典型草原植物群落根系垂直分布与草原退化阶段的对应变化关系

The Corresponding Relationship between the Vertical Root Distribution of Grassland Communities and Steppe Degradation Stage

以呼伦贝尔草原40个样地的400个地上部分测产数据和200个根系测产数据为基础,探讨典型草原植物群落根系的垂直分布与草原不同退化阶段的对应变化关系,以期为退化草原恢复和预防提供科学依据。结果表明:在不同的退化类型中,不同植物类群所占的比例存在显著差异。高大丛生禾草、小禾草、根茎苔草的生物量随退化程度加重逐渐增多,杂类草逐渐降低,但差异不显著。草原植被根系生物量与退化程度关系密切,退化群落植被根系趋于浅层化,主要集中在0~20cm,并随土层深度增加,根系生物量逐层递减;中轻度退化的草原群落0~20cm土层的相对生物量约大于未退化群落的70%且50~70cm土层显著低于未退化群落,可将其作为草原退化及其恢复治理的关键时期。

Using the data of 40 plots with 400 quadrats for aboveground biomass and 200 quadrats for underground biomass in Hulunbuir steppe,the common regulation of root distribution with plant functional groups and steppe degradation in degraded grassland communities were analyzed.The results showed that：（1）Among the different types of degradation,the proportion of various plant groups was significantly different.Biomass of tall bunch grass,short grass and Carexincreased gradually with the degree of degradation,HDMLDUD;while the Herbs was gradually reduced,but the difference was not significant.（2）The root biomass of grassland vegetation was closely related to the degree of grassland degradation.The root system of the degraded community tends to be shallow,mainly concentrated in 0~20 cm,and with the depth of the soil increased,the root biomass decreased in layer by layer.The relative biomass in 0~20 cm soil layer in mild moderate degradation grassland community was more than 70% of that in no degradation grassland community and the relative biomass in 50~70 cm soil layer was significantly lower than the no degraded grassland,it can be used as a critical period of grassland degradation and restoration administration in this region.