Seedling establishment of Fagus engleriana ,a dominant in mountain deciduous forests
山地落叶阔叶林优势树种米心水青冈幼苗的定居

The survival and growth of Fagus engleriana seedlings in three light levels,and with and without supplying additional fertilizer (F 1 and F 0, respectively) for each light level were studied. The three light levels were to simulate the light regimes in the understorey, small gaps and clearings (L 1, L 2 and L 3 about 1%, 18% and 100% of full sunlight, respectively).The seedling development in L 1 was severely inhibited by low light intensity. Seedling mortality was remarkably higher in L 1 than in L 2 and L 3, and in F 1 than in F 0. The death of the seedlings seemed to result from attack of fungal pathogens. Although seedling survival and growth were significantly improved as light intensities increased from L 1 to L 2, seedlings in L 3 developed similarly as those in L 2. It is suggested that the young seedlings could not tolerate the shade of closed forest canopy, and fertile patches on the forest floor might not improve seedling establishment.Successful regeneration of the species in the forests needs better light conditions such as those in gaps than those under the closed forest canopy, at least during the phase of seedling establishment.