Dynamic Characteristics of Primary Evergreen Broad-leaved Forest in Wulingkeng Mountain, Zhejiang Province

In August 2012, 3 sample plots with area of 100 m×100 m were established in primary evergreen broad-leaved forest in Wulingkeng Mountain, Zhejiang province. Investigations were conducted on species, DBH, height, crown diameter, growth traits of woody plant with DBH ≥ 1 cm, and in 2017, the same investigation was carried out and with dead and new trees. The result demonstrated that 1 277 trees (up to 12.21% of the total ones) died from 2012 to 2017, belonged to 93 species and accounted for 65.49% of the total ones. There had 412 new trees with DBH ≥ 1 cm (3.94% of the total ones), belonged to 50 species (35.92% of the total ones). The number of dead trees had significant exponential negative relation with their diameter classes. The tree species with the highest annual mortality was Symplocos heishanensis (9.27%), while Schima superba had the lowest one (0.52%). The highest number of new tree was Ilex triflora (2.45%), and seven arbor species had no new trees during 2012 to 2017, while shrub had relative higher mortality and replacement rate than arbor species. The growth rate of the basal area of living wood with DBH ≥ 1 cm increased 4.59%, and the average DBH increased 0.55 cm. The growth rate of basal area of living wood with DBH ≥ 5 cm increased 1.04%, and the average DBH increased 0.47 cm. The results indicated that the subtropical primary evergreen broad-leaved forest had higher tree mortality and less new trees, meaning difficult understory regeneration and slow tree growth.