This paper describes a system to enable access to those information systems at the National Autonomous University of Mexico that are related to biodiversity and the environment. This system associates existing Geographic Information Systems,
Biodiversity Information Systems, and standard Relational Database Management Systems in a federation. In this way, the system enables researchers to retrieve information using a single query interface, in a format suitable for their particular field of
study, and according to a corresponding set of permissions. The main contribution of this paper is to propose an open-sourced Mediator system compliant with open international standards. This system offers a competitive performance against state of the art Relational Database Management Systems in spatial and non-spatial join operations. Index Terms—mediator system, geospatial information system, biodiversity information system, information system federation, query system