Multi-set indicators to assess environmental quality using soil microarthropods, plants and humus

The present study used a multi-set indicator approach to evaluate environmental quality in complex ecosystem. The simultaneous analysis of information deriving from different ecosystem scales and/or taxonomic groups was used to achieve a better understanding of the interconnected above- and below-ground ecosystem components. Three indicator sets were utilized in eight sampling sites representative of the main habitats of a Mediterranean area in Central Italy, the Castelporziano Presidential Estate: (1) plant indicators derived from Ellenberg and Hemeroby models; (2) fauna indicators from soil microarthropods; and (3) humus forms and soil parameters from direct measurements. Principal component analysis and Spearman correlation test were performed on the data indicators/parameters matrix to evaluate the agreement of the multi-set in describing environmental quality. Results highlighted significant correlations among the different indicators/parameters. In particular, vascular plants and soil microarthropods represent two independent gradients in assessing ecosystem functioning, whilst humus forms provided similar information on habitat characteristics.