Abstract:
Objective Understanding the composition, temporal and spatial dynamics of soil seed bank under natural conditions is important for revealing the mechanism of natural forest regeneration.
Method The seed amount, type, temporal and spatial dynamics of soil seed bank of Dacrydium pierrei in Bawangling, Hainan were observed for 3 years by geostatistics and other methods. The relationship between seed amount, type, temporal and spatial dynamics and environmental factors was analyzed.
Result (1) The proportions of sound seeds, mildewy seeds, hollow seeds, defective seeds in the soil seed bank of Dacrydium pierrei were 0.48%, 45.55%, 29.68%, and 24.30% respectively. (2) The amount of seed followed a reversed 'J' shape curve decreasing relationship with the distance from mother trees. (3) The seed of soil seed bank has obvious spatial pattern. (4) The pattern of vertical distribution of seed amount was litter layer (87.78%) > 0-5 cm layer (11.01%) > 6-10 cm layer (1.2%), the distribution amount showed a sharp decrease in 0-5 cm layer, there was almost no seed to be distributed to the 6-10 cm layer. (5) The amount and ratio of non-viable seeds was higher, reaching up to 100%, the amount of viable seeds was small, the germination rate was as low as 14%, and the seeds lifespan of D. pierrei in the seed bank is less than one year.
Conclusion The characteristics of soil seed banks show it is very difficult for D. pierrei to complete natural regeneration.