EnvThes – interlinked thesaurus for long term ecological research, monitoring, and experiments

Abstract

The long term ecological research and monitoring is resulting in a vast amount of data describing environmental characteristics, drivers and pressures. Despite harmonisation efforts in the field of methods and observation designs within the frame of LTER Europe or other related networks, different management solutions, together with a varying set of terms and concepts describing the data, are often used for local data management. Therefore, there is not only the need for syntactic but also semantic harmonisation in order to ensure data exchange for cross site and cross domain analysis. The use of a common controlled vocabulary or thesaurus is the first step to enable semantic harmonisation across a network of sites. Within the European scale projects EnvEurope (LIFE08 ENV/IT/00399) and ExpeER the development of a controlled vocabulary for long term ecological research and monitoring was started in order to provide a common set of terms and concepts used in this domain. It is called EnvThes and implemented as SKOS/RDF based thesaurus using poolParty as management tool. PoolParty offers a web browser based viewing and editing interface, as well as a linkedData interface and a SPARQL endpoint. EnvThes is based on existing vocabularies, like US-LTER controlled vocabulary, EUNIS Habitat list, Catalogue of Life, NASA Units, extended by concepts which are additionally needed. Links to the original sources and to matching concepts within commonly used thesauri like EUROVOC, GEMET, AGROVOC or EarTh are established, thus overcoming the islands of conceptual models, developed for different purposes. These links to slowly changing vocabularies, like EUROVOC or GEMET are the anchors for stable semantics; and the LTER specific concepts, for which no linkable equivalent can be found in those thesauri, are the building blocks of a flexible conceptual model, needed by science. EnvThes provides keywords for the metadata system DEIMS, and is used for semantic annotation of the data in the EnvEurope data repository. It can additionally be used as source of terms and links to concepts for any sort of document (for example a Microsoft Excel spreadsheet, Word document, PowerPoint presentation, LATEX document, etc.) used in the LTER context.