, under three scenarios using a system dynamics modelling approach. The study shows that, if the production of VAPs commenced in 2015, the net present value (NPV) under all scenarios (namely clearing activities paid for by the government alone, clearing activities with 20% co-financed by the private sector, or the do-nothing scenario) resulted in negative values. If, however, the production of VAPs had commenced from the beginning of the model simulation (2008), the cumulative NPV for both the government-funded clearing activities scenario and the 20% private sector co-finance scenario is strongly positive (higher than ZAR200 million).