Stand dynamics in Fontainebleau; dynamics in beech forest structure and composition over 17 years in La Tillaie forest reserve, Fontainebleau, France

Developments in forest structure and composition were studied over a 17 year period in a near-natural beech forests reserve in Fontainebleau, France. In two 1ha plots, all individuals with a dbh > 5cm were mapped, identified and measured in 1983, 1990 and 2000. Individual growth was highly variable between periods, and a large proportion of individuals survived one or both periods with no detectable change in size. Generally, mortality is relatively high. A shift from clumped establishment towards hyperdispersion in large trees was detected. Dead wood levels vary in space and time but are relatively high, compared to other studies. Two regeneration pathways are distinghuised. Firstly, gap phase regeneration, with estblishment in groups and higher survival in dominant individuals. Secondly a substantial proportion of individuals shows strong survival with no detectable change in size and flexible growth patterns. Two major factors are identified in influencing forest development in Fontainebleau. Firstly a dynamic cycle based on forest history, with wave like regeneration waves, slowly leveling of in time. Secondly a shorter storm initiated cycle, creating gaps and opportunities for regeneration and supressed individuals. The combination of forest history, tree behaviour and unpredictable occurences of storms results in complex forest dynamic