不同林龄光皮桦生物量分布初探

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。

Study on Biomass Distribution of Betula luminiferaat Different Ages

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.