Water velocity limits the temporal extent of herbivore effects on aquatic plants in a lowland river

摘要: The role of herbivores in regulating aquatic plant dynamics has received growing recognition from researchers and managers. However, the evidence for herbivore impacts on plants is largely based short-term exclosure studies conducted within a single season. Thus, it unclear how long abundance can persist for. We addressed this knowledge gap by testing whether mute swan (Cygnus olor) grazing lowland river macrophytes could be detected following Furthermore, we investigated seasonal changes water current speed limiting temporal extent grazing. found no relationship between biomass density 1 year cover or spring. No such carry-over effects were despite observing high densities previous which inferred macrophytes. Seasonal increases velocity associated with reduced pressure as swans abandoned habitat. our study highlights determining length season shallow rivers thus abundance.