格姆滩黑土滩人工草地植物量及营养季节动态研究

对地处三江源区“黑土型”退化草地上建植的垂穗披碱草7龄人工草地，从8月到翌年的4月进行了地上植物量及营养成分季节动态的研究。结果表明：在人工调控管理下，人工草地的群落组成仍然以垂穗披碱草为优势建群种。从8月到10月、10月到翌年的4月、8月到翌年的4月封育草地地上植物量分别损失了6。7％、32。8％、37．3％，植被盖度分别下降了5．6％、11。8％、16．7％，放牧草地地上植物量分别损失了6．7％、83．5％、84．6％，植被盖度分别下降了5．6％、35．3％、38.9％。草地的实际利用率为47。4％。从8月到翌年的4月粗蛋白、粗脂肪、磷均呈下降趋势，粗灰分、粗纤维、无氮浸出物均呈上升趋势，营养物质总量损失了3．51％。在夏季该草地属碳氮营养型（CN），冬季属碳营养型（C）。

Seasonal dynamics of biomass and nutrition of artificial grassland established in "black soil type" degraded grassland in Gemutan

Seasonal dynamics of biomass and nutrition of artificial grassland established in ＂black soil type＂ degraded grassland in Gemutan were in vestrgeeted. The result showed that under artificial control, the dominant species was still Elymus nutance in the artificial grassland community. From Aug. to Oct, Oct.to Apr. and Aug. to Apr. the natural less rates of aboveground biomass were 6.7%, 32.8%, 37.3% ,and vegetation coverage decreased 5.6%, 11.8%, 16.7% in livestock excluded pasture. In grazing pasture, the natural less rates of aboveground biomass were 6.7 %, 83.5%, 84.6 %, and vegetation coverage decreased 5.6% ,35.3% ,38.9% .The actual utilization rate was 47.4%. From Aug. to the next year Apr. The content of crude protein, crude fat, P were decreased obviously and the crude fibre,nitrogen-free, crude ash were increased, the loss rate of total nutrition was 3.51%. The artificial grassland belong to ＂CN＂ nutritive type in summer, and ＂C＂ nutritive type in winter.