Abstract: A field investigation was conducted at 6 sampling plots in Nan’ao Island of Guangdong Province to study the population structure and dynamic characteristics of Machilus chinensis. In each plot, the diameter at breast height (DBH) (or basal diameter if tree height <1.3 m) and height of each individual were measured. The field data were then analyzed from the aspects of age structure of population, static life table, survival analysis, and time series prediction. In Nan’ao Island, the age structure of M. chinensis population was shaped as an inverse “J”, i.e., more individuals at seedling and sapling stages, and less individuals with mid-size (DBH=8-20 cm) and big size (DBH >20 cm), characterized by a growing population. The survival curve of the population generally matched Deevey type Ⅲ, with the high mortality at seedling stage and lower mortality at big tree stage. The mortality and killing power curves showed similar trend, with one peak at age Ⅰ(seedlings of DBH=0-1 cm) and the other at age Ⅴ(mid-sized trees of DBH=12-16 cm). Age Ⅵ (DBH=16-20 cm) had the lowest mortality and the highest life expectancy. The survival rate of the population decreased monotonically, while the cumulative mortality rate curve increased monotonically. The mortality density and hazard rate curves showed the similar trends to the mortality and killing power curves, i.e., shocked at prophase and metaphase, and stabilized at anaphase. From the age Ⅷ (DBH=24-28 cm), the population gradually entered physiological decline phase. The time series prediction for the population in the coming 2, 5, and 8 years showed that M. chinensis population would have a rising tendency.

Key words: Changhaishan, Wudalianchi, Volcanic ash soil, Zero point of charge, Long-rang tropospheric eolian dust