TDWG GEOGRAPHY SUB-COMMITTEE

Co-convenors of the committee

Neil Brummitt (Herbarium, Royal Botanic Gardens, Kew)

n.brummitt@rbgkew.org.uk

Rafaël Govaerts (Herbarium, Royal Botanic Gardens, Kew)

r.govaerts@rbgkew.org.uk

Committee members

M.T. Almeida (University of Coimbra) talmeida@ci.uc.pt

S. Davis (Centre for Economic Botany, Royal Botanic Gardens, Kew)

s.davis@rbgkew.org.uk

P. Dávila (UNAM, Mexico) pdavilaa@redvax1.dgsca.unam.mx

E. Forero (University of Bogota) eforero@ciencias.ciencias.unal.edu.co

H. Gillett (World Conservation Monitoring Centre, Cambridge)

harriet.gillett@wcmc.org.uk

P.M. Kirk (CABI Bioscience, Egham) p.kirk@cabi.org

J.-N. Labat (Muséum National d’Histoire Naturelle, Paris) labat@mnhn.fr

J.S. Peterson (USDA, Baton Rouge) scott.peterson@usda.gov

Y. Roskov (Komarov Botanical Institute, St. Petersburg)

roskov@herb.bin.ras.spb.ru

E. Vitek (Naturhistorisches Museum, Vienna) ernst.vitek@nhm-wien.ac.at

Availability of the TDWG Geography standard

The standard as a soft-back 137 page book is available from the Hunt Institute for Botanical Documentation, Carnegie Mellon University, Pittsburgh, U.S.A.

The standard in electronic form as a pdf file, the codes and their designations from Levels 1 to 4 (both as MS-Access and text-delimited files), and the map files, is accessible from the TDWG web site (http://www.tdwg.org/geo2.html).

Digitised georeferenced maps for use with GIS are available from the web site of the Royal Botanic Gardens, Kew (http://www.rbgkew.org.uk/gis/tdwg).

The TDWG Geography standard: uses, status and progress

Geographical data: its structure and function

In compiling taxonomic data, various additional pieces of information are needed to enhance the usefulness of this data. One of the most important is the recording of geographical localities. Since different species are found in different places, after asking the fundamental question of “What is it?” there comes the inevitable question of “Where is it from?”. The TDWG Geography data standard provides a baseline framework for recording the distributions of organisms.

A list of taxonomic names in itself is useless without being set in context. We need to know where different species are found if we are to be able to conserve and/or utilise them. Although this need might best be served by a complete specimen database recording the latitude and longitude of each collection of each species, this remains a long way off. In any case, even with such a database, we will need to be able to produce summary lists of species known from particular areas. To do this, we need to be sure that our concepts of these areas are consistent.

As an example, is a list of plant species from “France”, meaning mainland France, going to be compatible with a list of, say, fish from “France” including the island of Corsica?

In our colloquial use of geographical names, the same areas of the world are often defined in different ways by different people. Although the islands of Hawaii are politically a state within the United States of America, in common usage the ‘United States’ is used to mean ‘the contiguous States’, and Hawaii is not thought of as being a ‘State’ of America but a group of islands in the Pacific Ocean. Similarly, Alaska is often treated as separate geographically, even though not politically, from the United States (i.e. not within the ‘contiguous’ States), and the Aleutian Islands are sometimes treated as separate from Alaska. In short, we have conflicting needs in our political and our geographical usage of the world’s areas.

The TDWG Geography data standard exists to resolve these conflicts through providing a set of ‘biological’ countries within a simple hierarchical framework, with a standardised nomenclature. In TDWG terminology, it is an authority standard, rather than a semantic or data transfer standard, designed to apply a set of values uniformly as descriptors of related data objects. It has several principal features:

·        The scheme is a classification of geo-political units

·        The scheme is hierarchical in structure

·        Each unit in the scheme at each level is assigned a unique alpha-numeric code

·        The smallest units are each mapped to corresponding units of ISO Standard 3166

·        The names used for units recognised in the scheme follow those of the Times Atlas

Since at the lowest level each unit is assigned its corresponding ISO code, this means that taxonomic checklists can be generated for any political entity. For example, all parts of the world which are politically a part of the United States of America carry the ISO code “US”, so by querying for “US” any list of species would automatically include those for Alaska and the Hawaiian Islands, even though within the Geography standard these are classified separately from the contiguous United States. Equally, species lists can be generated purely for the contiguous United States by querying with the appropriate TDWG Geography codes.

The TDWG Geography Standard, 2^nd edition

Since first being published in 1992, the standard has been widely adopted throughout the taxonomic community. Examples of large projects with distributions based on TDWG codes include the 1997 IUCN Red List of Threatened Plants (Walter & Gillett, 1998), volumes of the World Checklist and Bibliography Series of major plant groups at the Royal Botanic Gardens Kew (e.g. Govaerts, Frodin & Radcliffe-Smith, 2000; Farjon, 2001), and a complete database of distributions of all vascular plant genera. As an existing data standard, we try to minimise subsequent changes to the data, otherwise the data would not be “standard”. Over time, however, changes in the global political community necessitate changes to the Geography Standard. The second edition of the TDWG Geography Standard was produced just before the Sydney TDWG meeting in October 2001, and advertised both at that meeting and on the TDWG website.

The impetus for producing a second edition was the ongoing political changes which had occurred in the world, such as a completely new political structure within South Africa, and the recent independence of newly-recognised countries such as from within the former Yugoslavia. This was also seen as the opportunity to correct aspects of the first edition which, with hindsight, were considered mistakes, such as the splitting of Mexico between different continents, and the loose affiliation of the geographically-incoherent region of the North Indian Ocean. In all, there were several changes at all hierarchical levels, summarised in the introduction to the second edition. More importantly, this time electronic publication was seen as integral to the second edition, rather than an additional extra. The whole standard was made available as a pdf document and the hierarchical scheme as both text-delimited files and as an MS Access database (either directly from me or from the TDWG website), along with GIS shapefiles for spatial analysis. The shapefiles have been downloaded by approximately 1,000 users over the past year, although there is no real way to assess the extent to which each user has made use of them.

The working of the TDWG Geography working group

            The working group is predominantly a committee who exist to rule on proposed changes to the data standard. It consists of a number of taxonomists (principally botanists) and database managers from around the world who, collectively, have a great deal of experience with both practical alpha taxonomy and taxonomic databases. It includes, amongst others, members from the World Conservation Monitoring Centre, the United States Department of Agriculture, the Royal Botanic Gardens Kew, and a mycologist from the Commonwealth Agricultural Bureau, all of whom are heavily involved in the design and active compilation of taxonomic databases. We function primarily as an email committee (indeed, I have never met most of my co-committee members), and the co-convenors alert the committee to potential changes required within the data standard, possible ways in which this could be accommodated within the standard, and present a series of alternatives on which the committee then votes. One of the most frequent types of changes is caused by changes to ISO codes, and we are alerted to these via an email digest from the International Standards Organisation. Decisions are made by a two-thirds majority vote. We have taken the decision to only release new editions of the data standard after several years, though as yet there is no guideline as to exactly when new editions should be released, only when the committee feels there have been a sufficient number of new changes to justify it.

Future developments of the TDWG Geography standard

            It has been suggested from within the working group that the existing standard was poorly designed to cope with records of aquatic organisms, not only aquatic plants but more importantly, given that the remit of TDWG now includes zoological disciplines as well, increasing numbers of aquatic animals as well. For example, many lakes or rivers form the boundary between adjacent geo-political regions, though their exact position seemed to be in doubt and it was not known, in many cases, in exactly which region to place a particular record from, say, Lake Victoria. At the last Business Meeting I raised the question of whether or not it would be desirable to extend the geographical coverage of the scheme to include freshwater areas, and beyond that, whether we should also consider covering the oceans, not just grouping islands together into higher geographical units.

            It was agreed in principle that this would be a worthwhile aim, particularly for freshwater regions, and I then asked for suggestions from the audience. Several were suggested:

·        Simply adopt an existing aquatic standard or approach

·        Follow existing geo-political boundaries even as they cross freshwater bodies, and the limits of existing international territorial waters

·        Follow the limits of the continental shelf for countries bordering the oceans, thus distinguishing between two largely distinct marine faunas

·        Recognise the freshwater bodies as separate regions in their own right

            As existing approaches, the Fauna Europaea and FishBase database projects were suggested. It was noted that in general, however, freshwater zoogeographers used river drainage basins as their recording unit, which may not be compatible with the geo-political approach of the existing Geography standard (most countries contain several drainage basins, and some drainage basins span several countries). Following existing geo-political boundaries was not felt to be a satisfactory arrangement when that meant that different halves of the same river were in different regions. As regards the idea of setting country boundaries at the edge of the continental shelf, it was pointed out that some countries, such as New Guinea and Australia, or Britain and the rest of Europe, were connected by continuous continental shelf, so some arbitrary boundary would need to be set. Recognising some bodies as separate regions was seen as a sensible solution, at least for large lakes bordering different regions, such as the Great Lakes of North America or the Rift Valley Lakes of Africa.

            Possibly the best solution will be to arrive at some combination of approaches, and we feel that we should spend our time during the coming year consulting widely both within the working group and outside in the wider zoological and geographic community, and prepare a consistent approach to be outlined at the next TDWG meeting. It is not expected that the full expanded scheme will be produced within that time, merely that we should aim to outline our possible approach by then.

References cited:

Farjon, A. 2001. World Checklist and Bibliography of Conifers. Royal Botanic Gardens, Kew.

Govaerts, R., Frodin, D.G. & Radcliffe-Smith, A. 2000. World Checklist and Bibliography of Euphorbiaceae, 4 Volumes. Royal Botanic Gardens, Kew.

Walter, K.S. & Gillett, H.J. (eds.) 1998. 1997 IUCN Red List of Threatened Plants. Compiled by the World Conservation Monitoring Centre. IUCN, Gland, Switzerland & Cambridge, U.K.