Biodiversity Monitoring South Tyrol (BMS) is an ongoing survey of nature in the mountainous region of the Autonomous Province of Bolzano/Bozen (Italy). The monitoring serves not only as basic research but also aims to establish the scientific foundation for political choices related to spatial planning, agriculture, and nature conservation. More detailed information about the regional-scale program of biodiversity monitoring are available at: https://doi.org/10.57749/2qm9-fq40. This dataset depicts year 2 of the project and includes stream benthic invertebrates along with a set of abiotic parameters that have been collected in streams and rivers of South Tyrol, during year 2022 (from March to July). The full dataset of year 1, 2021, can be found here: doi:10.1594/PANGAEA.941503.Organisms were collected through a kick-net sampler (mesh size 500 µm), perturbating an area of approximately 0.05 squared metres per each subsample, closely following the protocols described by Stucki et al. (2019). Chemical analyses on water samples were performed with a portable spectrophotometer within the same day of collection (Hach Lange DR1900). More methodological details can be found in Scotti et al. (2022). Faunal nomenclature fully complies with Fauna Europaea standard (https://fauna-eu.org), whilst the operational nomenclature (column names) refers - where possible - to the list of Darwin Core terms (https://dwc.tdwg.org/list/).

24 reference points which are sampled each year act as control sites: 12352_1, 12352_2, 32232_1 32232_2, 33132_1 33132_2, 13133_1, 13133_2, 13232_1, 13232_2, 31162_3, 31162_8, 32131_1, 32131_2, 32132_1, 32132_2, 32231_1, 32231_10, 32352_7, 32352_4, 33131_1, 33131_2, 33232_1, 33232_2dwc:habitat(1) -> substrate evaluation according to Stucki et al. (2019)mobile blocks: >250mmmoss: bryophyteshydrophytes: submerged spermatophytesparticulate coarse organic matter (PCOM): leaves, wood, rootsbig mineral sediments: rocks, pebbles; 250mm > Ø > 25mmgravel: 25 mm > Ø > 2,5 mmhelophytes: amphibious Spermatophytesfine, organic sediments: mud Ø < 0.1mm; puddles close to the shoresand and silt: Ø Ø 250mmalgae: algae marl or clay