Appendix E. Field plot data exchange schema.
Most of the associations and alliances in North America have not yet been described numerically and little is formally known about their ecological characteristics, either in general or individually. A major reason for the lack of knowledge about associations and alliances is that field plot data for them has not generally been available. To date, the only information compiled systematically about alliances in the United States is the set of alliance descriptions developed by NatureServe (2006). Although this is the best available information, few descriptions are linked with field plot data and fewer are linked with field plot data that can be accessed and reexamined. To describe associations and alliances and to investigate their ecological characteristics, either a massive amount of new field plots must be collected or existing data must somehow be used.
The only way that enough field data can be developed for this purpose is to combine data from multiple sources. To facilitate this, VegBank (www.vegbank.org) has been established to archive, integrate, and disseminate the field plot data that will be needed to achieve the NVC goal of quantitative field based and peer-reviewed descriptions of associations and alliances.
At the heart of this endeavor is the technical capability to read and integrate digital files containing field plot data. The most appropriate technology for this is XML, and the operable tool for this purpose is a XML schema (see Sperberg-McQueen and Thompson 2003). The NVC XML Schema defines the structure, content, and semantics of plot data that have been originally generated by many different workers. Legacy data formatted to this schema can be queried and combined. The NVC XML Schema is the fundamental means of formatting and transferring vegetation field plot data.
NatureServe Explorer: an online encyclopedia of life. 2006. Version 4.7. Arlington, Virginia, USA. Available online [http://www.natureserve.org/explorer/].
Sperberg-McQueen, C.M. and H. Thompson. 2003. XML Schema, revision 1.87, W3C, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.