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Combining CBD and IPPC implementation: dealing with ecological complexity in pest risk assessment

Maj De Poorter

Invasive Species Specialist Group (ISSG), IUCN; Centre for Invasive Species Research, University of Auckland, Auckland, New Zealand; e-mail:


Efforts by the Convention on Biological Diversity and International Plant Protection Convention to address the problem of movement and spread of invasive alien species have implications for pest risk analysis. National plant protection organizations responsible for pest risk assessment must deal with a wider scope of pest impacts when environmental risks are included in the analysis. They also will often face a high level of complexity in ecological interactions. This paper provides general recommendations for overcoming such difficulties and outlines how the Invasive Species Specialist Group can provide assistance.

Introduction to the threat to biodiversity

The natural biogeographical barriers of oceans, mountains, rivers and deserts provided the isolation essential for unique species and ecosystems to evolve. In just a few hundred years these barriers have lost their effectiveness; one critical element of economic globalization is the movement of organisms from one part of the world to another through trade, transport, travel and tourism.

Many organisms have been deliberately introduced into new ecosystems in which they are alien species (as defined previously, see section 1). The Convention on Biological Diversity defines "introduction" differently from the International Plant Protection Convention as "the movement by human agency, indirect or direct, of an alien species outside of its natural range (past or present). This movement can be either within a country or between countries or areas beyond national jurisdiction" (CBD, 2002). Many of the deliberate introductions are beneficial to people for food or other economic uses. However, tremendous damage results from those that are detrimental. This paper addresses the latter group: "invasive alien species", namely those species whose introduction and/or spread threaten biological diversity.

Biological invasions by alien species are now considered the second leading factor in biodiversity loss globally; on islands, invasive alien species are considered the main factor contributing to extinctions of native vertebrates (mammals, birds etc). The impacts of invasive alien species on biodiversity and ecosystem functioning are immense, insidious and often complex. Directly or indirectly, these impacts have ramifications for sustainable development and poverty alleviation (see also: Office of Technology Assessment, 1993, Lowe et al., 2000).

As discussed in earlier chapters, Article 8(h) of the CBD requires contracting parties, as far as possible and as appropriate, to prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species. Extensive guidance on how to implement this has been provided (CBD, 2002). Meanwhile, since 1999, the IPPC has been clarifying its role with regards to invasive alien species that are plant pests. In particular, the 2003 revision of ISPM 11: Pest risk analysis for quarantine pests including analysis of environmental risks included in the coverage of environmental impacts:

These efforts by the CBD and IPPC to address the problem of movement and spread of invasive alien species have ramifications for the operations of national agencies responsible for implementing the two conventions.

Implications for pest risk analysis

Including environmental impacts in pest risk assessment means that pest risk analysis will need to deal with a wider scope of impacts and often with a high level of ecological complexity.

The wider scope of impacts would involve the inclusion of, for example, pathogens affecting wild plants. For instance, Phytophthora cinnamomi, causing dieback, is the largest threat to biodiversity in a "hotspot" of native plant communities in southwest Western Australia (Watson, 2003).

Pest risk analysis will also have to deal with ecological complexity. The complexity of impacts in native biodiversity and ecosystem functioning can be very high. National plant protection organizations will need to adapt to the requirements of treating this complexity effectively in pest risk analyses. It is instructive to ask: How prepared are NPPOs to deal with assessing an organism that may not necessarily be harmful on its own but that may allow an invasive alien species to become a "super" invasive alien species? How prepared are NPPOs to deal with the effect of invasive alien plants on such abstruse ecosystem issues as the crocodile sex ratio? How will they deal with the concept of "invasional meltdown", when primary invaders facilitate the rapid development of invasiveness of other alien species?

Examples of the complex ecological impacts that will need to be assessed by NPPOs in pest risk analysis include the following:

In addition to such issues of capability in dealing with ecological complexity in pest risk analysis, there are questions at the level of the overall system. The Agreement on the Application of Sanitary and Phytosanitary Measures (WTO, 1994) is designed to facilitate free trade. Hence its focus is on international obligations to ensure that import restrictions are not a disguised form of commercial protectionism. The SPS Agreement’s mandate does not include ensuring that governments’ standards are adequate to protect environments and biodiversity from the undesirable side-effects of free trade, such as the massive increase in risk of invasions by alien species (Jenkins, 1999). However, discussion of whether or not the SPS system allows for effective dealing with ecological invasive alien species is beyond the scope of this paper.

The way forward

Agencies such as NPPOs deserve the support and encouragement of the international community in tackling the difficulties of maximizing biodiversity outcomes in implementing both the IPPC and the CBD. Recommendations include:


NPPOs have a major role to play here. The making or breaking of new attitudes to consultation, environment and thinking outside the box is often in the hands of NPPOs (or similar agencies), given their relative power within government systems and their resourcing compared with other agencies. NPPOs face challenges, but also have major opportunities to contribute to stemming the tide of biodiversity loss, species extinctions and resulting livelihood impacts.

How the Invasive Species Specialist Group can help

The IUCN Invasive Species Specialist Group serves as an active network of people knowledgeable about invasive species problems and those requiring assistance in their fight against biological invasions. The Office of ISSG is located at the University of Auckland, New Zealand. Its role is global and includes:


CBD. 2002. Sixth Conference of the Parties, The Hague, the Netherlands, 7 - 19 April 2002: Decision VI/23: Alien species that threaten ecosystems, habitats or species to which is annexed Guiding principles for the prevention, introduction and mitigation of impacts of alien species that threaten ecosystems, habitats or species (available at

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Lowe, S., Browne, M., Boudjelas, S. & De Poorter, M. 2000. 100 of the world’s worst invasive alien species: A selection from the Global Invasive Species Database. Auckland, New Zealand, IUCN/SSC Invasive Species Specialist Group (ISSG). 12 pp. Booklet distributed with Aliens 12, December 2000 (available at

Office of Technology Assessment [of the U.S. Congress]. 1993. Harmful non-indigenous species in the United States. OTA-F-565. Washington, DC, USA, U.S. Government Printing Office (available at viii + 391 pp.

Watson, J. 2003. Small is beautiful: conserving the nature of low altitude mountain protected areas in South Western Australia. Presented at the World Heritage Mountain Protected Areas Workshop, Drakensberg, South Africa, 4 - 8 September 2003, at the occasion of the Fifth World Parks Congress, 8 - 17 September 2003, Durban, South Africa.

WTO. 1994. Agreement on the application of sanitary and phytosanitary measures. In: Agreement establishing the World Trade Organization: Annex 1A: Multilateral agreements on trade in goods. Geneva, Switzerland (available at

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