Biogeographical specification is essential for the correct application of Criteria 1 and 3 and certain applications of Criterion 2. In this context the guidelines for the application of the Ramsar Criteria define "bio(geographic) region" as "a scientifically rigorous determination of regions as established using biological and physical parameters such as climate, soil type, vegetation cover, etc." Note that for non-island Contracting Parties, in many cases biogeographic regions will be transboundary in nature and will require collaboration between countries to establish the locations of representative, rare or unique examples of different wetland types. It is also recognised that the nature of biogeographic regionalisation may differ between wetland types according to the nature of the parameters determining natural variation.
There are a variety of different global and supranational/regional biogeographic schemes in use. No single scheme may be universally appropriate or acceptable and Contracting Parties are urged (in the annex to Resolution VII.11) to apply a regionalisation scheme which they determine to be the most appropriate and scientifically rigorous approach available, taking into account that the additional guidance adopted by Resolution IX.1 Annex B (Ramsar Wise Use Handbook 14 "Designating Ramsar Sites", 3rd edition 2007) indicates that it is generally most appropriate to use a continental, regional or supranational scheme rather than a national or subnational one.
Marine bioregionalisation schemes
In 2007 a standardised and hierarchical biogeographic regionalisation of coastal and near-shore marine environments - Marine Ecoregions of the World (MEOW) - was developed by an international partnership including members of the Ramsar Scientific & Technical Review Panel (STRP) and Ramsar Secretariat (Spalding et al. 2007). It presents a nested system of 12 realms, 62 provinces and 232 ecoregions.The classification has wide international consensus since its publication, and is being recommended by the STRP to Ramsar Contracting Parties at COP10 (October/November 2008) for endorsement to application by the Ramsar Convention with respect to coastal and near-shore areas within the scope of the Convention's application.
Terrestrial bioregionalisation schemes
Several biogeographical regionalisation schemes have been developed for use in conservation planning and assessment in terrestrial environments, developed from different approaches and purposes. Four main schemes are provided here:
Udvardy, 1975. A classification of the biogeographical provinces of the world.Bailey, 1998. Ecoregions: the ecosystem geography of the oceans and continents.Olson et al., 2001. Terrestrial Ecoregions of the World: a new map of life on Earth.Robin Abell et al., 2008. Freshwater Ecoregions of the World: A new map of Biogeographic Units for Freshwater Biodiversity Conservation.