This data is related to a research project using invertebrate ecological data to investigate functional traits at large wood sites. The research took place in the Hammer Stream, United Kingdom. The data was collected between 2016 and 2017 and available as separate .csv files. Two types of data are available: 1. Abundances of invertebrates and Traits Samples were collected with Surber net and colonization pot in two river sections (gravel and sand). Samples were collected over 1 year during 3 sampling events (October-November, March-May and July-August) and from sites were large wood was present and from control sites (large wood was absent). 2 Environmental data Three replicates of hydrological, physical, sedimentological and chemical measurements were taken per sampling site on each sampling campaign. Velocity measurements were taken using a Flow Tracker Acoustic Doppler Velocimeter (SonTek). Discharge was calculated using the velocity-area method. Spot samples of temperature (T, °C), pH, dissolved oxygen (DO, %), electric conductivity (EC, µS cm-1) were measured with a multiparameter probe (Hannah HI98196). Sediment was sampled using cores (diameter 5 cm, depth 25 cm) and analysed for grain size and loss on ignition analysis. Pore water samples were extracted from the minipiezometers for ammonium, nitrate, nitrite and phosphate. Please see “readme.txt” file for further explanation