Managing complex taxonomic data in an object-oriented database

Taxonomists in the Royal Botanic Garden, Edinburgh, specialise in the classification of flora from around the world. The classification of flora is a complex task involving historical records, literature references and specimens collected from the field. Using this information the taxonomists formulate classifications which are continually under review and vary between taxonomists. Currently the taxonomists at RGBE use an application called Pandora, which has been developed using a relational database [PP94], to manage their classification information; however the system is limited in the support required to model and manage this type of information. A review of current systems (e.g. [Pan93] [WAW93] [BPB93] [SLPS95]) showed that most of them are not built with the purpose of storing multiple-overlapping (and possibly contradictory) classifications, and the few that try do not offer a suitable environment for taxonomic work [RBK99a]. Object oriented databases are seen as a possible solution to supporting the work of the taxonomists and a study was undertaken to investigate the migration of Pandora from a relational to an object-oriented database [Rag97]. This project highlighted some problems that classical OO environments are not able to support taxonomic data (e.g. recursive or graph behaviour or full support for aggregate concepts), and justified further research. The purpose of this work is to investigate the issues associated with handling taxonomic data and provide taxonomists with better tools for their work.