Fig. 1 Dynamics of DBH size class community structure between 2005 and 2010. Diagram (A) shows DBH size class community structures in 2005 and 2010. The empty part of the bar represents the number of individuals of a DBH size class in 2010, the empty plus the grey filled part represent the number of individuals of a DBH size class in 2005, and the grey filled part represents the decrease in number of individuals between 2005 and 2010. (B) shows the change in relative mortality rate with DBH size class. The dotted line divides relative mortality rate values > 1 from values < 1. Values above the dotted line indicate observed mortality rate > expected mortality rate, larger y value represent larger difference; values below the dotted line indicate observed mortality rate < expected mortality rate, smaller y value represent larger difference.

Fig. 2 Comparisons of the biodiversity, number of individuals and area at breast height (ABH) of multiple grain sized assemblages between 2005 and 2010. Box represents the interquartile range and the median (the thick line); the two whiskers up and below the box represent the upper quantile plus 1.5 times interquantile range and the lower quantile minus 1.5 times interquantile range, respectively. Different letters represent significant difference (P < 0.05).

Fig. 3 Rates of change in species abundance, area at breast height (ABH), frequency and importance value (IV) between 2005 and 2010. The right side of the vertical dotted line indicates positive rate of change, the left side indicates negative rate of change.

Fig. 4 Correlations of species abundance, area at breast height (ABH), frequency and importance value (IV) between 2005 and 2010. ○, shade-tolerant species; +, shade-intolerant species. The solid line divides species increased in value from species decreased in value between 2005 and 2010. Values above the solid line indicate increase and below indicate decrease. In (A), on the left side of the dotted line are rare species and on the right side are common species.