Carbon stock of the ecosystem of lower subtropical broadleaved evergreen forests of different ages in pearl river delta,China

This research analysed the carbon stocks and distribution characteristics of the ecosystems of lower subtropical broadleaved evergreen forests of different ages (young,middle-aged and mature) in the pearl river delta. forest age significantly affected carbon stocks of a forest ecosystem. carbon stocks ranged from 125.23 to 125.23 t c ha-1 in the forest ecosystem,40.17 to 154.05 t c ha-1 in the arbor layer and 72.12 to 105.73 t c ha -1 in the soil. secondary biomass carbon was an important carbon pool,which accounted for about 7-10% of the ecosystem carbon stock with ranges from 12.94 to 22.18 t c ha-1. ecosystems with different forest ages showed significant differences in carbon stock distribution characteristics. the soil contributed 56.55% carbon stock to young forests; arbor layer and secondary biomass contributed less with 31.50 and 10.33% respectively. however,in middle-aged and mature forests,the arbor layer contributed the most carbon stock. soil and secondary biomass contributed less. in the secondary biomass stock,understorey vegetation provided the most carbon stock for young and middle-aged forests with 61.51 and 55.36% respectively. coarse woody debris provided the most carbon stock (51.26%) for mature forests. © forest research institute malaysia.