Seminário CEF/CEABN: Ecologia, Florestas e Conservação

O próximo seminário CEF/CEABN "Ecologia, Florestas e Conservação" ocorrerá ONLINE no dia 24 de Novembro, entre as 12h30m e as 13h30m, com o título: 
"Restoration of biogeomorphological processes in low energy systems: the example of the Sélune river, France"
por Paul VRCHOVSKY, Université Rennes 2, França

Resumo: The removal of dams leads to significant changes in river landscapes. It is therefore an exceptional opportunity to observe a wide range of adjustments and to characterize the relative share of abiotic and biotic processes in the dynamics of river systems. Indeed, the respective weights of the factors controlling biogeormorphological adjustments of rivers are still in exploration for a large number of geographical contexts (urban rivers, moderate energy rivers, etc.). The objective of this presentation is the quantification of the weight of hydraulic and biological factors in the current shape of lowland and plateau rivers. Taking as a case study the restoration of the Sélune valley (Normandy, France), two types of biogeomorphological interactions are targeted (zoogeomorphological (1) and phytogeomorphological (2) interactions). Thus, the first results, obtained by sediment tracing and micro-topographic monitoring, show, in a quantitative way, the morphogenicpotential of an aquatic amphihaline species: the sea lamprey (Petromyzon marinus). In order to reproduce (spring/summer season), this species modifies locally the micro-topography of the channel bed in a sensitive way by mobilizing the coarse materials of the substrate (bioturbation process). The intensity and duration of this modification is being monitored to understand how it interacts with winter hydromorphological processes (e.g. bedload movement), thus questioning potential feedbacks in the river landscape.  

Nota biográfica: Paul is currently 26 years old and he is a 3rd year PhD student. He has studied environmental geography, with a Master degree specialized in remote sensing applied to continental ecosystems. His experience in fluvial systems has started with volunteer fieldworks for hydromorphologicpurposes. He continued during his Master’s internship where he applied deep learning methods for river’s morphological features detection in Normandy streams. Then, he pursued with a PhD degree about biogeomorphological interactions in the Sélune river, Normandy.