To prepare the Principles of Sustainable Use (the Addis Ababa Principles), which were adopted by the Conference of Parties to the Convention on Biological Diversity in Kuala Lumpur in 2004, the Secretariat of the Convention organised a series of workshops on sustainable use. The last (fourth) workshop in Addis (see www.biodiv.org document UNEP/CBD/WS-Sustainable Use/4/4) formulated 12 desirable properties of indicators. These were:

  1. Unequivocal and reliable descriptors of a specific measurable characteristic;
  2. Sensitive to change in components and systems subject to impact of use;
  3. Viable;
  4. Amenable to use of appropriate technology;
  5. Repeatable;
  6. Relevant to the impact of management;
  7. Acceptable to all stakeholders by mutual agreement;
  8. User-friendly for resource managers/users;
  9. Appropriate to scale of management;
  10. Appropriate to social and cultural context of resource managers/users;
  11. Able to show trends;
  12. Conducive to sound analysis.

The same workshop adopted five components of biological diversity, viz., (1) genetic material, (2) populations, (3) species, (4) communities or assemblages, and (5) "ecosystems, habitats and other aggregated terms". For each of these five components, measurable parameters and elements to be assessed for measuring their decline were defined, and for all these elements indicators were formulated. This framework of analysis is presented here at the IUCN Congress.

As an example the proposals for populations are:

Category of component

  • Populations

Parameters measured

  • A measurable reduction in the distribution and numbers of individuals of a population or increase in fragmentation or decrease in size of population range

Elements to be assessed

  • Population size
  • Extent of distribution
  • Fragmentation
  • Population structure
  • Production potential

Indicators

Population size:

  • number of individuals (and other indices of abundance)
  • biomass or volume
  • density

Extent of distribution:

  • extent of occurrence (sq. km)
  • area of occupancy (presence/absence)
  • area of habitat loss
  • evenness of distribution

Fragmentation:

  • number of sub-populations
  • area of habitat loss
  • change in habitat

Population structure:

  • age structure
  • sex ratio

Production potential:

  • reproductive success and
  • recruitment
  • fecundity
  • physical/physio-logical condition

Similar tables for the four other components were discussed. All this work is to be subject to further development under the guidance of the CBD Secretariat and includes an electronic forum.

Professor Herbert H.T. Prins is of the Wageningen University, The Netherlands. Email: herbert.prins@wur.nl