Assessing the quality and usefulness of different taxonomic groups inventories in a semiarid Mediterranean region

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 completeness 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 (

The role of criteria in selecting important areas for conservation in biodiversity‐rich territories

“…A serious impediment in area scoring is the lack of comprehensive data sets. Moreover, scientific literature provides examples of the type of bias found in databases (Bruno et al, 2012;Pardo et al, 2013). This problem was also detected in our study.…”

“…Moreover, scientific literature provides examples of the type of bias found in databases (Bruno et al, 2012;Pardo et al, 2013). Moreover, scientific literature provides examples of the type of bias found in databases (Bruno et al, 2012;Pardo et al, 2013).…”

Estimating the completeness of orchid checklists and atlases: a case study from southern Italy

“…Such index (C) is expressed as a percentage value of the ratio between the number of observed species (S obs ) and the number of estimated species (S est ): C = S obs /S est The most used non parametric estimators for presence/absence data or incidence data are Jackknife, Chao, Bootstrap, and ICE (Gotelli & Colwell 2011;Vallet et al 2012). While the first of these indexes could represent a good compromise (Brose et al 2003), several other authors prefer to compare more than one index (Martinez-Sanz et al 2010;Bruno et al 2012;Garcia-Marquez et al 2012;Vallet et al 2012;Archer 2019). It is therefore noted that the Jackknife estimator gives higher values of estimated richness and, accordingly, lower completeness values than the Bootstrap estimator (Garcia-Marquez et al 2012).…”

“…These limits have been set considering for all the datasets used an average number of five plot sampled in a day. According to the method used in Bruno et al (2012), the cells with completeness >65% have been considered sufficiently studied squares (SSS).…”

“…To assess whether these rates represent a good result (i.e., the area is exhaustively well studied), we can refer to the choice of the limit of 65% to consider a cell as sufficiently studied. In Bruno et al (2012) this completeness limit has been chosen to select a useful number of squares to perform further analysis. These authors, for all the four considered taxonomic groups, get lower portion of squares SSS compared to the portion we get for our studied areas.…”