Modeling the potential ecological niches of noxious kongwa weed in Tanzania for improved land use management

Noxious weeds are problematic in many parts of the world, greatly affecting areas of agriculture, forests, nature reserves, parks and other open spaces. Astripomoea hyoscyamoides also known as noxious Kongwa weed is a serious problem in agriculture sector particularly in Kongwa district. In order to manage the weed, the first step is identification of the potential habitats. Modelling is one of the best techniques in identifying weed’s potential habitats because it can map large area with less time, less labor and less cost than other weed mapping techniques. The need for modelling the potential ecological niches of this weed has arisen in response to the increasing habitats of the weed in other places apart from its original locality of Kongwa district. Under present climate scenarios, model results showed that semi-arid lands of Tanzania are the most suitable habitats for the weed whereby the highly suitable habitats were found to be in Dodoma, Singida and Manyara regions. Moderately suitable habitats were found in Arusha and Lindi regions and some parts of Tanga, Kilimanjaro, Mtwara, Njombe, Mbeya, Rukwa, Ruvuma and Morogoro regions. Under future climate scenarios, Kongwa weed is predicted to be heading to the Lake zone part of Tanzania around Lake Victoria. The new regions which are likely to be invaded by the Kongwa weed in the future were found to be; Mara, Simiyu, Shinyanga and some parts of Kagera region. In determining the risk posed by different pathways in spreading the weed. Results showed that livestock movements and transportation of fodder posed the greatest risk in spreading the weed. The findings from this study have shown that Kongwa weed can establish itself in many parts of the country and therefore there is a need for coordinated efforts from both government, research institutions and the general public to consolidate plans to manage the weed such as controlled and monitored movement of livestock, transportation of agricultural produce and inputs.

Tanzania Meteorological Authority (TMA)