Characterizing river habitat quality using plant and animal bioindicators: A case study of Tirino River (Abruzzo Region, Central Italy)

A study on different types of bioindicator was carried out to detect river habitat quality in Central Italy. It was investigated the effectiveness of different bioindication models based on three biotic components: (i) vascular plants – hemeroby index for aquatic (Hw) and terrestrial species (Hs), and Ellenbergʹs soil nutrients indicator (N); (ii) aquatic macroinvertebrates – extended biotic index (EBI); (iii) soil microarthropods – index of soil biological quality (QBS-ar). The aim of this study was to compare the five independently derived indices, in order to stress their differences and similarities in the two river environmental compartments – aquatic and terrestrial. udy area is located in the Abruzzo region (Italy) and is bordered by National Parks of Gran Sasso (Parco Nazionale del Gran Sasso) and Majella Mountains (Parco Nazionale della Majella). 14 sampling sites along the Tirino river and two on the Pescara river (just off the confluence of the two rivers) were surveyed for the three biotic components of the ecosystem. Vegetation was surveyed by rectangular plots (20 m wide) in two parallel belts: water and shore; aquatic macroinvertebrates were collected according to the extended biotic index standard method, and edaphic microarthropods were extracted in soil sampling according to the index of soil biological quality (QBS-ar) standard method. There was a very good agreement among the indices and Nonmetric Multi Dimensional Scaling (NMDS), carried out on species, distinguishing an upper course with good environmental quality and a lower part of the riverine system with lower environmental quality; this division corresponds to the CORINE Land Cover class of the sites. Mann–Whitney test showed that ordination of sites was differentiated more by terrestrial than aquatic indices. ent among indices and species ordination highlights the fact that bioindicators are related to habitat quality as a result of the multiple ecosystemic interactions among the biotic components of the ecosystem.