Distribution of invasive alien Tithonia (Asteraceae) species in eastern and southern Africa and the socio-ecological impacts of T. diversifolia in Zambia

Authors

  • Arne Witt Centre for Agriculture and Biosciences International (CABI)
  • Ross Shackleton Department of Botany and Zoology, Stellenbosch University
  • Tim Beale Centre for Agriculture and Biosciences International (CABI)
  • Winnie Nunda Centre for Agriculture and Biosciences International (CABI)
  • Brian Van Wilgen Department of Botany and Zoology, Stellenbosch University

Keywords:

Biological invasions, benefits, costs, invasive species, human well-being, livelihoods, Tithonia, weed

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.

Author Biographies

Arne Witt, Centre for Agriculture and Biosciences International (CABI)

Centre for Agriculture and Biosciences International (CABI), Nairobi, Kenya

Ross Shackleton, Department of Botany and Zoology, Stellenbosch University

Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, South Africa

Tim Beale, Centre for Agriculture and Biosciences International (CABI)

Centre for Agriculture and Biosciences International (CABI), Egham, United Kingdom

Winnie Nunda, Centre for Agriculture and Biosciences International (CABI)

Centre for Agriculture and Biosciences International (CABI), Nairobi, Kenya

Brian Van Wilgen, Department of Botany and Zoology, Stellenbosch University

Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, South Africa

Published

2019-01-20

How to Cite

Witt, A., Shackleton, R., Beale, T., Nunda, W., & Van Wilgen, B. (2019). Distribution of invasive alien Tithonia (Asteraceae) species in eastern and southern Africa and the socio-ecological impacts of T. diversifolia in Zambia. Bothalia, African Biodiversity & Conservation, 49(1). Retrieved from https://abcjournal.org/index.php/BothaliaABC/article/view/24

Issue

Section

Original research, Reviews, Strategies, Case studies