Riverine large woody debris introduced for natural flood management leads to rapid improvement in aquatic macroinvertebrate diversity

Natural flood management interventions, such as Large Wood Debris (LWD) or engineered log jams, are being increasingly deployed throughout the UK and elsewhere. In addition to alleviating risk, it is anticipated that they may influence ecology of freshwater river systems, including macroinvertebrate populations. This study explores assemblages, water quality parameters, sediment size distribution in a headwater stream following LWD part natural scheme. The area consists 6 sites within intervention zone where jams were implemented, with comparative control upstream downstream (3 each). Macroinvertebrate communities, distribution, chemistry sampled 3 10 months LWD. Our findings revealed increased abundance taxa richness versus control, an BMWP score reflecting richness. Average Score Per Taxon, showed no change, revealing invertebrate changes be independent quality. NMDS hierarchical clustering analysis on data clear separation communities was present from those LWD, while SIMPER led rapid establishment (Hydraenidae, Rhyacophilidae, Scirtidae, Elmidae) otherwise absent. Ten after addition, improved biodiversity also found areas below zone, suggesting positive impacts extend downstream. altered sediments, immediately having greater percentage fine than These results suggest biological complexity niche availability in-channel result introduced thus wider aquatic habitat improvement potential for management. use recommended its additional benefits ecosystem health.