Data sources
Vegetation data sources and formats
Vegetation databases
Millions of vegetation plots have been collected and partly digitized for local and regional purposes. However, access to this massive and distributed resource was extremely limited prior to the advent of modern databases and digital communication. Furthermore, the advent of the database program Turboveg (see Hennekens & Schaminée 2001) and its widespread adoption stimulated the development of regional and national vegetation databases in many countries owing to the consistent formatting of data across multiple projects. Rodwell (1995) gave the first major overview on existing vegetation-plot data in European countries without specifically differentiating computerised data and came to the conclusion that “well over 1 million relevés” were available on this continent alone. Schaminée et al. (2009) estimated the number of plots from Europe as 4.3 million, with more than 1.8 million stored electronically. Progress has been made in other countries as well, with mature national plot databases having been developed for many countries, such as the United States, New Zealand, and South Africa.
GIVD
Recently, an international initiative has been launched to start a Global Index of Vegetation-plot Databases (GIVD) (Dengler et al. 2011). GIVD is a metadatabase that provides an overview of exiting data, allow researchers to retrieve suitable data for specific research questions, and thus enhance the awareness and application of this valuable but underestimated source of biodiversity information.
Exchange formats: Veg-X
A new effort to develop a core semantic model for observational data in the ecological and environmental sciences is underway (TDWG Observations Task group). While this observational data model has much potential for unifying all observational data, it is still several years away. Meanwhile, a vegetation exchange schema has been created (Veg-X) that provides the immediate opportunity to begin organizing vegetation data, and making them available to the entire ecological community (Wiser et al. 2011).