Studies on the Seeds Dispersal and Seedlings Regeneration in Gaps and Understory of Castanopsis kawakamii Natural Forest

Abstract:

Seed rain and seed bank distribution and seedlings regeneration status in forest gaps and understory of Castanopsis kawakamii natural forest were studied in Fujian Province. The results showed that the amount of total seeds and intact seeds in forest gaps were higher than those in understory, whereas immature seed rate in gaps was lower than that in understory. The falling seed rain at peak stage accounted for 77.13% and 74.5% of total seeds in forest gaps and understory, respectively. Seed reserve in forest gaps was lower than that in understory, which the most in seed bank were totally eaten by animals or picked up seeds in soil seed bank. The seed vertical distribution in soil seed bank was in order as litter layer (about 2/3) > humus layer (about 1/3) > subsoil layer (less than 1%), which dominated by C. kawakamii seeds. The convention rates from seed to seedlings were low in forest gaps and understory. The densities of intact seed and seedlings of C. kawakamii in forest gaps were higher than those in understory. It suggested that the microhabitat of forest gap improved the density and proportion of mature seeds in seeds dispersal and seedlings regenerated. Therefore, forest gaps play important roles in restoration of C. kawakamii population.