Black List Project Background

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Black Listing Invasive Species for Monitoring and Reporting 

          A GEO BON Essential Biodiversity Variable Project 2014-2015


Invasive alien species are second only to habitat transformation in documented severity of impacts on biodiversity. The recent IPCC 5th Assessment Report acknowledges that species movements beyond their historic distributions will continue, driven largely by increased volumes of trade and increasingly complex trade routes. In many cases invasion and climate change interact to increase the likelihood of the establishment, growth, spread and survival of species. Monitoring species movements and geography is therefore essential for understanding and tracking global change consequences. 

Although several indicators were developed and adopted for the purpose of reporting on the state of global invasion for the 2010 Biodiversity Target, these were retrospective. They relied entirely on the collation of data across multiple existing sources and retrospective fitting of these for the purpose of delivering meaningful indicators. While this was essential at the time, given the short time frame and limited capacity at national scales, this approach is not adequate for a sustainable, representative and robust long-term observation system for invasive species.

The key gaps and challenges to achieving an adequate observation system for biological invasion include highly uneven distribution of capacity and baseline information across countries, the highly fragmented nature of available data on invasions, and the lack of adoption of a standardised operational terminology and process for monitoring, identifying and prioritizing invasive species.

Biodiversity science, and invasion biology specifically, has over the last several decades produced a wealth of conceptual and evidence-based generalisations upon which a standardised observation system for invasive species can be designed, as well as assessment criteria for monitoring. While the scientific underpinning for such a process and product is comprehensive, what is lacking is application of this understanding for the purpose of a black listing process, along with consensus support for the structure of such a process.

The combination of the Essential Biodiversity Variable (EBV) concept along with the profile of GEO BON and broad expertise amongst its participants provides a well-timed opportunity to significantly advance a scientifically robust global framework for this key driver of biodiversity change.


Participant Role/expertise  Organisation 
Melodie A. McGeoch     Project Lead: invasion biology, indicator development, monitoring, invertebrates Monash University, Australia
Piero Genovesi Invasion biology, Europe, mammals Institute for Environmental Protection and Research, Italy
Richard Gregory Species distribution modelling, species monitoring, birds RSPB Centre for Conservation Science, U.K.
Donald Holbern Biodiversity information management for invasive species Global Biodiversity Information Facility, Copenhagen
Cang Hui Abundance and occupancy modelling Stellenbosch University, South Africa
Walter Jetz Species distribution modelling, biodiversity data management Yale University, U.S.A.
Guillaume Latombe Modelling species and community dynamics Monash University, Australia
Petr Pyšek Invasion biology, plants Academy of Sciences, Czech Republic
Mark Costello Marine biodiversity University of Auckland, New Zealand
Marten Winter Invasion biology, biodiversity monitoring, climate change impacts Centre for Integrative Biodiversity Research, Germany


This project is strongly aligned with GEO BON’s mission to advance a global, scientifically robust framework for observations on change in key drivers of biodiversity loss, in this instance, invasive species. The Black Listing approach aims to support monitoring and decisions by leveraging harmonised gathering of new data, facilitate delivery of data on change in the status of biological invasion at a global scale, and provide a mechanism for ensuring data quality and comparability.

Relationship of Black Listing approach with EBVs

Essential Biodiversity Variables (EBVs) are measurements required for the study, reporting, and management of biodiversity change.

EBV Class   EBV       Measurement   Example metrics Relevance to monitoring change in invasion
Species populations Abundance Number of individuals, cover Abundance is one of three key numerical functions in quantifying invasion impact.
Species populations Distribution Presence, absence, occupancy Distribution is a second of three key numerical functions necessary for estimating and tracking changes in invasion impact.
Species traits Biomass Specific leaf area, body size Proxy for impact of invasive species on native communities and ecosystem, particularly by comparison with native taxa.
Ecosystem structure Habitat structure Plant cover(measured in-field or by remote sensing) Measure of impact in the form of displacement of native communities by invasive species. Particularly relevant in invaded plant and intertidal communities.
Ecosystem function Nutrient cycling C:N ratio Invasive plants are known to alter soil nutrients with significant effects especially in nutrient poor native systems.



Aichi Target 9: By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated and measures are in place to manage pathways to prevent their introduction and establishment

The importance of prioritizing and monitoring threats from biological invasions is clearly recognised by the invasive alien species target; Aichi Target 9 under the Convention on Biological Diversity Strategic Plan for Biodiversity 2011-2020 ( Aichi Target 9 recognises that invasive alien species must first be identified and then ‘prioritized’. The information necessary for informed, evidence-based prioritization is extensive but still largely inadequate in many countries.

In addition to identifying and prioritizing pathways of introduction, countries are faced with the challenge of making decisions about invasive species in the absence of adequate data on the presence and distribution of alien species in the country. For countries with little baseline data and insufficient capacity, the application of transparent, structured and as far as possible quantitative and repeatable assessments is also key to monitoring the status of biological invasions.

A general set of guidelines for monitoring trends in invasion status and as a basis for prioritization of invasive species that accommodates the wide array of data adequacy levels across countries is therefore essential to reporting on Aichi Target 9 by 2020, and to the ongoing monitoring of the global status of biological invasion. Importantly, the scheme and associated guidelines proposed here will leverage targeted, on-ground collection of distribution and abundance information for invasive species.


Biological invasion provides an important, topical and effective vehicle for illustrating and communicating the concept and value of EBVs.  The measurements essential for studying, reporting and managing the threat that invasive species pose to biodiversity encompass at least two, and up to four, EBV classes, two core EBVs and a range of additional possibilities.