Original paper

Impact of manual spring harvesting on the regrowth of a spreading aquatic plant: Ranunculus peltatus SCHRANK

Garbey, C. Thiébaut


R. peltatus is a native aquatic plant which is spreading in poorly mineralised waters in the Northern Vosges, NE France. In order to regulate its spread, different dates and frequencies of harvests in spring and summer were tested. Their impact on the biomass, the regrowth strategy of R. peltatus, and the plant community, was evaluated. Harvesting caused a reduction in the biomass of R. peltatus. Two or three harvests did not regulate R. peltatus biomass more efficiently than one harvest. One harvest is most efficient if performed in April or in May, depending on what degree of regulation is wanted. The plant regrew from the pool of roots and seeds developing into new individuals and the branching of existing fragments located in the soil. This regrowth strategy varied according to the frequency and the date of harvest. The rooting capacity of R. peltatus was not impacted. However, its flowering was totally inhibited by the harvests. Furthermore, the harvesting had a very variable effect on the relationship between R. peltatus and E. nuttallii which is an invasive species in this area. Thus, harvesting could be a good tool to reduce the spread of R. peltatus, but it might favour the dominance of another nuisance-causing species, E. nuttallii.


aquatic macrophytesspreading plantsregrowthregulation