Seed rain and natural regeneration in <Emphasis Type="Italic">Lophostemon confertus</Emphasis> plantations in Hong Kong,China

Natural forests have been increasingly replaced by artificial plantations around the world. Some research results suggest that artificial plantations can promote natural regeneration. The efforts in establishing protective forests in Hong Kong over the last 50 years after the Second World War have resulted in many exotic tree plantations which are ideal sites for the study of natural regeneration. This study looked at the seed rain and understorey woody plant diversity in three Lophostemon confertus plantations (25–40 years old) in Hong Kong. All the plantations were > 1 km from the nearest seed sources. Two of the plantations had a seed rain comparable in density and diversity to unplanted grasslands, and the understorey plant diversity was also low and dominated by shrubs. The other site had a higher and more diverse seed rain, as well as higher understorey stem density, but both the seed rain and the understorey were dominated by the shrub Psychotria asiatica. The poor seed rain at two sites and the rarity of potential canopy tree species in both the seed rain and understory regeneration at all sites suggest that planting exotic monocultures does not promote succession. Enrichment planting will be needed to restore forest diversity.