【摘要】 对3个不同年龄的光皮桦生物量分布规律的研究结果表明:在2～4年内,光皮桦单株生物量随年龄的增大而迅速增大,表现出良好的速生性,4年生时单株生物量是3年生的238.0%,是2年生生物量的363.4%。从单株生物量的组成来看,干所占比例随年龄增大而增大,从2年生时的45.8%,增加到3年生时的56.4%和4年生的58.2%,枝、叶所占比例则随年龄增加而下降,其中枝的比例从2年生时的26.7%下降到3年生时的20.5%和4年生时的21.6%,叶的比例从2年生时的3.6%下降到3年生时的2.3%和4年生时的2.2%。而不同年龄根系的生物量均表现为主根>侧根>细根。随着林龄的增加,光皮桦单株根冠比在下降,即从2年生时的0.31下降到4年生时的0.22。更多还原

【Abstract】 The biomass distribution of Betula luminifera was studied at different ages,the results showed that: the biomass of Betula luminifera was increased with age,single plant biomass at 4a is 238.0% compared to 3a’,is 363.4% to 2a’.The composition of single plant biomass was different at different ages,The trunk proportion increased with age,which increased from 45.8% at 2a to 56.4% at 3a and 58.2% at 4a,The proportion of branch and leaf decreased by ages,the proportion of branche was 26.7% at 2a decreasd 20.5% at 3a and 21.6% at 4a,the proportion of leaves decreased from 3.6%at 2a to 2.3%,2.2% at 3a,4a respectively.The biomass distribution of root was taproot > root lateral > fine roots at different ages.The ratio of root to shoot decreased from0.31 at 2a to 0.22 at 4a.更多还原