The spread of invasive plant species has serious consequences for Africa. Toxic weeds and harmful shrubs significantly shrink rangelands and lower the productivity of major grain foods such as maize (in some instances by up to 45%).
Toxic weeds suppress the growth of staple crops and take over fields that could otherwise be used for agriculture. The UN Sustainable Development Goals emphasise the need to better manage land degradation and biodiversity loss and develop strategies to combat poverty.
However, the invasion of rangelands and croplands by harmful non-native species is not specifically mentioned in the UN sustainability framework as a significant and emerging environmental issue. Equally, the AU Commission (AUC) sounds the alarm over rising food insecurity in Africa, but there are no tools or coherent strategies on how to address the challenges posed by invasive species in the context of enhancing food security. This briefing highlights the significance of earth observation (EO) data for the development of tools and strategies to curb the increasing spread of invasive species.
Recommendations:
- amendments to existing and future policy frameworks, such as the CBD and the AUC strategy, are required to emphasise the need to develop more effective and coherent protocols for the management of invasive species
- spatial occurrence maps of invasive species should be used by decision-makers to better understand and manage their effects on cropland and rangeland productivity, and ultimately food security in Africa
- policymakers and decision makers need sound evidence on the local uses and impacts of invasive species in order to become aware of their costs and benefits
- international bodies that promote the use of EO for societal benefit areas (such as GEOSS and UN SPIDER) must include invasive species mapping in their outreach and training agendas. This should be facilitated by country- or region-specific case studies that help to show the potential of EO products to more effectively manage invasive species across borders