Distribution of invasive alien Tithonia (Asteraceae) species in eastern and southern Africa and the socioecological impacts of T. diversifolia in Zambia
Date
2019-09-25
Journal Title
Journal ISSN
Volume Title
Publisher
South African National Biodiversity Institute (SANBI)
Abstract
Background: Many alien plant species, such as Tithonia diversifolia, T. rotundifolia and T. tubaeformis, have been introduced to areas outside of their natural distribution range to provide benefits, but have subsequently become invasive, threatening biodiversity and agricultural productivity.
Objectives: The aim of this study was to determine the current distribution and dates of introduction of invasive Tithonia species in eastern and southern Africa and to document the effects of T. diversifolia on rural livelihoods in Zambia.
Method: Roadside surveys, and other sources of information, were used to determine the distribution of invasive Tithonia species in eastern and southern Africa. Household interviews were conducted to gauge perceptions and understand the impacts of T. diversifolia on local livelihoods in Zambia’s Copperbelt province.
Results: Tithonia diversifolia is widespread in Uganda, Kenya, Tanzania, South Africa, Malawi and parts of Zambia but less so in Zimbabwe. Tithonia rotundifolia was comparatively uncommon in eastern Africa but common in some southern African countries, while T. tubaeformis was invasive in Swaziland, South Africa, Zambia and possibly also Zimbabwe. According to the majority of respondents in Zambia, T. diversifolia has negative impacts on native vegetation, mobility or access, water availability, crop yields and animal health.
Conclusion: Invasive Tithonia species are widespread and spreading throughout much of Africa. Livelihood and biodiversity costs have not been considered by those actively promoting the use and further dissemination of T. diversifolia. We therefore recommend that detailed cost–benefit studies should be undertaken to support informed decisions on the future management of these species.
Description
CITATION: Witt, A. B. R., et al. 2019. Distribution of invasive alien Tithonia (Asteraceae) species in eastern and southern Africa and the socio-ecological impacts of T. diversifolia in Zambia. Bothalia 49(1). doi:10.4102/abc.v49i1.2356
The original publication is available at https://journals.abcjournal.aosis.co.za/index.php/abc
The original publication is available at https://journals.abcjournal.aosis.co.za/index.php/abc
Keywords
Biological invasions -- Africa, Southern, Tithonia (Asteraceae) -- Effect of global warming on, Alien plants -- Economic aspects, Invasive species -- Management, Introduced organisms -- Health aspects -- Africa
Citation
Witt, A. B. R., et al. 2019. Distribution of invasive alien Tithonia (Asteraceae) species in eastern and southern Africa and the socio-ecological impacts of T. diversifolia in Zambia. Bothalia 49(1). doi:10.4102/abc.v49i1.2356