Impact of taxonomic resolution on the indicatory information: studies on carabid beetles in Poland

The informative power of species surrogacy with respect to ecological processes and anthropogenic influences has been rarely studied. Thus, five datasets on carabid beetles collected using pitfall traps were analysed in order to study the impact of changing the taxonomic resolution from species to genus level on their indicatory information: a dataset of eight study sites in differently managed habitats sampled in 2013, a dataset tracing successional changes from 2004 to 2013 in a naturally regenerated pine forest, a dataset of three sites on a heap of power plant ashes and a dataset of four sites on a colliery spoil heap, both sampled from 2004 to 2011, and a dataset of six sites along the roadside of a highway being renovated in 2009, sampled in 2008 and from 2010 to 2012. The datasets were analysed by studying correlations of species numbers with genus numbers and species based Shannon diversity with genus based Shannon diversity, testing compliance between species based and genera based similarity matrices, and comparing the information provided by ordination diagrams based on species information or genus information respectively. The results indicate that at least in our study a substantial amount of information provided by species data is still contained in the genus data, but information about fine graded differences between study sites gets lost. We conclude that, even if carabid genus information might be useful in some cases (e.g. preliminary biodiversity assessment), the limitation to higher taxonomic levels like the genus level has to be done with caution.