Chromolaena odorata dominating the under-canopy in Central African forests and woodlands.
These alien invasives also act like paraffin in the under-canopy during the hot dry season, increasing the intensity of wildfires that sweep through the African dry seasons.
These and other alien invasives smother the natural under-canopy, including the regeneration of upper canopy species, during the dry season they increase wildfire damage and species deaths. The impact on local communities is often catosphophic with large areas under crops being destroyed by these wildfires, homes and infrasturacture destroyed and reports of injury and deaths annually from these “intensified” wildfires. The spread of these alien invasives into surrounding commercial and subsistence agricultural also increasing farming costs and results in yield reductions. Costs of controlling these alien invasives is often beyond the capacity of local communities and governments in Africa.
Recent research is finally starting to put a cost to there alien invasives and their control. See: Towards estimating the economic cost of invasive alien species to African crop and livestock production | CABI Agriculture and Bioscience | Full Text (biomedcentral.com)
Please also note the correction: