Colonisation of alluvial banks by black poplar seedlings: how intra-specific interactions shape the spatial genetic structure

International audiencePopulus nigra L. (Salicaceae) seedlings grow in high densities in stressful environment. Individual plants interact mostly with their direct neighbors. Spatial genetic structure (SGS) indicates the presence of related individuals close to each other. Thus, SGS pattern can influence what type of biotic interaction (positive or negative, see Fig1) will take place among immediate neighbors (i.e. within the zone of interaction). Moreover, intra-specific interactions can change with stress intensity. Studying SGS at a scale including the zone of interaction (ZOI) between plants allows to allows us to explore the type of interaction occurring between individuals. The evolution of SGS is closely linked with intraspecific interactions, which also dependent on the stress level. A change in the type of interaction can lead to the emergence or loss of SGS. The study of FSGS through time from dispersion to mature stands can be a valuable tool to understand and monitor intra-specific interactions. Cohort monitoring approach from establishment to the mature stage appears to be promising for understanding how riparian successions unfold and guide managements actions