Abstract: In order to screen out the perennial grasses suitable for planting in the degraded grassland of the “Black soil hill” in the Three Rivers Headwaters region,five species of were planted on the sunny and shade slopes of Wosai Township,Dari County in 2019. A randomized block experiment design was used to study and comprehensively evaluate the adaptability and production performance of different grasses on the sunny and shade slopes. The results showed that:All the five species were able to safely overwinter on both sunny and shady slopes and complete the growth period to ripen the seeds. For different grass species in the same slope orientation,aboveground biomass of Elymus breviaristatus ‘Tongde’ on sunny slope and Elymus tangutorum on shady slope was the highest with 908.88 g·m^-2 and 979.03 g·m^-2,respectively. When the same grass grows in different slopes,the aboveground biomass of E. breviaristatus ‘Tongde’ in the sunny slope was higher of 362.39 g·m^-2 compared to that in the shady slope;the seed yield of Elymus sibiricus ‘Tongde’ in the sunny slope increased by 104.07 g·m^-2 compared to that in the shady slope. The height,aboveground biomass,underground biomass,seed yield and 1 000-grain weight were evaluated by fuzzy mathematical membership function. E. breviaristatus ‘Tongde’ and E. tangutorumon in the sunny slope and Elymus nutans and E. sibiricus ‘Tongde’ in the shady slope had a better growth performance and higher comprehensive value. Therefore,they were suitable to be popularized and planted in the degraded grassland in “black soil hill” in Sanjiangyuan region.

Key words: The Three Rivers Headwaters region, "Black soil hill" degraded grassland, Slope orientation, Elymus spp., Membership function method

摘要： 为筛选出适宜三江源区“黑土山”退化草地种植的多年生牧草，于2019年在达日县窝赛乡直却沟阳坡和阴坡种植5种披碱草属牧草，采用随机区组试验设计，对阳坡和阴坡不同披碱草属牧草的适应性、生产性能进行研究与综合评价。结果表明：阳坡和阴坡5种披碱草属牧草均能安全越冬并完成生育期收获种子；同一坡向不同草种，阳坡‘同德’短芒披碱草（Elymus breviaristatus‘Tongde’）、阴坡麦宾草（Elymus tangutorum）的地上生物量最多，分别高达908.88 g·m^-2和979.03 g·m^-2；不同坡向同一草种，阳坡‘同德’短芒披碱草的地上生物量较阴坡增加了362.39 g·m^-2；阳坡‘同德’老芒麦（Elymus sibiricus ‘Tongde’）的种子产量较阴坡增加104.07 g·m^-2。将牧草高度、地上生物量、地下生物量、种子产量、千粒重用隶属函数法综合评价得出，阳坡‘同德’短芒披碱草和麦宾草，阴坡垂穗披碱草（Elymus nutans）和‘同德’老芒麦长势较好，综合价值较高，适宜在三江源区“黑土山”退化草地推广种植。

关键词: 三江源区, "黑土山"退化草地, 坡向, 披碱草属, 隶属函数法