THE THEMATIC ASSESSMENT REPORT ON INVASIVE ALIEN SPECIES AND THEIR CONTROL
8
DEFINITIONS, CONCEPTS
AND THE CONTEXT OF 
THE ASSESSMENT
T
he thematic assessment of invasive alien 
species and their control produced by the 
Intergovernmental Science-Policy Platform 
on Biodiversity and Ecosystem Services 
(IPBES) critically evaluates evidence on 
biological invasions2
 and the impacts of 
invasive alien species. In alignment with the United Nations 
Sustainable Development Goals and the Kunming-Montreal 
Global Biodiversity Framework adopted by the Conference 
of the Parties of the Convention on Biological Diversity, the 
assessment outlines key responses and policy options for 
prevention, early detection and effective control of invasive 
alien species and mitigation of their impacts in order to 
safeguard nature, nature's contributions to people, and 
good quality of life.
For the purposes of this assessment, the terms "native 
species", "alien species",3
 "established alien species", 
"invasive alien species", "impacts", "introduction pathways" 
and "drivers" are represented and defined in Figure SPM.1.
The term "biological invasion" is used to describe the 
process involving the intentional or unintentional transport or 
movement of a species outside its natural range by human 
activities and its introduction to new regions, where it may 
become established and spread.
Species introduced to new regions through human activities 
are termed alien species. Invasive alien species represent 
a subset of alien species, being animals, plants and other 
organisms known to have established and spread with 
negative impacts on biodiversity, local ecosystems and 
species. Many invasive alien species also have impacts 
on nature's contributions to people (embodying different 
concepts such as ecosystem goods and services and 
nature's gifts) and good quality of life.4
 Some of the most 
problematic invasive alien species arrive through multiple 
introduction pathways and repeated introduction.
2. This assessment acknowledges that national and local legislation to 
address biological invasions differ between countries and may include 
different definitions appropriate to specific national and local contexts.
3. Multiple alternative terms exist to refer to alien species.
4. Annex III to decision IPBES-4/1.
Invasive alien species are recognized as one of the five 
major direct drivers of change in nature globally, alongside 
land- and sea-use change, direct exploitation of organisms, 
climate change, and pollution.5
 This assessment considers 
how biological invasions are facilitated by all those direct 
anthropogenic drivers, noting that interactions among 
invasive alien species can enable further biological 
invasions. The assessment also considers how biological 
invasions can be influenced by indirect drivers, as identified 
in the IPBES Global Assessment Report on Biodiversity 
and Ecosystem Services: these include demographic, 
economic, sociocultural and technological drivers, as well 
as those relating to institutions and governance. Finally, 
the assessment considers how biological invasions, and 
ultimately the impacts of invasive alien species, can be 
facilitated by natural drivers of change, in particular natural 
hazards (such as floods, storms and wildfires) and by 
biodiversity loss itself.
In the context of this assessment, management of 
biological invasions includes the development of decision 
support tools; prevention (supported by regulation) 
and preparedness planning and actions; eradication, 
containment and control of invasive alien species; site- and 
ecosystem-based management; and ecosystem restoration.
Other important concepts associated with biological 
invasion are defined in the glossary of the assessment 
report. The conceptual basis underpinning the assessment, 
including the IPBES conceptual framework,6
 and the 
methodology for reviewing literature are outlined in chapter 1 
of the assessment report.
5. IPBES (2019): The Global Assessment Report on Biodiversity and 
Ecosystem Services of the Intergovernmental Science-Policy Platform 
on Biodiversity and Ecosystem Services. Brondizio, E. S., Settele, 
J., Diaz, S. and Ngo, H. T. (eds.). IPBES secretariat, Bonn, Germany. 
https://doi.org/10.5281/zenodo.3831673
6. The conceptual framework for the Intergovernmental Science-Policy 
Platform on Biodiversity and Ecosystem Services was approved by 
the Plenary in decision IPBES-2/4 (2013) and updated in decision 
IPBES-5/1 (2017).
THE THEMATIC ASSESSMENT REPORT ON INVASIVE ALIEN SPECIES AND THEIR CONTRO
The thematic assessment report on
INVASIVE ALIEN SPECIES
AND THEIR CONTROL
The IPBES management committee: