Invasive Species
Primary reference(s)
FAO, 2007. Invasive species. In: State of the World’s Forests. Food and Agriculture Organization of the United Nations (FAO). Accessed 10 October 2020.
Additional scientific description
Invasive species include species, subspecies or lower taxa of invertebrates, plants, microorganisms and vertebrates non-native (alien or exotic or non-indigenous) to a particular ecosystem and whose human mediated or unintentional introduction and spread causes, or are likely to cause, socio-cultural, economic or environmental harm or harm to human health (FAO, 2007). An alien species is a species, subspecies or lower taxon, introduced outside its natural past or present distribution; it includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce (UNEP, 2002).
Increasing international trade and human mobility, exacerbated by impacts of climate change, have increased the introduction of plant and animal species into new areas where they have become invasive (FAO, 2020).
Estimates of the full costs of biological invasions are rare because of the difficulty in assessing the costs of impacts on biodiversity, ecosystem functions and human health, or other indirect costs such as the impact of control measures. The costs of invasive species to the forest sector have not been studied on a global scale. However, based on a study of six countries (Australia, Brazil, India, South Africa, the United Kingdom and the United States of America), it was estimated that as many as 480,000 alien species have been introduced in agriculture and forestry worldwide, with an annual cost of more than USD 1.4 trillion (FAO, 2007). Invasive plant and animal species are now considered one of the most important causes of biodiversity loss, especially in many island countries (CBD, 2009).
Preventing and reducing the harmful effects of invasive species requires an approach that incorporates biological, ecological and social sciences, economics, policy analysis and engineering. National efforts should include early warning systems, eradication and control, as well as increased awareness and political leadership. Global, regional and bilateral efforts include standards and guidelines, monitoring and assessment, and information and action networks (FAO, 2007).
Numerous international and regional programmes and instruments, binding and non-binding, have been developed to address the problem of invasive species (FAO, 2007).
Different countries have different approaches – two of note are the Invasive Species Definition Clarification and Guidance prepared by the United States Department of Agriculture (USDA, 2006) and the Australian Weed Strategy (Australian Government, 2016).
Metrics and numeric limits
Not available.
Key relevant UN convention / multilateral treaty
The Convention on Biological Diversity (1992) has three main objectives: the conservation of biological diversity, the sustainable use of the components of biological diversity, and the fair and equitable sharing of the benefits arising out of the utilisation of genetic resources (United Nations, 1992). At the time of writing, there were 196 parties to the Convention on Biological Diversity.
The Convention on Biological Diversity (CBD) calls on its parties to ‘prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats, or species’ (Article 8[h]). The parties have adopted a series of 15 guiding principles to lead governments and organisations in developing effective strategies for minimising the spread and impact of invasive alien species (UNEP, 2002). The UN CBD introduced a commitment to endorse these principles in the 2011–2020 Global Biodiversity Strategy by adopting Aichi Target 9 (CBD,2020).
European Commission (Environment) EU Regulation 1143/2014 on Invasive Alien Species (2015). Invasive alien species are animals and plants that are introduced accidentally or deliberately into a natural environment where they are not normally found, with serious negative consequences for their new environment. They represent a major threat to native plants and animals in Europe, causing damage worth billions of Euros to the European economy every year. As invasive alien species do not respect borders, coordinated action at the European level will be more effective than individual actions at the Member State level (European Commission, 2015).
The International Plant Protection Convention (1997) is an intergovernmental treaty signed by over 180 countries, aiming to protecting the world’s plant resources from the spread and introduction of pests, and promoting safe trade (FAO, 1999). The Convention introduced International Standards for Phytosanitary Measures (FAO, 2021) as its main tool to achieve its goals, making it the sole global standard setting organisation for plant health. The International Plant Protection Convention (IPPC) is one of the ‘Three Sisters’ recognised by the World Trade Organization’s (WTO) Sanitary and Phytosanitary Measures (SPS) Agreement (WTO, 1998), along with the Codex Alimentarius Commission for food safety standards and the World Organization for Animal Health (OIE) for animal health standards.
The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). In the IPBES Regional Assessments (IPBES, 2018a) and Global Assessment Report (IPBES, 2019), invasive alien species were identified as one of the main direct drivers of biodiversity loss worldwide. The rapidly growing threat that invasive alien species pose to biodiversity, ecosystem services, sustainable development and human well-being is, however, generally poorly quantified and little understood by decision makers (IPBES, 2018b).
The International Union for Conservation of Nature (IUCN). The IUCN Species Survival Commission (SSC) Invasive Species Specialist Group maintains two global databases: the Global Invasive Species Database (GISD, www.iucngisd.org), which contains profiles of key invasive alien species, and the Global Register of Introduced and Invasive Alien Species (Pagad et al., 2018), which was developed with a mandate of the CBD and collates data on alien species in all taxonomic groups for all nations.
Examples of drivers, outcomes and risk management
Drivers: An increase of introduction and spread of invasive species or invasive alien species (insect pests, pathogens, microorganisms, vertebrates and plants) is due to increasing international trade, travel and the impacts of climate change.
Outcomes: Economic, environmental, social and cultural impacts due to the loss of host trees, loss of crops and loss of biodiversity.
Risk management: This includes the establishment of early warning and early action activities; the implementation of phytosanitary standards in the agriculture and forestry sectors; and increased public awareness and community participation in early warning systems.
The Global Invasive Species Programme (GISP) was established in 1997 to address global threats caused by invasive species and to provide support to the implementation of Article 8(h) of the CBD. To increase awareness and provide policy advice, GISP has prepared the Global strategy on invasive alien species, which outlines ten strategic responses to the invasive species issue (FAO, 2007).
The GISD is a free, online searchable source of information about alien and invasive species that negatively impact biodiversity. It aims to increase public awareness about invasive species and to facilitate effective prevention and management activities by disseminating specialist knowledge and experience to a broad global audience. The GISD focuses on invasive alien species that threaten native biodiversity and natural areas and covers all taxonomic groups from microorganisms to animals and plants (GISD, no date).
The GISD is managed by the Invasive Species Specialist Group (ISSG) of the IUCN SSC. It was developed between 1998 and 2000 as part of the global initiative on invasive species led by the GISP (GISD, no date).
Because invasive species are addressed in different agreements and conventions (e.g., the Convention on International Trade in Endangered Species, IPPC and the World Trade Organization Agreement on the Application of Sanitary and Phytosanitary Measures), many countries have difficulty in keeping up with the reporting requirements (FAO, 2007) In response, the UNEP World Conservation Monitoring Centre (UNEP-WCMC) has recently developed a set of issue-based modules summarising country obligations under the CBD and other conventions, and in 2020 published a report on Building a Multidimensional Biodiversity Index (Soto-Navarro et al., 2020).
References
Australian Government, 2016. Invasive Plant and Animal Committee (2016). Australian Weed Strategy 2017-2027, Australian Government Dept. of Agriculture and Water Resources, Canberra. Accessed 19 April 2021.
CBD, 2009. Invasive alien species. A threat to biodiversity. Convention on Biodiversity (CBD). Accessed 31 October 2020.
CBD, 2020. Strategic Plan for Biodiversity 2011–2020 and the Aichi Targets. Convention on Biodiversity (CBD).
European Commission, 2015. EU Regulation 1143/2014 on Invasive Alien Species, 2015. Accessed 10 October 2020.
FAO, 1999. International Plant Protection Convention (IPPC). Accessed 19 April 2021.
FAO, 2007. Invasive species. In: State of the World’s Forests. Food and Agriculture Organization of the United Nations (FAO). Accessed 10 October 2020.
FAO, 2020. The State of the World’s Forests. Food and Agriculture Organization of the United Nations (FAO). Accessed 31 October 2020.
FAO, 2021. Adopted International Standards for Phytosanitary Measures. Accessed 19 April 2021.
GISD, no date. Global Invasive Species Database (GISD). Accessed 31 October 2020.
IPBES, 2018a. Regional/subregional assessments on biodiversity and ecosystem services. Accessed 19 April 2021.
IPBES, 2018b. Invasive alien species assessment. Accessed 19 April 2021.
IPBES, 2019. Global Assessment Report on Biodiversity and Ecosystem Services. Accessed 19 April 2021.
Pagad, S., P. Genovesi, L. Carnevali, D. Schigel and M.A. McGeoch, 2018. Introducing the Global Register of Introduced and Invasive Species. Scientific Data, 5:170202.
Soto-Navarro, C.A., M. Harfoot, S.L.L. Hill, J. Campbell, H.-C. Campos Santos, F. Mora, C. Pretorius, V. Kapos, H. Allison and N.D Burgess, 2020. Building a Multidimensional Biodiversity Index – A scorecard for biodiversity health. UN Environment Programme World Conservation Monitoring Centre (UNEP-WCMC) and Luc Hoffmann Institute (LHI). Accessed 10 October 2020.
UNEP, 2002. Guiding Principles for the Prevention, Introduction and Mitigation of Impacts of Alien Species that Threaten Ecosystems, Habitats or Species. Annex to COP 6 decision VI/23 of the Convention on Biological Diversity. United Nations Environment Programme (UNEP). Accessed 31 October 2020.
United Nations, 1992. Convention on Biological Diversity. Accessed 29 January 2020.
USDA, 2006. Invasive Species Definition Clarification and Guidance. National Invasive Species Information Center, United States Department of Agriculture (USDA). Accessed 10 October 2020.
WTO, 1998. Understanding the WTO Agreement on Sanitary and Phytosanitary Measures. Accessed 19 April 2021.