The World Reference Base (WRB) for Soil Resources serves as a portal for a range of authoritative resources useful to those engaged in soil classification and mapping. The WRB project, ongoing since 1980, attempts to “reach international agreement on the major soil groups to be recognized at a global scale as well as on the criteria and methodology to be applied for defining and separating them…to facilitate the exchange of information and experience, to provide a common scientific language, to strengthen the applications of soil science and to enhance the communication with other disciplines” (www.fao.org/ag/AGL/agll/wrb/default.stm). These efforts led to the publication, in 1998, of the three‐volume set, World Reference Base for Soil Resources, now in its second edition (published in 2006). The authority and reliability of the print and online output from the WRB project stem from the involvement and collaboration of the International Society for Soil Science, the International Soil Reference and Information Centre, and the FAO.
The WRB portal is easily navigable via links found to the left of every page; however, some pages are quite information‐dense, requiring careful attention to identify and follow content of interest. There are seven significant content areas highlighted in this review – some are text‐based, others present data and maps. News points to reports, such as the WRB Newsletter, as well as to various announcements of interest to soils researchers. There is also a WRB Forum, which includes instructions for subscription to the e‐mail discussion list. At Documents, the user finds publications available to read online or download, including the World Reference Base for Soil Resources (World Soil Resources Report No. 84) and Lecture Notes on Major Soils of the World (World Soil Resources Report No. 94). Information about translations of World Reference Base for Soil Resources, found at the WRB Translations link, provides contacts for order placement for those translations unavailable for immediate download at the site. There are French, Spanish, German, Lithuanian, Vietnamese, Italian, Romanian, and Polish versions, with a Japanese translation in progress.
The clear value of this portal, for the knowledgeable user, comes from its soil data and mapping information. Soil Maps leads the user to the WRB Dominant Soil Map and the WRB Soil Resources Map, both of which are available as Flat Polar Quartic projections. Each of these maps indicates the global locations of up to 30 reference soil groups (e.g., leptosols, acrisols). An enlarged version of the Dominant Soil Map, derived from FAO‐GIS data from 1999, is available as a.gif image; it is collocated with a table of estimated surface areas of the soil groups. The Soil Resources Map (scale 1:25.000.000) is available for download in.jpg or.eps format; there also are ARC/Info export (zipped) files for two views of this map: World Soil Resources Coverage in Geographic Projection as well as the Flat Polar Quartic projection mentioned earlier. Collocated with the Soil Resources Map information are succinct descriptions of the 30 reference soil groups. There are companion distribution maps for 29 of the 30 soil groups, based on FAO‐GIS data from 1998, with accompanying definition and distribution description. There is no distribution map provided for the soil group anthrosols (absence unexplained). A Classification Key leads the user through the characteristics of each of the 30 soil reference types. Finally, researchers expand on soils classification by presenting, under the link Topsoil Characterization, a downloadable draft document entitled Topsoil Characterization for Sustainable Land Management with Annex A (topsoil properties and their description) and Annex B (examples), with a call for comments and criticisms.
The research data presented at this portal appear to be excellent. However, the currency of some of the information and site maintenance are of concern. For example, the most recent online issue of the WRB Newsletter dates from July 2008. The WRB Forum promises to archive messages and present these at the site, but none are found. The Japanese translations apparently are still in progress, given that the last update of the WRB Translations page was in late 2005. Of greatest concern, the Soil Maps pages are unchanged after more than six years. Perhaps the lack of an update reflects the pause before the next release of information – there were six years between the first and second editions of World Reference Base – but it seems unusual that these data‐driven pages could offer nothing new. Given these concerns and uncertainties, World Reference Base for Soil Resources is a recommended – with reservations – portal for informed researchers in soil science served by academic, research, or special libraries.
