Adaptability of introduced species for improvement of degraded alpine grassland in Gannan areas, China

Two consecutive years of reseeded and improvement trial for degraded grassland were conducted in alpine pasture in Maqu county Gannan prefecture,Gansu province.During the experiment time,phenotypic,growth characteristics,coverage,above-ground biomass,characteristics of winter hardy and seed set performance of introduced species in the next year were determined and measured.In the first year of re-sowing,all the tested species were in the vegetative stage and can not have seeds,the height of the reseeded pasture varied from 4 to 29 cm,the coverage scoped 9%-80%,the species of Poa pratensis,Agropyron cristatum and Festuca arundinacea have difficulties in winter hardy.In the second year,the winter hardy species developed into the reproductive stage,Elymus nutans,Festuca cinensis,Poa pratensis,E.sibiricus,and E.america were matured.The coverage and above-ground biomass of the winter hardy species increased in great margins,the data available lay a strong found for improvement of degrade grassland in the alpine area,and offer scientific base for introduction of forage species adapted to this adverse conditions.