Exploring species distribution of spring meiofauna (Annelida, Acari, Crustacea) in the south-eastern Alps

The distribution patterns of Alpine crenic meiofauna were studied using a standardised sampling procedure at 110 springs, evenly distributed across both carbonate and siliceous rocks in Trentino (northern Italy). Spring altitude ranges between 170 and 2800 m a.s.l. One hundred and thirty-eight taxa (mainly identified at species level), belonging to the Annelida (39), freshwater Acari (57), Copepoda (24), and Ostracoda (18) were found in springs of the investigated area. Using Canonical Correspondence Analysis, spatial patterns of meiofaunal assemblages at the regional scale were best explained by altitude, water chemistry (mainly related to geology) and water-flow regime; the role of microhabitat structure and anthropogenic disturbance as environmental descriptors was of minor importance.