Representation of the way the neighbourhood of a tree is updated at the end of a growth step. All the trees in the stand have a list of neighbours. Tree i has three neighbours called 63, 331 and 103 that belong to the stand. Between time t and time t + Δt, the model effects tree growth based on the status of the neighbourhoods at time t. The characteristics of the neighbours are updated after the growth step. Trees 63, 331 and 103 at time t + Δt make it possible to update the neighbourhood of tree i. The new state of the neighbourhoods will be used for the next growth step.