Abstract:

Using the methods of field plot investigation and sample tree plot harvesting, biomass in 18 plots of Quercus aquifolioides shrub communities, distributing along altitudes from 2 720 m to 3 120 m, studied at Balangshan Mountain in Wolong Nature Reserve. The results showed: 1) The preferred model, which estimate the organs' biomass of individual with diameter (D) or height (H), was an exponential model or a power function model, and the latter was the best with relative coefficients ranging from 0.941 to 0.998; the preferred model, which estimate the organs' biomass of individual with D²H, was a linear model or an exponential model, and the former was the best with relative coefficients ranging from 0.982 to 0.996; 2) The average total biomass of Q. aquifolioides shrub community was 25.22 t·hm^-2, the biomasses in different layers were Q. aquifolioides layer > ground litter > the associated shrubs layer > moss> herbage, and their biomasses accounted for 72.20%,23.71%,1.80%,1.66% and 0.63% of the total biomass respectively; 3) The total average biomass of Q. aquifolioides population was 18.21 t·hm^-2, the biomasses in different organs were stem > branch > leaf > bark, and their biomasses accounted for 43.28%,26.88%,19.82% and 10.02% of the total population biomass respectively. For the aboveground biomass of the populations distribute from 2 720 m to 2 920 m, stem∶branch∶leaf∶bark was 4∶3∶2∶1; and for the aboveground biomass of the populations distribute from 3 020 m to 3 120 m, stem∶branch∶leaf∶bole bark was 4∶2∶2∶1; 4) There was a decline trend in base diameter, height, and biomass of Q. aquifolioides with the increase of altitude. Aboveground biomass of individual was spindle distribution for the Q. aquifolioides from 2 720 m to 2 920 m, and it distributed mainly from 2.0 m to 3.0 m of the stem, accounted for 60%～70%; for the Q. aquifolioides from 3 020 m to 3 120 m or in drought habitats in lower altitude area, aboveground biomass of individual was pyramid distribution, it increased with the height of the tree, it distributed mainly from 0.0 m to 1.0 m of the stem, accounted for 62%～83%, and the biomass from 0 m to 2.0 m of the stem accounted for 94%～99%.

Key words: Quercus aquifolioides, aboveground biomass, model, altitudinal gradient, Wolong Natural Reserve