Changes in stand structure of an old secondary lucidophyllous forest over 21-years monitoring

Abstract

We monitored the stand structure of an old secondary lucidophyllous forest in Takaoka, Miyazaki, southwestern Japan for 21 years (1998–2019). Based on data collected from 10 tree censuses of the 1-ha permanent plot, stem density decreased from 1,532 stems/ha in 1998 to 1,379 stems/ha in 2019. Basal area (BA) increased from 45.74 m²/ha in 1998 to 50.97 m²/ha in 2014, but decreased during the period from 2015 to 2019 because of Castanopsis sieboldii mortality due to a number of typhoon disturbances. The average mortality rate throughout the monitoring period was 1.51%/year, which was higher than the recruitment rate for the same period (1.01%/year). The tree census in 2019 revealed the loss of some small size trees of Quercus salicina and C. sieboldii, which suggests typhoon impacts on the regeneration and species composition of this forest in the near future.