高寒牧区醉马草草丛肥岛效应的研究

Studies on Effect of Fertile Island of Achnatherum inebrians Tussock in Alpine Pastoral

对高寒牧区醉马草(Achnatherum inebrians)草丛肥岛效应进行了研究。结果表明:(1)醉马草草丛中心土壤养分明显高于空地。(2)醉马草草丛对土壤养分富集作用从土壤表层向深层递减,从中心向边缘递减。(3)从草丛中心到距草丛100cm土壤养分含量变化规律为:有机质在0～20cm土层先减小后不变,在20～30cm土层持续不变;全氮和速效钾先减小后不变;全磷和速效氮在0～10cm土层先减小后增加,在10～30cm土层先减小后不变;全钾无明显规律;pH在0～20cm土层先升高后不变,在20～30cm土层先降低、再不变、后升高;速效磷在0～20cm土层先减小后增加,在20～30cm土层先减小后不变。整体而言,醉马草草丛全氮和速效钾、全磷和速效氮变化规律一致,其他养分变化规律各异。

The effect of fertile island of Achnatherums inebrians tussock was studied in alpine pastoral areas. The results showed that： （1） the soil nutrient in the centre of Achnatherums inebrians tussock was more than that in the tussock gap. （2） nutrient enrichment in fertile island of Achnatherums inebrians tussock descended from the soil surface to the deep, from the center to the edge. （3） From the grass center to 100cm away, soil nutrient content changed as follows： organic matter content in 0-20cm soil layer first decreased and then remain unchanged, that in 20-30cm soil layer unchanged; total nitrogen and available K content first decreased and then unchanged; total phosphorus and available N in 0-10cm soil layer first decreased and then increased,that in 10-30cm soil layer first decreased and then remain unchanged; there was no significant difference in total potassium content; pH in 0-20cm layer first increased and then un- changed, that in 20-30cm soil layer, first lower, and then the same, and finally increased; available phosphorus in 0-20cm soil first decreased and then increased, that in 20-30cm soil first decreased and then remained unchanged; Generally, the variation of total nitrogen and available K was the same,variation of total phosphorus and available N was the same, the variation pattern of other soil nutrients in Achnatherums inebrians tussock was different in terms of different nutrients or properties.