*2.1. Study Area*

The study area was located in the Dinghushan Mountain (112◦30 39"–112◦33 41" E, 23◦09 21"–23◦11 30" N) in Guangdong Province(The map in reference [20]). Dinghushan was the first Nature Reserve established in China in 1956. The reserve is covered by tropical-subtropical forests and comprised of low mountains and hilly landscapes. Dinghushan has a south subtropical monsoon climate with a mean annual temperature of 20.9 ◦C. Annual mean precipitation is 1929 mm with most of the precipitation occurring between April and September. Annual evaporation is 1115 mm and relative humidity averages 82% [21].

A permanent 20 ha (400 m × 500 m) plot called the DHS Plot was established in the Dinghushan reserve in November 2004. Investigating and mapping of trees was completed in October 2005. Field protocols followed that of the Center for Tropical Forest Science (CTFS) with all free standing trees and shrubs of ≥1 cm in diameter at breast height (DBH) identified, measured for height and diameter, and their location mapped [22,23]. The plot is characterized as having rough terrain with a steep hillside in the southeast corner. Topography varies between ridges and valleys with elevation ranging from 240 to 470 m *a.s.l*. In total, 71,457 individuals were mapped in the 20 ha plot. Thirty species were composed of singletons, while 110 species had fewer than 20 individuals [24].
