Abstract
The predictive success of risk assessments is still largely a function of invasiveness elsewhere. Therefore, species that are invasive elsewhere should be prioritised for management, and where possible eradicated. We set out to investigate the threat posed by the alien climber Epipremnum aureum (Araceae) and assess techniques for controlling the spread of the species in South Africa. Epipremnum aureum is highly invasive in Hawaii and Sri Lanka, and has recently been considered as a potential invader in South Africa. However, no study has examined the invasion dynamics of the species. We mapped the species' current distribution in South Africa, modelled its potential distribution globally, and explored control methods. We only recorded the species in the KwaZulu-Natal province of South Africa, comprising 78 naturalized populations and 321 cultivated populations. Delimitation surveys of the naturalized populations revealed ~187,000 plants over ~3ha. Several of these populations comprised plants as tall as the trees they were growing on, and were often found flourishing in dump sites, along roadsides or as a result of escaping cultivation. Species distribution models showed that E. aureum has a high probability of expanding its current range primarily along the coastal regions of South Africa and into neighbouring countries on Africa's eastern seaboard. Due to the invasion threat of the species, we recommend that all plants outside cultivation be removed. To achieve this, we found that applying herbicides to freshly cut stems significantly reduced plant growth. Given the species' limited dispersal ability and effective chemical control methods, we propose that E. aureum should be listed as category 3 under NEM:BA A&IS regulations, i.e. naturalized populations need to be managed, it cannot be propagated or sold in future, but current garden plantings may remain.
Highlights
Biological invasions are a global threat to agriculture, natural ecosystems, human and animal health, biodiversity and the economy (Drake et al, 1989; Vitousek et al, 1997; McNeely, 2001; Davis, 2009; Pimentel, 2011; Mazza et al, 2014)
We used the Australian Weed Risk Assessment protocol (A-WRA) to categorize the risk of invasiveness of E. aureum in South Africa based on its biology and ecology, climatic requirements, history, and biogeography (Pheloung et al, 1999)
Questions related to geography and climate, were modified to reflect the conditions of South Africa
Summary
Biological invasions are a global threat to agriculture, natural ecosystems, human and animal health, biodiversity and the economy (Drake et al, 1989; Vitousek et al, 1997; McNeely, 2001; Davis, 2009; Pimentel, 2011; Mazza et al, 2014). Understanding pathways of introductions is important if species invasions are to be effectively regulated (Essl et al, 2015). Humans have both intentionally (e.g. import for horticulture) and unintentionally (e.g. as contaminants or stowaways) introduced species into new environments (Mack and Lonsdale, 2001; Reichard and White, 2001; Dehnen-Schmutz et al, 2007; Lambdon et al, 2008; Pyšek et al, 2011). The impact of biological invasions will inevitably continue increasing if management efforts against those species and pathways that pose the greatest threat are not prioritised (Rouget et al, 2016)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
