Abstract: Cyclobalanopsis glauca is a dominant species in the evergreen and deciduous broadleaved mixed forest in Guilin karst mountainous areas. Little information is available about its population status. Here, we analyzed population structure and dynamics of C. glauca by using basic statistics including curves of survival rate, mortality rate, and disappearance rate as well as four survival function curves based on diameter size classes. We performed a time series model to predict the dynamics of C. glauca population in karst ecosystems. The results showed that the age structure was in an inverse-J shape, and mainly aggregated on age class Ⅰ (69.49%). The proportion of individuals successfully colonized in the next age class was very low. The population approximately belonged to the Deevey-Ⅱ  type and grew stably at present stage. Both the mortality and disappearance rate curves exhibited the same trend, with peaks in the first and sixth age classes. The survival rate of the population monotonically decreased, while the cumulative mortality rate increased, and mortality density and risk functional curves of the population varied in a similar trend. The C. glauca population sharply decreased in the young-aged period, stabilized in the middle-aged period, but declined in the old-aged period. The dynamic indices, V_pi and V_pi′, were greater than zero, and showed a stable-growth type population with a little increase butbeing sensitive to external disturbance. Time sequence model suggested that the oldaged individuals would increase in the age-classes of 2, 4, and 6 in the future, and that if the seedlings were not reared in time, the population would be unable to maintain stability.

Key words: Pig manure, Rice straw, Cd-contaminated permeable paddy soil, Biological activity