  Forest regeneration is a spatial multifaceted process with numerous unknown
variables. The individual area or the area potentially available (APA) to an
individual plant embodies an idea widely used in population ecology but it has
fewer applications in forest research. It was used a Voronoi/ Thiessen
tessellation in order to determine the individual area of each sapling. The
study was conducted in a naturally regenerated area; using data collected from
over seven thousands saplings positioned in a network of permanent rectangular
sampling plots. The Voronoi/ Thiessen polygons were used to characterize
spatial pattern of sapling distribution as well as the competition relations
between the individuals. It is obvious that, at least from the mathematically
point of view, the Voronoi tessellation represents one of the best solutions to
determine neighbouring competitors of a tree. There were studied the
correlations between APA values and the main biometrical attributes, height
growth and competition indices. Furthermore, it is shown that APA coefficient
of variation is a straight-forward indicator with positive results as an
indicator of spatial pattern. The statistical significance of this indicator
was evaluated by comparing the results with the values of a 95% confidence
envelope generated by Monte-Carlo simulations. Two practical software tools
were produced using Visual Basic (VORONOI and ARIA VORONOI) in order to
simplify the analyses.
