放牧对短花针茅荒漠草原草群氮贮量分配及动态的影响

Effects of Grazing on Distribution and Dynamics of Nitrogen Reserve of Stipa breviflora Desert Steppe Communities.

在封育和轮牧条件下，研究了氮在短花针茅荒漠草原草群地上与地下、鲜草、立枯草以及短花针茅、冷蒿等各类群中的分配及季节动态规律。结果表明，在此生态系统中，草群中贮氮主要分配于地下部分，放牧可加大地下部分的分配比例，同时也改变了氮在草群各种群的分配比例；短花针茅贮氮比例增加，冷蒿的贮氮比例明显减少。

Under closing against grazing and rotational grazing conditions, the author studied the distributions and seasonal dynamis of nitrogen in aboveground part and underground part fresh grass, withered grass, Stipa breviflora, Artemisia frigida and other groups of Stipa breviflora desert steppe communities. The result showed that nitrogen reserve of the steppe community distributed mainly to underground part and grazing still increased proportion of nitrogen in underground part and changed proportion of nitrogen in various economic groups of Stipa breviflora desert steppe and made distribution proportion of nitrogen of Stipa breviflora increased. Nitrogen reserve in Artemisia frigida decreased obviously.