Abstract:

Background and Aims Evergreen broadleaved forest is an important vegetation type in National Nature Reserve of Tianmu Mountain, Zhejiang Province. Study of dominant plant populations and their spatial patterns can reveal the roles of these populations and provide a theoretical basis for forest protection and restoration.

Methods A typical plot of 100 m×100 m was surveyed and dominance index analysis was applied to determine dominant plant populations. Ripley'sK(d) function was applied to diagnose spatial patterns and spatial associations between species pairs.

Key Results The number of dominant tree species increases with size class, but the degree of aggregation decreases. The evergreen shrub Camellia fraterna dominates seedling and small-tree size class. Cyclobalanopsis gracilis, Cyclobalanopsis glauca and Lithocarpus brevicaudatus dominate mid- and large-tree classes and have structural characteristics of multi-dominant tree species. Camellia fraterna, Cyclobalanopsis gracilis and Cyclobalanopsis glauca have stable and significant aggregated spatial patterns. Spatial patterns of Litsea coreana var. sinensis and Lithocarpus brevicaudatus vary greatly. In general, the five dominant populations have aggregated distributions. Camellia fraterna and Cyclobalanopsis gracilis or Lithocarpus brevicaudatus or Litsea coreana var. sinensis, Cyclobalanopsis gracilis and Lithocarpus brevicaudatus, and Cyclobalanopsis glauca and Litsea coreana var. sinensis, are significantly spatially independent of each other. Cyclobalanopsis glauca and Lithocarpus brevicaudatus are negatively associated with each other, so are Cyclobalanopsis gracilis and Cyclobalanopsis glauca. The association between species pairs is transferable, in that the association of the third species pairs can be deduced from the known association of two species pairs in three species; the more significant the association of species pairs and the wider the distance scale, the more stable the transference is.

Conclusions The dominant evergreen broadleaved tree species in Tianmu Mountain National Nature Reserve are significantly aggregated, and most are strongly associated.

Key words: Evergreen broadleaved forest, Dominance index, Dominant species, Spatial pattern, Ripley's K(d) function