Findings from two recent papers by C·I·B postdoc, Ross Shackleton, highlight how the invasive plants prickly
pear (Opuntia stricta) and Lantana (Lantana camara), cause negative impacts on local communities and the environment in
Kenya and Uganda.
Prickly pear and Lantana were introduced as ornamental plants, but have become widespread invasive species in eastern
Africa. Prickly pear is common in arid and semi-arid areas, where as Lantana is common in wetter areas. Together they cover much of the
Findings highlight that these two invasive plants have a number of negative impacts on people and the environment which in
turn have a negative impact on the local community’s well-being. Both species have negative effects on the native plant communities which
reduce biodiversity, grazing potential and the collection of important plants such as those used for traditional medicine. Both species also
have negative effects on livestock production and health. Compounds in Lantana are poisonous and can cause animal sickness and death. The
spines of prickly pears cause irritation and infection, which can lead to death of animals.
Almost half (48%) of people in Kenya are affected, losing between US$500 and US$1000 worth of livestock due to prickly pear
invasions. Lantana also invades croplands and can reduced maize yields by 25-50% for around a third of households. Lantana also encroaches
lands and makes them unusable and in some cases forces local communities to relocate elsewhere.
These impacts are mirrored in a quote from a villager in Uganda “I am a victim of Lantana in many ways. I used to
live in Kagonji village years back but I had to find land here, and relocate my family because my previous land was totally covered in
Lantana. We had no farmland, grazing land or space for my grandchildren to play. I even feel ashamed telling people that I ran away because
“The negative effects of invasive plants are well recognised for biodiversity and there is now an increasing
literature base on how invasive plants also have negative effects for local communities and their livelihoods” said Ross
Shackleton. “This information is important as it can be used as evidence to raise funding to aid management in the future.”
Read the papers
Ross T. Shackleton, Arne B. R. Witt, Francis M. Piroris, Brian W. van Wilgen (2017). Distribution and socio-ecological
impacts of the invasive alien cactus Opuntia stricta in eastern Africa. Biological Invasions.
Ross T Shackleton, Arne BR Witt, Winnifred Aool & Corin F Pratt (2017). Distribution of the invasive alien weed,
Lantana camara, and its ecological and livelihood impacts in eastern Africa. African Journal of Range & Forage Science.
For more information, contact Ross Shackleton at firstname.lastname@example.org
a) Prickly pear (Opuntia stricta); b) prickly pear close up showing fruit and spines; c) baboon scat
full of prickly pear; d and e) prickly pear invasions in rangelands; f) sheep blinded by prickly pear spines; g) biocontrol agents on
prickly pears; h) impacts of biological control agents on prickly pears in the Laikipia County, Kenya. (Photo credit: Arne Witt)
a) Lantana (Lantana camara) flowers and leaves; b) Lantana infestation in Kenya; c and d) Lantana
invasions in Ethiopia; e and f) photosentsitivity in cattle that have ingested Lantana. (Photo credits: Arne Witt,
MD Day, Oueensland Department of Primary Industries)