中文摘要：

生物量在地上与地下的分配是植物生长策略的反映,对于研究生态系统碳储量和碳循环有着重要的意义.采用收获法对灌丛群落与物种的地上、地下生物量进行测定,并分析温度和降雨量等气候因素对灌丛群落地上和地下生物量及构成的影响.同时选择三江源地区4种典型的灌丛植物,百里香杜鹃（Rhododendron thymifolium Maxim.）、山生柳（Salix oritrepha Schneid.）、金露梅（Potentilla fruticosa Linn.）和鲜卑花（Sibiraea laevigata（Linn）Maxim.）,进行地上、地下生物量研究.结果显示：三江源灌丛群落的地上生物量介于209.88-3 632.34 g/m2之间,地下生物量介于178.81-2 262.03 g/m2之间,根冠比（R/S）介于0.40-2.57之间;物种的地上生物量介于1.83-3 632.34 g/m2之间,地下生物量介于1.22-2 262.03 g/m2之间,根冠比（R/S）介于0.23-2.63之间.灌丛群落与物种的地上、地下生物量拟合的斜率分别为0.66和0.96,前者与1存在显著性差别,后者与1没有显著性差别.这说明灌丛群落与物种的地上、地下生物量分配分别呈异速分配关系与等速分配关系,百里香杜鹃和鲜卑花的地上与地下生物量分配属于等速分配关系,金露梅和山生柳属于异速分配关系.本研究表明三江源高寒灌丛生物量大小与年均温度的变化关系密切;年均温度与年均降雨量都不能明显地改变根冠比（R/S）.

英文摘要：

Above- and belowground biomass allocation not only reflects plant growth adaptations to environment variations, but also impacts carbon input to the soil and thus terrestrial carbon cycling. Here we investigated biomass allocation patterns of alpine shrubs at both community and species in the Three-iver Source Region, China. Meanwhile, we explored the effects of climate factors （i.e., mean annual temperature, MAT; mean annual precipitation, MAP） on the biomass partitioning pattern. Our results showed that, the aboveground biomass of the community varied from 209.88 to 3 632.34 g/m2, the belowground biomass varied from 178.81 to 2 262.03 g/m2 and the shoot/root ratio （R/S） was 0.40 to 2.57. Among the species, the three biomass variables ranged from 1.83 to 3 632.34 g/m2, 1.22 to 2 262.03 g/m2 and 0.23 to 2.63, respectively. The slopes of the allocation equations were 0.66 and 0.96 for community and species, respectively. These results indicated that the biomass allocation was allometric for community, but the above and belowground biomass scaled isometricly for the species level. Moreover, we examined biomass allocation patterns of four typical alpine shrubs, Rhododendron thymifolium Maxim., Salix oritrepha Schneid., Potentilla fruticosa Linn. and Sibiraea laevigata （Linn.） Maxim. We found isometric above- and belowground biomass of R. thymifolium Maxim. and S. laevigata （Linn.） Maxim., but allometric biomass allocation in P. fruticosa Linn. and S. oritrepha Schneid. Regression analysis demonstrated that the above- and belowground biomass of these alpine shrubs were significantly influenced by MAT, with R/S not related to either MAT or MAP.