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New framework to protect World Heritage Sites against invasive species
Author: Corporate Communication & Marketing / Korporatiewe Kommunikasie & Bemarking [Alec Basson]
Published: 21/09/2020

A team of international scientists, including three researchers affiliated with the Centre of Excellence for Invasion Biology (CIB) at Stellenbosch University, came up with a new monitoring and reporting framework to help protect World Heritage Sites (WHS) from almost 300 different invasive alien species (microorganisms, animals and plants) that have been introduced to them.

They assessed the current status of biological invasions and their management in 241 natural and mixed WHS globally  ̶  including South Africa's Barberton Makhonjwa Mountains, Cape Floristic Region, iSimangaliso Wetland Park and Vredefort Dome  ̶  by reviewing documents collated by UNESCO and the International Union for Conservation of Nature (IUCN). The findings of their research were published in Biodiversity and Conservation recently.

“Our review yielded limited information on the presence, threat, and management of invasive alien species within many World Heritage Sites. Reports on the status of biological invasions were also inconsistent at times," says lead author Dr Ross Shackleton from the CIB and the Institute of Geography and Sustainability at the University of Lausanne in Switzerland.

Shackleton adds that the lack of a systematic method of reporting made it very difficult to compare information between sites to produce summaries of global trends.

“Detailed information on invasive alien species management undertaken in World Heritage Sites was available for fewer than half of the sites that listed them as a threat. This clearly highlights the need for a good monitoring and reporting framework for biological invasions in World Heritage Sites and other protected areas globally."

Shackleton says their framework proposes protocols for collecting information and reporting on (i) pathways by which alien species are introduced to WHS, (ii) current alien species that are present, (iii) their impacts and management, (iv) predicting future threat and management needs, and (v) identifying the status of knowledge and gaps. All of this information can be used to assign an overall 'threat score/level' (very high, high, moderate, low, or data deficient) to a specific site.

“A key facet of the new framework involves the listing all alien invasive species present. This information will allow the tracking of changes in threats and the implementation and level of success of managing these species."

The scientists tested their framework on seven sites across the world including the Vredefort Dome in South Africa. Shackleton says applying it to these sites has yielded more information than past monitoring initiatives.

“For example, the invasive alien species threat level indicated in the 2017 IUCN World Heritage Outlook for the Serengeti, Keoladeo, Donana, and the Vredefort Dome sites was 'data deficient' or 'low threat' or 'not listed', whereas all of these World Heritage Sites are now categorised as facing moderate to high threats from biological invasions based on our assessment informed by the framework." He adds that some successes in management were also uncovered where Aldabra Atoll has fewer species present due to good management.

Shackleton says hopefully their framework would improve the consistency, comparability and overall value of future reporting on the threats and management of invasive alien species in WHS and other protected areas.

“Applying this framework in World Heritage Sites and other protected areas would help facilitate comparisons and the sharing of best practices between sites and help to guide the allocation and prioritisation of funding to manage invasive alien species. It could also provide the basis for a freely available global information system with an inventory of invasive alien species threats to these areas."

Echoing Shackleton's sentiment regarding the importance of protecting these areas, co-author Prof Dave Richardson from the CIB says “World Heritage Sites face rapidly growing threats from a range of biological invasions which impact upon native biodiversity and the delivery of ecosystem services. Not only that, but invasive alien species are a financial burden as costs for management can be extremely high."

The scientists suggest that monitoring and reporting should preferably be done by local experts or managers while state authorities, in partnership with local role-players, should drive the implementation of the framework.

  • SOURCE: Shackleton, R.T. et al*. 'Biological invasions in World Heritage Sites: current status and a proposed monitoring and reporting framework'. Biodiversity and Conservation. DOI: 10.1007/s10531-020-02026-1

*Authors of this paper include Ross Shackleton (Centre of Excellence for Invasion Biology – CIB – Stellenbosch University/ Institute of Geography and Sustainability, University of Lausanne), Bastian Bertzky (Joint Research Centre, European Commission), Louisa Wood (Centre for Environment, Fisheries and Aquaculture Science, United Kingdom), Nancy Bunbury (Seychelles Islands Foundation/ Centre for Ecology and Conservation, University of Exeter), Heinke Jäger (Charles Darwin Foundation), Remco van Merm (International Union for Conservation of Nature – IUCN), Christian Sevilla (Galapagos National Park Directorate), Kevin Smith (IUCN), John Wilson (CIB/ South African National Biodiversity Institute ), Arne Witt (Centre for Agriculture and Biosciences International, Nairobi) and David Richardson (CIB).

Photo: Vredefort World Heritage Site: Credit: Wikimedia Commons


Dr Ross Shackleton

Centre of Excellence for Invasion Biology/ Institute of Geography and Sustainability

Stellenbosch University/ University of Lausanne


Prof Dave Richardson

Centre of Excellence for Invasion Biology

Stellenbosch University



Martin Viljoen

Manager: Media

Corporate Communication and Marketing

Stellenbosch University