The drag and reconfiguration experienced by five macrophytes from a lowland river
O'Hare, Matthew T.; Hutchinson, Kathryn A.; Clarke, Ralph T.. 2007 The drag and reconfiguration experienced by five macrophytes from a lowland river. Aquatic Botany, 86 (3). 253-259. 10.1016/j.aquabot.2006.11.004Full text not available from this repository.
Drag and flexibility of five macrophytes (fresh mass 3 g) collected from the same river were measured at velocities from 0 to 0.5 m s-1 in a flume. Drag increased with increasing velocity for all five species examined. Sparganium emersum Rehmann, which has simple strap-like leaves experienced significantly less drag than the other, bushier species whilst there was no significant difference between the drag on Callitriche stagnalis Scop., Ranunculus penicillatus pseudofluitans (Syme) S.D. Webster, and Myriophyllum spicatum L. above 0.4 m s-1. Potamogeton x zizii W.D.J. Koch ex Roth, which has large flat leaves, experienced significantly higher drag than all the other species. All the plants were very flexible but flexibility (as angle of bend) did not explain the drag experienced by the plants, e.g. S. emersum was the least flexible. The plants also changed shape and compressed (reconfigured) under increasing water velocity which reduced the rate at which drag increased. Reconfiguration capacity was assessed as E-values. There were no significant differences in E-values between species indicating that all the samples examined had a similar capacity to reconfigure. It is concluded that measurement of the drag experienced by plants is useful and may prove helpful in explaining the distribution of macrophytes in rivers.
|Programmes:||CEH Programmes pre-2009 publications > Water|
|CEH Sections:||_ River Ecology|
|Additional Keywords:||drag, reconfiguration, Ranunculus, Callitriche, Sparganium, Potamogeton, Myriophyllum|
|NORA Subject Terms:||Botany
Biology and Microbiology
|Date made live:||25 Jan 2008 14:23|
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