不同草原植被碱化草甸土的酶活性

在羊草草原不同植物群落土壤中，脲酶、磷酸酶和纤维素酶活性的变化是羊草群 落＞拂子茅群落＞碱茅群落＞虎尾草群落＞碱蓬群落＞光碱斑．脱氢酶是拂子茅群落＞ 羊草群落＞虎尾草群落＞碱茅群落＞碱蓬群落＞光碱斑．脲酶、磷酸酶和纤维素酶的时间 变化曲线呈抛物线型，最大值均出现在８月，最小值出现在６月或１０月．脱氢酶变化的最 大值出现在６月，然后逐渐减弱，１０月出现最低值．关联分析表明各土壤因子对脲酶作用 大小的关联序为全 Ｎ＞有机质＞土壤容重＞全 Ｐ＞ ＰＨ ；磷酸酶为全 Ｐ＞有机质＞ ｐＨ＞全 Ｎ＞土壤容重；脱氢酶为全Ｎ＞有机质＞全Ｐ＞土壤容重＞ｐＨ；纤维素酶为全Ｎ＞有机质 ＞全 Ｐ＞ｐＨ＞土壤容重．脲酶、磷酸酶和纤维素酶活性与微生物生物量关系随着微生物生 物量的增加酶活性逐渐增强．脱氢酶与微生物生物量的关系不明显．

Enzymic activity of alkaline meadow soil with different grassland vegetations

In soils with different grassland plant communities. the activities of urease, phaphatase and celluase were in the order of A. chinense community > Calamaguostis elegies community > Puccinellia tenuiflora community> C. virgata community> Suaeda glauca community> alkaline spot; and dehydrogenase activity was in the order of C. epigeios community > A.chi nense community> C' virgata community> P' tenuiflora community> S' glauca community >alkaline spot. The temporal dynamics of urease, phaphatase and Celluase activities was parabolas in shape, the maximum in August and the minimum in June or October. The dehydrogenase activity reached the highest value in June, and the lowest value in October. Interrelated analysis showed that soil factors affecting urease activity were total N>Organic matter > soil unit weight > total P > pH; for phaphatase. were total P >organic matter > pH> total N > soil unit weight; for dehydrogenase were total N >organic matter> total p>soil unit weight > pH; and for celluase, were total N > organic matter > total P > pH > soil unit weight. The enzymic activities were gradually strengthened with increasing biomass, but the correlation between dehydrogenase activity and microorganism biomass was not obvious.