Effects of surface disturbance and light level on seedling emergence in a Japanese secondary deciduous forest

The effects of soil surface disturbance and Light level on seedling emergence were examined by creating experimental conditions differing in soil surface treatment and light level in a temperate deciduous broadleaved secondary forest in central Japan. The results of MANOVA showed that soil surface disturbance exerted a favourable influence upon the seedling emergence of many species. Effect of soil disturbance on total density and number of emerged species was greater than that of a high light level. The interaction between soil surface disturbance and light level revealed significant positive effects for seedling emergence, especially for small-seeded species. The relationship between the percentage of emerged seedlings and seed weight was significantly negative in the soil-surface disturbed and high light level condition, suggesting that minute-seeded species largely depend on both factors for seedling emergence. Both soil surface disturbance and high light level had a positive effect on the number of emerged species, suggesting that these factors contributed to species richness at the stage of seedling emergence.