Hydrodynamic behaviour of European black poplar (Populus nigra L.) under coppice management along Mediterranean river ecosystems

This study examined the hydrodynamic behaviour of European black poplar (Populus nigra L.) under coppice management in riparian areas with a multidisciplinary approach. An innovative procedure on the basis of the combination of plant allometric relations and hydrodynamic models was applied to assess drag forces and plant hydrodynamic bending as function of the basal diameter and module of elasticity, with a probabilistic approach. Cuttings of European black poplar from 2 close riverine environments of Southern Italy have been planted and subjected to the same coppice management strategy. The 2 different 3-year-old shoot poplar ensembles exhibited statistically similar morphological traits but stems with different module of elasticity. Drag forces were simulated with a model on the basis of the vegetative Cauchy number. Plant deformation under the hydrodynamic load was modelled as a base-mounted cantilever beam. The differences in the observed elasticity were verified to be also significant from a hydrodynamic perspective. Diagrams were drawn to describe plant bending, drag forces, and basal momentum as function of basal diameter, accounting for the uncertainty in the module of elasticity. These results can be exploited for identifying objective hydrodynamic criteria to be adopted for coppice management of riparian woody vegetation in human controlled river ecosystems.