黄河源区藏嵩草沼泽化草甸地上生物量及营养季节动态研究

采用野外调查和室内分析方法，对黄河源区广泛分布的藏嵩草Kobresia tibetica沼泽化草甸在禁牧封育和自由放牧利用状态下的草地地上生物量和营养的季节动态进行分析。结果表明：禁牧封育草甸和放牧草甸从8月-翌年4月地上生物量均呈下降趋势，其自然损失率分别为46.2%和49.6%。封育草甸的生产力1-4月、4-5月的自然损失率分别为5.1%和5.9%；草甸进入放牧利用后，放牧草甸牧草相对于封育草甸牧草的实际利用量约占4月草地地上现存量的48.4%，约占8月草地地上生物量的24.4%。放牧草甸牧草营养成分从8月到翌年1月粗蛋白、粗脂肪含量降低，粗纤维含量增加。该草甸在夏季属“氮碳”（NC）营养型,在冬季属“碳”（C）营养型。

Seasonal dynamics of aboveground biomass and nutrients of Kobresia tibetica meadow in Yellow River headwater area

Seasonal nutrition dynamics of fenced and grazed Kobresia tibetica meadow in Yellow River headwater source were studied with methods of field investigation and lab analysis.The result showed that the total biomass of grazed and fenced meadow decreased from August to the next April and the natural biomass loss were 46.2% and 49.6% respectively.The natural loss rates were 5.1% from January to April and 5.9% from April to May in fenced grassland.After grazing,the factual utilization rate of grazed grassland wa...