不同恢复措施对西藏安多高寒退化草地植被的影响

为探讨不同恢复措施条件对草地植被特征、地下生物量、地下种子库以及多样性等方面的影响,在西藏安多典型退化草地进行围栏,并选用细茎冰草(Agpoyron trachyeaulun L.)、垂穗披碱草(Elymus nutans Griseb)、无芒雀麦(Bromus inermis Layss)和冷地早熟禾(Poa crymophila Keng)4种牧草,在围栏内进行免耕补播的试验研究。结果表明:经过免耕补播和围栏封育后,草地植物高度、盖度、产量均有不同程度的提高;植物多样性有少量增加,植被优势种差异较显著;植物群落地下生物量变化幅度较大,特别是经过围栏和补播的草地,其0~10 cm地下生物量增加明显;此外,土壤种子库测定表明,围栏和补播试验地种子总数明显高于围栏外,增加的种子数主要分布在0~5 cm的土层中。

Effects of Restoration Measures on Vegetation Features of Alpine Degraded Grassland of Amdo County in Tibet

Agpoyron trachyeaulun L.,Elymus nutans Griseb,Bromus inermis Layss and Poa crymophila Keng were reseeded in fenced areas using no-tillage.Vegetation height,coverage and grass yield were studied in order to reveal the effects of different restoration measures for vegetation characters,underground biomass,seed bank and diversity of Amdo in a typical degraded meadow in Tibet.Results showed that vegetation height,coverage and grass yield improved after no-tillage reseeded and fenced.Plant diversities increased slightly while there were significant differences among dominant species.Further,changes were seen in underground biomass of plant communities.Biomass of 0~10 cm soil layer ascended dramatically after fenced and reseeded.Additionally,the numbers of seeds in both fenced and reseeded plots were greater outside the fence and distributed mainly within 0~5 cm soil layer.