Riparian forest structure in a morphologically altered gravel-bed river

The pattern of riparian vegetation in gravel bed rivers depends on the climate, hydrological regime, and the morphological settings of the river. Also, the marked spatial variability of density, height, species diversity, age, and rates of growth reflects the very complex nature of bed colonization, the strong influence of sequences and magnitude of floods, and the feedbacks between morphology, vegetation and hydraulics. Furthermore, a wide array of human impacts acting at either the basin or river network scales can influence substantially the morphodynamics and thus the characteristics, types and distribution of vegetation within the river corridor. The aim of the work is to analyze the relationship between the vegetation structure and the morphological characteristics of two sub-reaches of the Piave river which suffered intense and multiple human impacts especially due to dam building and in-channel gravel mining. The Piave river shows a complex pattern of vegetation distribution along the cross- sections, with no clear relationship between the elevation and the “maturity” of plant communities as a result of a recent tendency of active channel widening after a long period of channel narrowing.