Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 1 3 1997 10.5194/hess-1-499-1997 http://www.hydrol-earth-syst-sci.net/1/499/1997/ http://www.hydrol-earth-syst-sci.net/1/499/1997/hess-1-499-1997.html http://www.hydrol-earth-syst-sci.net/1/499/1997/hess-1-499-1997.pdf 499 508 0000-00-00 Fluvial sediment inputs to upland gravel bed rivers draining forested catchments: potential ecological impacts S. D. Marks G. P. Rutt Institute of Hydrology, Plynlimon, Staylittle, Llanbrynmair, Powys, SY19 7DB Environment Agency, Welsh Region, Penyfai House, 19 Penyfai Lane, Furnace, Llanelli, Dyfed, SA15 4EL As identified by the detailed long-term monitoring networks at Plynlimon, increased sediment supply to upland fluvial systems is often associated with forestry land-use and practice. Literature is reviewed, in the light of recent results from Plynlimon sediment studies, to enable identification of the potential ecological impacts of fluvial particulate inputs to upland gravel bed rivers draining forested catchments similar to the headwaters of the River Severn. Both sediment transport and deposition can have significant impacts upon aquatic vertebrates, invertebrates and plants.