Biological Invasions as a Component of South Africa’s Global Change Research Effort

Abstract

In this chapter, we assess how much research in South Africa has been directed towards biological invasions relative to other elements of global change. Using Web of Science, we systematically reviewed literature relevant to South African ecosystems published between 2000 and 2018 and relating to biological invasions, climate change, overharvesting, habitat change, pollution, and/or atmospheric CO 2. We identified 1149 relevant papers that were scored in terms of their coverage of drivers and driver interactions that affect biodiversity or ecosystem services. A strong spatio-temporal effect was observed on research effort. Firstly, effort differed between realms, with habitat change, pollution and overharvesting receiving the largest research focus within terrestrial, freshwater and marine/estuarine realms respectively. Secondly, certain globally well-studied phenomena were not documented in local literature (e.g. there were fewer than five papers on ocean acidification). We identified 21 different interactions between drivers, with the interactions between invasive species and habitat change (for example altered fire regimes in invaded landscapes) being the most prominent. However, fewer than 4% of papers addressed interactions between three or more drivers. This suggests that while the importance of understanding driver interactions is recognised, there has been little in the way of researching the compound effects of driver interactions in South African ecosystems. The long-cited statement that invasive species pose thesecond-largest threat to biodiversity conservation, behind habitat change, matches the relative research output for this driver in South Africa. Developing a comprehensive

Impact of Prosopis velutina Wooton on the Composition and Diversity of Native Woody Species in a Semi-Arid Zone along the Molopo River, South Africa

“…Many studies have been conducted to quantify the ecological and socio-economic impacts of alien plant invasions and to develop efficient management approaches [ 18 , 19 , 20 ]. There is limited knowledge of alien plant impact and occurrence in South Africa [ 21 , 22 , 23 ]. However, the potential expansion of the invasive plants in the North-West Province remains underexplored, especially within the riparian areas.…”

Complex interplays between limpets and alien species in South Africa: multispecies interactions, zonation and size effects

“…They are amply living up to the prognosis for the future made in 2008 that by 2025 their rate of spread would have radically increased (Branch et al, 2008a). In South Africa alone, the rate at which alien species have been recorded has escalated exponentially from just one in 1950 to 95 by 2023 (Robinson et al, 2005;Griffiths et al, 2009;Mead et al, 2011a;Mead et al, 2011b;Robinson et al, 2016;Robinson et al, 2020;Van Wilgen et al, 2023). Jennsen (2015) expresses a pessimistic view: 'You have loosed a chaotic, unstable element into the Mosaic.…”