Biological Invasions and Ecological Restoration in South Africa

Abstract

Invasive alien plant species can be a major cause of ecosystem degradation in South Africa, and ecosystem recovery may require restoration interventions beyond controlling the target alien species. Active restoration interventions are usually required if legacy effects result from the invasion. Legacy effects may induce regime shifts when thresholds to autogenic recovery are breached. In such cases, active restoration interventions will be required to manipulate the ecosystem along a trajectory to recovery. In some cases, alien control measures may be sufficient to restore a structurally and functionally representative ecosystem, provided that implementation occurs early in the invasion process and that the control methods do not hamper spontaneous regeneration. It is important that key stakeholders discuss and set realistic restoration goals at the project planning stage. Studies on the costs and benefits of ecological restoration indicate that when important services are improved, benefits outweigh the costs of alien clearing (assuming spontaneous regeneration of the native ecosystem). The costs of moderate, active restoration interventions are

Biological Invasions in South Africa: An Overview

“…The next charts progress with the development of a system of preventative measures and risk assessments (Kumschick et al 2020). The following chapters focus on control and rehabilitation-biological control of invasive plants (Hill et al 2020b), mechanical and chemical control of alien plants (van Wilgen et al 2020a), ecosystem restoration (Holmes et al 2020), and alien animal control (Davies et al 2020) (note: the management of aquatic plants and alien species on offshore islands are covered in Part II, together with the status of those invasions). Finally, the human dimensions affecting alien species control projects are addressed in terms of the evidence for how people cause invasions, how they conceptualise them, what effects invasive species have on people, and how people respond to them (Shackleton et al 2020, Chap.…”

Terrestrial Vertebrate Invasions in South Africa

“…One of the best known populations on Robben Island is currently the subject of control (see Chap. 23, Holmes et al 2020), and are noteworthy for unusual dietary behaviours including ingestion of large amounts (up to 2 L) of plastic (C. Wilke pers. comm.…”

Hands-On Ecological Restoration as a Nature-Based Health Intervention: Reciprocal Restoration for People and Ecosystems

“…Estimating, monitoring, and evaluating what success-or at least forward progress against a clear set of goals-will look like in a hotter, drier world affected by climate change may be even more daunting over the next generation (Falk, 2017). However, numerous restoration efforts in hot, dry landscapes have been documented in peer-reviewed literature (Bainbridge, 2007;Holmes et al, 2020;Whaley et al, 2015). These can help guide large-scale restoration of disturbed desert soils as a means to reduce respiratory diseases and other illnesses.…”