Chapter 4
Invasive Alien Aquatic Plants
in South African Freshwater Ecosystems
Martin P. Hill , Julie A. Coetzee , Grant D. Martin , Rosali Smith ,
and Emily F. Strange
Abstract South Africa has a long history of managing the establishment and
spread of invasive floating macrophytes. The past thirty years of research and the
implementation of nation-wide biological and integrated control programmes
has led to widespread control of these species in many degraded freshwater
ecosystems. Such initiatives are aimed at restoring access to potable freshwater
and maintaining native biodiversity. However, in recent years, there has been a
decline in populations of floating invasive plants, and an increase in the establishment and spread of submerged and emergent invasive plant species, which poses
significant threats to aquatic ecosystems. This chapter highlights the vulnerability
of South Africa’s eutrophic systems to successful colonisation by this suite of new
macrophytes following the successful biological control of floating invasive macrophytes, and explores a new regime shift in invasive populations partly driven by
biological control. We suggest that a more holistic approach to the control of
invasive plants would be required to ensure long-term ecosystem recovery and
sustainability.
M. P. Hill (*) · G. D. Martin · R. Smith
Centre for Biological Control, Department of Zoology and Entomology, Rhodes University,
Makhanda, South Africa
e-mail: m.hill@ru.ac.za
J. A. Coetzee
Centre for Biological Control, Department of Botany, Rhodes University, Makhanda,
South Africa
E. F. Strange
Centre for Biological Control, Department of Zoology and Entomology, Rhodes University,
Makhanda, South Africa
School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
© The Author(s) 2020
B. W. van Wilgen et al. (eds.), Biological Invasions in South Africa, Invading
Nature - Springer Series in Invasion Ecology 14,
https://doi.org/10.1007/978-3-030-32394-3_4
97
Invasive Alien Aquatic Plants
in South African Freshwater Ecosystems
Martin P. Hill , Julie A. Coetzee , Grant D. Martin , Rosali Smith ,
and Emily F. Strange
Abstract South Africa has a long history of managing the establishment and
spread of invasive floating macrophytes. The past thirty years of research and the
implementation of nation-wide biological and integrated control programmes
has led to widespread control of these species in many degraded freshwater
ecosystems. Such initiatives are aimed at restoring access to potable freshwater
and maintaining native biodiversity. However, in recent years, there has been a
decline in populations of floating invasive plants, and an increase in the establishment and spread of submerged and emergent invasive plant species, which poses
significant threats to aquatic ecosystems. This chapter highlights the vulnerability
of South Africa’s eutrophic systems to successful colonisation by this suite of new
macrophytes following the successful biological control of floating invasive macrophytes, and explores a new regime shift in invasive populations partly driven by
biological control. We suggest that a more holistic approach to the control of
invasive plants would be required to ensure long-term ecosystem recovery and
sustainability.
M. P. Hill (*) · G. D. Martin · R. Smith
Centre for Biological Control, Department of Zoology and Entomology, Rhodes University,
Makhanda, South Africa
e-mail: m.hill@ru.ac.za
J. A. Coetzee
Centre for Biological Control, Department of Botany, Rhodes University, Makhanda,
South Africa
E. F. Strange
Centre for Biological Control, Department of Zoology and Entomology, Rhodes University,
Makhanda, South Africa
School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
© The Author(s) 2020
B. W. van Wilgen et al. (eds.), Biological Invasions in South Africa, Invading
Nature - Springer Series in Invasion Ecology 14,
https://doi.org/10.1007/978-3-030-32394-3_4
97