ORIGINAL PAPER Assessing the quality and usefulness of different taxonomic groups inventories in a semiarid Mediterranean region Daniel Bruno • David Sa ´nchez-Ferna ´ndez • Andre ´s Milla ´n • Rosa M. Ros • Pedro Sa ´nchez-Go ´mez • Josefa Velasco Received: 11 July 2011 / Accepted: 17 February 2012 / Published online: 13 March 2012 Ó Springer Science+Business Media B.V. 2012 Abstract Extensive biological databases are valuables ecological research tools that form the basis of biodiversity studies. However, it is essential to perform an assessment of the inventories’ completeness for their use in ecological and conservational research, and this is especially true for non-emblematic groups. Using four exhaustive databases compiled for four taxonomic groups (aquatic beetles, aquatic bugs, bryophytes and orchids), in a semiarid Mediterranean region, the aim of this study was to estimate the degree of com- pleteness for the inventory of each taxa and to identify those spatial units that could be considered to be sufficiently-surveyed (UTM 10 9 10 km squares). Then, the degree of environmental representativeness of the databases was assessed, as well as those factors that could have caused biased sampling efforts. Lastly, the usefulness of each database for conservational purposes was discussed. The results of the present study highlighted the lack of complete and extensive inventory data; as the best sampled group did not even reach 25% of sufficiently-surveyed squares in the territory (in the case of aquatic bugs) and none of the squares presented reliable inventories in the case of bryophytes. Although these results suggested that recording was skewed by relatively simple climatic variables, the sufficiently-surveyed squares were evenly distributed across physioclimatic subregions, what enables their use in further ecological studies. The authors would like to emphasise the potential of these procedures to locate areas in need of further sampling as well as to aid in the design of more effective regional conservation schemes. Electronic supplementary material The online version of this article (doi:10.1007/s10531-012-0263-9) contains supplementary material, which is available to authorized users. D. Bruno (&) Á D. Sa ´nchez-Ferna ´ndez Á A. Milla ´n Á J. Velasco Departamento de Ecologı ´a e Hidrologı ´a, Facultad de Biologı ´a, Universidad de Murcia, Campus de Espinardo, 30100 Murcia, Spain e-mail: dbrunocollados@um.es R. M. Ros Á P. Sa ´nchez-Go ´mez Departamento de Biologı ´a Vegetal, Facultad de Biologı ´a, Universidad de Murcia, Campus de Espinardo, 30100 Murcia, Spain 123 Biodivers Conserv (2012) 21:1561–1575 DOI 10.1007/s10531-012-0263-9