Invasives Blog

CABI has taken part in a two-day workshop of a project funded by the Darwin Initiative which is aimed at tackling the scourge of woody weeds that threatens biodiversity and livelihoods in Tanzania.

Dr René Eschen, based at CABI’s centre in Switzerland, and Winnie Nunda of CABI’s regional centre for Africa in Nairobi participated in the event, during which participants finalised a draft management plan to protect habitats and livelihoods around Lake Natron and Lake Manyara from an invasion of Prosopis juliflora.

East African grasslands, forests and lakesides are home to some of the world’s most iconic megafauna and some of the poorest and marginalised communities. Northern Tanzania’s Tarangire-Manyara ecosystem has a number of iconic and/or protected species including lesser flamingo, blue wildebeest, cheetah and East African sandalwood.

However, these are at risk from the evergreen prosopis – introduced in the 1970s to provide firewood and ‘regreen’ degraded landscapes – which has now invaded over 10 million ha in the lowlands of Ethiopia, Kenya and recently northern Tanzania. The project area has so far experienced little invasion, but communities are aware that the species is spreading with livestock moving from affected neighbouring areas in Kenya.

The project is supporting the implementation of the Tanzanian National Invasive Species Strategy and Action Plan (NISSAP) and engages diverse stakeholders to share in the co-development of a prosopis management strategy for the Lake Natron basin. The process will be documented and was shared with regional stakeholders, so that it can also be implemented across other parts of Tanzania affected by invasive alien plant species.

It is being co-led by CABI and the Tanzania Forestry Research Institute (TAFORI) in partnership with the Tanzania Natural Resource Forum (TNRF), Community Research and Development Services (CORDS), the Tanzania Wildlife Management Authority (TAWA) and the Centre for Development and Environment of the University of Bern (CDE). The project builds on experience and expertise gained through the Woody Weeds and Woody Weeds + projects.

Dr Eschen said, “Prosopis juliflora, known locally as ‘Mrasha,’ requires management at an early stage. This is the most promising and cost-effective strategy to prevent further spread and to preserve the biodiverse and culturally important ecosystem in northern Tanzania.”

Dr John Richard of TAFORI, the co-leader of the project, added that the protection of grasslands and other assets in a landscape that encompasses protected areas used by local communities requires joint decision making and coordinated action by all relevant stakeholders.

A key element of the prosopis strategy for the Lake Natron basin is the prevention of further spread and removal of any prosopis from lightly invaded areas, so as to mitigate any impacts the invasion would have on grasslands, wildlife and livelihoods.

Ms Winnie Nunda said, “The management plan that is being developed could also be adapted for other invasive alien plant species in the region and similar plans can be drawn up for other parts of the country where invasive species threaten protected areas and surrounding communities.”

It was agreed at the workshop that steps would be taken to hold a national conference on prosopis where various stakeholders can meet to discuss how to prevent, detect and control invasive alien plant species in Tanzania.

Participants at the workshop learn more about the spread and management of prosopis in Tanzania (Credit: René Eschen).

District Commissioner of Monduli District, Hon. Joshua Nassari, who addressed the workshop, said the workshop provided an opportunity for members of the Regional Task Force to present their opinions on controlling prosopis to the Office of the Vice President.

“The implementation of the National Invasive Species Strategy and Action Plan will be achieved by strengthening coordination among actors at various levels of decision making,” he said. “This involves them preparing a strategy to control prosopis together, establishing a suitable monitoring system for invasive plants and implementing coordinated joint management.”

He also highlighted how, since the project was launched six months ago, the prosopis problem has already been raised to the district authorities of Monduli, Longido and Ngorongoro.

Consultation meetings have been held in the villages of Wosi Wosi, Pinyinyi and Mto wa Mbu where residents were trained on how to identify and control Mrashia as an initial means of reducing its threats to humans, livestock and wildlife.

Mr Nassari added, “I have been told that this project has been well accepted by our communities, which is a good sign that it will achieve its goal of protecting and reducing the threat to biodiversity and humans while improving people’s lives and preserving the environment.”

He further stressed that a national conference on prosopis will additionally explore not only examine how to mitigate the threats to wildlife habitats but also those to grazing and agricultural land.

“I feel very proud to see that we are moving towards the implementation of the national strategy for the control of invasive plants by starting with the protected areas that were given first priority in the strategy,” Mr Nassari said.

Additional information

Main image: Participants of the three-day workshop aimed at tackling the scourge of woody weeds that threatens biodiversity and livelihoods in northern Tanzania(Credit: Albrecht Ehrensperger).

Project pages

Find out more about the Darwin Initiative project ‘Coordinated invasive plant management to protect Tanzanian biodiversity and livelihoods’ here.

Discover how CABI is helping to tackle prosopis at the Woody Weeds + website and the project page ‘Woody weeds in East Africa.’

Relevant story

‘Study calls for ‘early detection and rapid response’ to stop spread of woody weeds in Eastern Africa.’

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