Action: Crassula helmsii: Dry out waterbodies to control plants
- We found no evidence for the effects of draining waterbodies on Crassula helmsii.
'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.
Draining waterbodies is a potential tool for eliminating or reducing invasive aquatic organisms. One pond infested with C. helmsii was reported to have been drained over winter resulting in a reported ‘severely reduced biomass’ of the plant, although no data were provided (Dawson & Warman 1987). The ability of C. helmsii to withstand drying out (Anderson et al. 2015) and regenerate from small fragments of plant material (Dawson & Warman 1987) mean that this approach alone is unlikely to be fully effective. It is also likely to have negative impacts on native species.
Anderson L.G., Dunn A.M., Rosewarne P.J. & Stebbing P.D. (2015) Invaders in hot water: a simple decontamination method to prevent the accidental spread of aquatic invasive non-native species. Biological Invasions, 17, 2287-2297.
Dawson F. H. & Warman E.A. (1987) Crassula helmsii (T. Kirk) Cockayne: Is it an aggressive alien aquatic plant in Britain? Biological Conservation, 42, 247-272.