Author(s): Rudi Gabrielle; Bailly Jean-Stephane; Belaud Gilles; Vinatier Fabrice
Linked Author(s): Gilles Belaud
Keywords: No Keywords
Abstract: Hydrochorous dispersal plays a major role in the propagation of weeds such as Sorghum halepense. However, the long-distance dispersal of seeds of S. halepense via channels has been poorly studied. We proposed in this experiment to focus on the tail of the seed dispersal kernel obtained after an irrigation event in a vegetated channel. The objective was to understand the main factors implied in transport and deposition of seeds in the channel and to explain the shape of the tail of the dispersal kernel. The results showed that a significant percentage of seeds could travel hundreds of meters during one irrigation event. A Classification and Regression Tree (CART) algorithm was used to classify the importance of the explaining variables in the transport and deposition of seeds along the channel. The model could explain 72% of the variability of the shape of the dispersal kernel. The main factors explaining the shape of the dispersal kernel were the width of the section at the water surface, as well as the cover of emergent vegetation. We also noticed the importance of hydraulic structures such as sluice gates and culverts in the pattern of seed deposition.
Year: 2018