| Biomass and carbon density characteristics were studied in Masson pine (Pinus massoniana) forests, mixed needle-broadleaved secondary forests and mixed needle-broadleaved artificial forests. The results showed that among the three forest types the maximums of community biomass, arbor layer biomass, grass layer biomass and litter layer weight，were found in the Masson pine forests, the maximum of shrub layer biomass was found in the mixed needle-broadleaved secondary forests, the minimum of biomass in different layers was found in the mixed needle-broadleaved artificial forests. (2) The aboveground biomass was in the order of the Masson pine forests, the mixed needle-broad leaved secondary forestsand the mixed needle-broadleaved artificial forests, whereas the underground biomass was the mixed needle-broadleaved
secondary forests>the Masson pine forests > the mixed needle-broadleaved artificial forests. The highest ratio of root to，stem was found in the mixed needle-broadleaved secondary forests, which was 0.27(依0.01). (3) The Masson pine forests had，the highet carbon density with an value of 79.71（×16.92）t/hm2 the mixed needle-broadleaved secondary forests occupied second with a value of 64.46 （×12.61）t/hm2 and the mixed needle-broadleaved artificial forests had the lowest carbon density, which was 59.62（×15.22）t/hm2. (4) The ratio of arbor layer carbon density to community carbon density was in the
order of the Masson pine forests, the mixed needle-broadleaved artificial forests, the mixed needle-broadleaved secondary forests. |
