Abstract:

Based on the investigated data of 54 plots of 18 sites in the west coastal area, north plain area, east coastal area and central mountainous area of Hainan Island, the biomass, carbon storage, carbon sequestration and spatial distribution of eucalyptus plantations in Hainan Island, southern China were analyzed. The results indicated that the mean total biomass was 49.72 t·hm^-2, and the biomass distribution of the forest system showed such a sequence as: arbor layer (85.10%)>litters (8.08%)>undergrowth layer (6.82%). The mean total organic carbon storage in the eucalyptus plantation ecosystem amounted to 88.84 t·hm^-2, of which there was 23.13% (20.55 t·hm^-2) stored in the arbor, 1.74% (1.55 t·hm^-2) in undergrowth vegetations, 2.17% (1.93 t·hm^-2) in litters, and 72.96% (64.81 t·hm^-2) in the soil (0-100 cm). The stem had the biggest organic carbon storage of the total carbon storage in various plant organs, accounted for 52.81% of carbon storage in arbor layer. The mean annual net productivity of eucalyptus plantations was 17.56 t·hm^-2a^-1, with a mean annual stored carbon up to 8.43 t·hm^-2, amounted to 30.91 t CO₂·hm^-2a^-1 . The total organic carbon storage and sequestration of the eucalyptus plantations of Hainan Island was 2 958.37×10⁴ t and 280.97×10⁴ t·a^-1, respectively. The carbon sequestration of eucalyptus plantations in the central mountain area (11.89 t·hm^-2a^-1) was largely higher than other three areas, such as the northern plain area (8.97 t·hm^-2a^-1), the western coastal area (7.18 t·hm^-2a^-1) and the eastern coastal area (8.26 t·hm^-2a^-1). The three areas had no significant difference in the carbon sequestration. Except for the western coastal area and the eastern coastal area, the carbon storage among all other areas was significantly different, mainly because of their different carbon storage of soil.

Key words: Eucalyptus urophylla×, E. tereticornis plantation, carbon storage, carbon sequestration, spatial distribution, Hainan Island