Abstract:

Based on a survey of 104 sample plots, totally 94 sample trees were harvested and measured. Regression models between tree biomass with DHB and height of 7 main species were established to estimate the allocation of biomass and net primary productivity of the main vegetations in Three Gorges Reservoir Region. The results showed that: 1) Allocation of biomass to trunks was the greatest in all measured species, and it made up 44.46%～63.07%，however allocation of biomass to barks，branches，leaves and roots were varied with different species; 2) There was a significant linear negative correlation between the percent allocation of biomass to trunks and branches，and between trunks or leaves，while a positive correlation was found branches and leaves. The percent allocation of biomass to trunks and barks of conifers increased with the total tree biomass increasing，whereas the percent allocation of biomass to branches，leaves and roots declined; 3) The biomass of different stands were estimated to be between 75.38～191.82 t·hm^-2 with tree layer(67.57～179.0 0 t·hm^-2)>litter layer(2.40～8.35 t·hm^-2)>shrub layer(3.95～11.61 t·hm^-2). Relative lower biomass of tree layer and litter layer benefited the growth of shrub layer; 4) NPP of different stands were 4.78～11.07 t·hm^-2a^－1. Evergreen broadleaved forests were the highest of NPP ，while Cupressus funebris forests were the lowest. Mix forests were higher than pure forests，and coniferousdeciduous mixed forests were higher than coniferous mixed forests.

Key words: Three Gorges Reservoir Region, biomass, productivity, regression models, allocation