中文摘要：

增温可以改变植物的生长,不同植被类型的响应方式有差异.植物根系是植物生产量的重要组成部分,但对其增温响应的研究仍然较少.本研究采用开顶式生长室（OTC）模拟增温的方法,对比了长期增温对青藏高原矮嵩草草甸和金露梅灌丛群落地下生物量和有机碳含量的影响.通过分析不同土层地下生物量的垂直分布、土壤和根系含碳量,发现在长期增温条件下：（1）矮嵩草草甸地下生物量显著减少;（2）2种草甸地下生物量分配明显向深层转移;（3）2种草甸植物根系总碳含量变化不显著,矮嵩草草甸10~30 cm土层根含碳量增加,金露梅灌丛草甸20~30 cm土层的根系碳含量减少;（4）2种草甸土壤总碳含量无显著变化（0~30cm）,但20~30 cm土层矮嵩草草甸土壤有机碳含量增加,金露梅灌丛草甸土壤有机碳含量降低.2种草甸地下资源分配差异将影响全球变暖背景下该地区的植被演替和碳循环.

英文摘要：

Global warming could change plant growth, and there are differences in response among vegetation types. Plant roots are an important part of plant production, but their response to temperature is weak. Using simulated warming with an open-top chamber, we studied the effects of long-term warming on allocations of underground biomass and carbon in a Kobresia humilis meadow and Potentilla fruticosa shrub meadow on the Qinghai-Tibet Plateau. We analyzed vertical distributions of underground biomass, root carbon content, and soil organic carbon content. The results show the following after long-term warming via the open-top chamber： （1） underground biomass of the K. humilis meadow decreased significantly; （2） underground biomass moved to deeper soil layers in both meadows; （3） root carbon contents of underground biomass at 0-30 cm depths did not change significantly in both meadows, but it increased in the alpine K. humilis meadow from 10 to 30 cm and decreased in the P. fruticosa shrub meadow at depths 20-30 cm; （4） soil organic carbon content did not change significantly in the soil layer 0-30 cm, but it increased in the K. humilis meadow and decreased in the P. fruticosa meadow in the 20-30 cm layer. Such differences in resource allocation will impact regional vegetation succession and the carbon cycle under a background of global warming.