高寒草甸退化草地引种适应性

在甘肃省甘南藏族自治州玛曲县境内典型高寒草甸草原区连续两年开展退化草地引种适应性试验。试验期间观测引进草种的物候期、生长发育特征、盖度、地上部分生物量、越冬性能和翌年种子生产状况。结果表明，供试草种在引种当年生长季末均达营养生长阶段，不能结实，草层高度介于4.1～29.6 cm，盖度9%～80%不等;草地早熟禾(Poa pratensis)、高冰草(Agropyron elongatum)和高羊茅(Festuca rundinacea)均不能安全越冬;第2年，越冬牧草能正常完成其生活史，垂穗披碱草(Elymus nutans)、中华羊茅(Festuca sinensis)、冷地早熟禾(P.crymophila)和美国披碱草(Eylmus american)种子能够成熟，其盖度和生物量较第1年大幅度增加;个别牧草能够结籽并成熟。地上部分单位面积产鲜草量:细茎披碱草(Elymustr achycautum)＞扁穗冰草(Agropyron cristatum)＞美国披碱草＞中华羊茅＞无芒雀麦(Bromus inermis)＞冷地早熟禾，且差异显著(P＜0.05)。在玛曲县等黄河源区高寒退化草地，引种披碱草属、羊茅属、早熟禾属、冰草属和雀麦属等多年生优良禾草，可保证其安全越冬建立持久性栽培草地并在建植后的2～3年高产稳产，可用于改良高寒天然退化草甸，发挥防风固沙、防治水土流失的生态效益。

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.