Restrictive regulation of stand density on aboveground biomass allocation and allometric pattern of Oligostachyum lubricum
In order to provide a theoretical basis for establishing a high-productive Oligostachyum lubricum stand, this paper studied the aboveground biomass accumulation, allocation and the allometric pattern of 1 - 3 year-old 0. lubricum at four stand densities (24600 - 29800 stems · hm-2, D1; 37500-42600 stems · hm-2, D2; 46500-52800 stems · hm-2, D3; and 76500-85500 stems · hm-2, D4; with basically the same DBH. The allocation proportion of the 0. lubricum modular biomass was in the order stem>branch>leaf. With the increasing age of the 0. lubricum, the modular biomass and aboveground biomass as well as the leaf/branch, leaf/ stem, and branch/stem ratios at the four stand densities all had an increasing trend, and were significantly higher for 2- and 3-year-old 0. lubricum than for 1-year-old 0. lubricum. The allocation proportion of the branch- and leaf biomass presented an increasing trend, while that of the stem biomass was in adverse. With the increasing stand density, the modular biomass and aboveground biomass of 1-3-year-old 0. lubricum were overall in "∧" shape, i. e., increased gradually at stand densities D1-D3 but decreased significantly at stand density D4. The allocation proportion of the leaf- and branch biomass of 1-3-year-old 0. lubricum decreased, while that of the stem biomass increased. The leaf/branch, leaf/stem, and branch/stem ratios of 1-year-old 0. lubricum were in inverse "N" shape, while those of 2- and 3-year-old decreased on the whole. The leaf-branch biomass accorded with near-constant growth model, and the allometric index decreased slightly with increasing stand density; whereas the leaf-stem biomass and the branch-stem biomass accorded with simple allometric model, and their allometric indices presented a trend of increasing and of decreased after an initial increase with the increase of the stand density, respectively. All the results indicated that when the stand density was higher than 37500-42600 stems · hm-2, more biomass was tended to allocate in stem to promote the longitudinal growth to obtain more light resource, and the suitable stand density for the high-efficient biomass accumulation and allocation was 46500-52800 stems · hm-2.
Oligostachyum lubricumbamboo stand densitybiomass allocationallometric index
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万方数据
维普
