鼎湖山南亚热带常绿阔叶林荷木种群动态变化.

Schima superba is a dominant species in the lower subtropical evergreen broad-leaved forest community at Dinghushan. In order to understand the construction mechanism of lower subtropical evergreen broad-leaved forest community, we have established a 20 hm2 forest biodiversity monitoring plot at Dinghushan National Nature Reserve. The data presented in this paper are based on four field investigations of all S. superba individuals from 2005 to 2017. We further analyzed the distribution characteristics of its death rate according to diameter class and habitat type. The results were as follows:(1)The number of S. superba individuals was largely reduced from 2005 to 2017.(2)Mortality rate and growth rate of S. superba showed different patterns depending on diameter class. The relative growth rate of the individuals of 1-10 cm DBH was high and rapidly decreased, while the mortality rate increased and maintained at a high level. With the increase of DBH class, the relative growth rate of the individuals of 10-50 cm DBH rose and decelerated, and then decreased, while the mortality rate decreased. The mortality rate of those individuals above 50 cm DBH was large while the growth rate was little.(3)The mortality rate of the individuals in each habitat in 2010 was not apparently different. However, in 2015, the mortality rate of individuals in high-altitude habitats(high slopes, ridges, and valleys)was greater than those in low-altitude habitats(low slopes and valleys), while those in low-altitude habitats in 2017 were higher than those in the high-altitude habitats.(4)The mortality rate was significantly positively correlated with soil pH and negatively correlated with soil organic matter, total nitrogen, total phosphorus, available potassium, and available nitrogen content. [ABSTRACT FROM AUTHOR]