Effects of canopy opening on height and diameter growth in naturally regenerated beech seedlings

In order to analyze the growth dynamics of beech seedlings growing under co ntrasting canopy conditions, a beech stand in which two types of canopy ope ning (canopy release or gap creation) had been applied in 1995 was selected . Three and four years after the canopy had been opened, 113 naturally rege nerated seedlings were sampled in gaps or under the canopy. The effects of canopy opening and seedling age on annual height and diameter growth were a nalyzed using mixed models. Under closed canopy, average annual seedling he ight and diameter increments were 1.2 cm and 0.18 mm, respectively. Diamete r growth increased in the first year after the canopy had been opened, and exhibited considerable inter-annual variation related to climatic condition s. Conversely, height growth did not increase immediately after canopy open ing, but increased regularly in the following years. Four years after the g ap had been created, annual seedling height and diameter growth were 9.5 cm and 0.49 mm respectively in the gaps, and 3.8 cm and 0.21 mm respectively under released canopy. Age did not affect the dynamics of seedling growth.