中度与重度退化针茅型高寒草地群落比较研究

通过对青海湖北岸三角城种羊场地区中度与重度退化高寒草地群落的比较研究。结果表明:随着草地退化程度的加重,草地群落的盖度、物种多样性指数、均匀度指数均下降,草地生物量的积累速率减弱,最终导致了草地初级生产力的降低,杂类草增多,优良的禾本科牧草在草群中所占的比例下降,枯落物的季节变化速率在6~7月份表现为分解速率,中度退化样地>重度退化样地;8~9月份表现为积累速率,中度退化样地<重度退化样地。

Comparative research on the plant communities of moderate-degraded and heavy-degraded stipa alpine grassland

A study was conducted at the Sanjiaocheng sheep breeding farm of Qinghai province,which is located on the north bank of Qinghai Lake with natural alpine grassland.A comparative research on the plant communities between moderate-degraded and heavy-degraded alpine grassland was conducted,the result showed that with the aggravation of grassland degradation,the coverage,species diversity indexes,evenness indexes of plant communities decreased.The accumulative rate of biomass of plant communities decreaed,leading to primary production decreased.The percentage of fine forages such as grasses decreased with the increasing of forbs.The seasonal change rate of litter appearedas decomposing rate from June to July,and as accumulative rate from August to September.The decomposing rate of moderate-degraded plots was more than heavy-degraded plots and the accumulative rate of moderate-deqraded plots was less than heavy-degraded plots.