The Invasive Species Initiative
Biological invasions are a serious threat to ecosystems and species across the world as well as to human development, human health and livelihoods. This driver of ecosystem degradation has been recognized by IUCN for more than a decade and is the subject of a number of policy statements and recommendations of IUCN’s governing body, the World Conservation Congress.

The Invasive Species Initiative is part of the Global Species Programme of IUCN, located in the Eastern and Southern Africa Regional Office in Nairobi, Kenya.

In 2000, IUCN, through its Invasive Species Specialist Group of the Species Survival Commission, produced a pivotal document IUCN Guidelines for the prevention of biodiversity loss caused by alien invasive species and followed this with 100 of the World’s Worst Invasive Species the same year which has now been published in more than five languages (

IUCN had already been a partner in the Global Invasive Species Programme (GISP) since its inception in 1997. The Global Invasive Species Initiative was started in 2007 and is operated from the IUCN Eastern and Southern Africa Regional Office in Nairobi, Kenya, with a global mandate to address and advise on issues of invasive species across IUCN programmes, commissions, members and partners, especially the Secretariat of the Convention on Biological Diversity.

Recent and current activities
One of the invasive species initiative projects ‘Removing Barriers to Invasive Plant Management in Africa’ was finalized in July 2010. It covered four countries: Zambia, Ghana, Ethiopia and Uganda and had been involved in developing capacity and information for the prevention and management of invasive plants in Africa. The project was funded by the Global Environment Facility (GEF) through UNEP and technically supported by IUCN and CABI-Africa.

So much information was brought to light and at the end of the project the message was clear: this is a problem that we cannot afford to ignore. Surveys were carried out within the four countries to create a database with information on invasive species present, their locations, extent and impacts. This showed that both natural and man-made ecosystems are being damaged at unprecedented rates.

The alien species of the shrub Lantana camara was found to be present and invasive in all four countries. In Uganda, Lantana camara invasions covered vast areas of the country, one particularly bad invasion was detected near Hima in Western Uganda. The allelopathic capacity (the inhibition of growth in one species of plants by chemicals produced by another species) of Lantana should not be underestimated. It is capable of preventing all other plants from growing under and near it and forms single-species stands that exclude all other plants and any land uses. Lantana camara seemed to invade more land each year, affecting productive areas and areas within settlements and towns in much greater density than previously noted. This must be described as a serious invader and ‘transformer’ species which deserves immediate attention through assessment and then integrated control involving biocontrol as well as mechanical and chemical methods.

Another serious weed was detected in Uganda by the project team. Parthenium hysterophorus was spreading fast and there was a need to act quickly. Both Lantana and Parthenium were invading the Queen Elizabeth National Park in Western Uganda, endangering populations of animals and native plant species. This was a good chance to demonstrate the importance of having an Early Detection and Rapid Response (ED/RR) system in place. The team swiftly moved into action and awareness was raised in the town of Bushenyi where Parthenium was detected. With the help of the community, the town was cleared of the weed and even florists who had been using it in bouquets cooperated in the eradication.

In Ethiopia, the Parthenium problem is pernicious. It has invaded large areas of agricultural land and farmers are abandoning their land as they cannot clear it. Parthenium hysterophorus has also covered pastoral land in the Borana region of Yabelo. Herbicides used by farmers are not effective and when they weed Parthenium out they develop skin and respiratory allergies. Wetlands like Lake Awassa have not been spared the problem and two national parks, Nechsar (near Arba Minch) and Mago (near Jinka) have both been invaded by Parthenium. This invasive herb has since been detected and is spreading in Kenya and Tanzania and is well established in Mozambique and South Africa.

Mimosa diplotricha, an alien species of spiny, scrambling shrub or vine was detected in Ethiopia where it has become invasive. It was found along roads, on the sides of rocky outcrops and road excavations, in damp areas along the Baro river, fields, farms, forests and coffee plantations—almost everywhere. It was clearly associated with road-making, the spread of soils and the movement of heavy, earth-moving equipment. This is a serious and spreading invasion of a plant that is considered extremely damaging in India, several Indian Ocean island states and Australia and which needs urgent attention. It is currently spreading in Burundi and may be invasive elsewhere in the region.

The situation is grave. The ‘Barrier’s’ project raised public and political awareness on the economic importance of invasive plants – but the same is true of animals and micro-organisms. Training was given in each of the countries to officials, quarantine officers, community members and other groups affected by invasive species which covered identification, ED/RR systems, impacts and management. However, the challenges preventing us from an invasive-free Africa are lack of information and awareness on invasive species issues, human capacity to manage them and financial constraints.

The Invasive Species Initiative also works in other countries of Eastern and Southern Africa as well as the rest of continental Africa and the island states. It has also recently had activities in South America, South-East Asia and the Arabian Peninsula – building capacity to recognise and manage biological invasions and to monitor areas of precious biodiversity for their appearance so that local authorities can move fast to address threats to ecosystem integrity and livelihood support.

A regional project is also being carried out to survey and then prepare an invasive species monitoring plan for the waters ad wetlands of Lake Tanganyika (in Burundi, DRC, Tanzania and Zambia). This UNDP-GEF supported project has brought to light a number of riparian plants that are becoming invasive as well as the serious threat of alien (and potentially invasive) fish species being used in aquaculture near the lake and, more dangerously, in cages within the body of the lake. At present the approach is one of monitoring and then developing strategies to reduce the risks of invasions – especially that may affect the hundreds of endemic fish, molluscs and crustaceans in the lake.

For more information, please contact:

Dr Geoffrey Howard, IUCN's Global Invasive Species Coordinator, email: