Many species have been intentionally introduced to new regions for their benefits. Some of these alien species cause damage, others do not (or at least have not yet). There are several approaches to address this problem: prohibit taxa that will cause damage, try to limit damages while preserving benefits, or promote taxa that are safe. In the present article, we unpack the safe list approach, which we define as "a list of taxa alien to the region of interest that are considered of sufficiently low risk of invasion and impact that the taxa can be widely used without concerns of negative impacts." We discuss the potential use of safe lists in the management of biological invasions; disentangle aspects related to the purpose, development, implementation, and impact of safe lists; and provide guidance for those considering to develop and implement such lists.

Centre for Agroecology Water and Resilience at Coventry University Coventry England United Kingdom

Centre for Invasion Biology in the Department of Botany and Zoology at Stellenbosch University

Centre for Invasion Biology in the Department of Botany and Zoology at Stellenbosch University Stellenbosch South Africa

Centre for Invasion Biology in the Department of Environmental Sciences Faculty of Science at Rhodes University Makhanda South Africa

Centre for Sustainability Transitions at Stellenbosch University Stellenbosch South Africa

Department of Biological Sciences at the University of Toronto Scarborough Toronto Ontario Canada

Department of Horticultural Sciences at Cape Peninsula University of Technology Cape Town South Africa

Institute of Botany at the Czech Academy of Sciences Průhonice Czech Republic

South African National Biodiversity Institute Kirstenbosch Research Centre Cape Town South Africa

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Framing challenges and polarized issues in invasion science: toward an interdisciplinary agenda