[Biomass of Quercus fabri population under different ecological restoration regimes in subtropical China]

In this paper, the tissue-specific biomass and above-ground biomass of Quercus fabri under different ecological restoration regimes in subtropical China were analyzed by establishing allometric models with different parameters. The best-fitted equations were adopted for estimating the biomass and its annual growth, and the below-ground biomass and its increment were estimated on the basis of its linear relationship with above-ground biomass. The results showed that the biomass of the branches and of the total above-ground tissues was best described by power-function models, and the best fitted independent variables were d2l and D2H, respectively. The tissue-specific biomass and total biomass of Q. fabri population were all greater in secondary forest than in Pinus elliottii plantation. The above-ground biomass and below-ground biomass of Q. fabri population in secondary forest were 3.592 and 1.723 t x hm(-2), respectively, in which, different tissue components were ranked in the order of stem > branch > leaf; while those in P. elliottii plantation were 0.666 and 0.462 t x hm(-2), respectively, in which, different tissue components were ranked in the order of stem > leaf > branch. From 2004 to 2006, the annual increments of above-ground, below-ground, and total biomass increased with time, and the increment of above-ground biomass had an ascent tendency, which was from 54.35% to 62.20% in P. elliottii plantation and from 67.27% to 68.94% in secondary forest. In comparing with that in secondary forest, the biomass increment of Q. fabri population in P. elliottii plantation was small, despite its relatively high growth rate.