松嫩平原盐碱草地主要植物群落土壤酶活性研究

Soil Enzyme Activities Under Plant Communities in Saline-sodic Grassland in Songnen Plain

采用现场采样及室内测试方法,研究了松嫩平原盐碱草地主要植物群落羊草(Leymus chinensis)、芦苇(Phragmites australis)、虎尾草(Chloris virgata)、碱茅(Puccinellia tenuiflora)、碱蓬(Suaeda glauca)以及盐碱荒地上土壤磷酸酶、脲酶和蔗糖酶的酶活性值以及垂直分布规律,并对3种酶活性与各理化因子之间进行了相关分析。结果表明:羊草群落的磷酸酶、脲酶、蔗糖酶活性值均为最高,芦苇、虎尾草群落土壤的酶活性值也较高,碱茅群落的土壤酶活性较低,而碱蓬群落土壤酶活性值最低,接近于盐碱荒地上土壤酶活性值。各植物群落的土壤酶活性垂直分布多表现为随着土壤深度的加深而呈现依次递减的规律,且表层(0～10 cm)土壤酶活性在所有根层总酶活性中所占的比例最大,占根层(0～40 cm)土壤酶活性的50%以上。土壤酶与土壤理化因子相关分析表明,土壤的土壤酶活性大多与EC、pH值显著负相关,对土壤酶活性影响较大;土壤酶活性与土壤养分正相关,脲酶与其相关性较大,蔗糖酶与养分的相关关系不是很明显。

Field sampling and lab testing method were used to study the alkaline phosphatase, urease, sucrase activities and the vertical distribution of these soil enzyme activities in Leymus chinensis, Phragmite communis, ChlorJs vJrgat, Puccinellia tenuiflor, Suaeda glauca plant communities and the saline-sodic wasteland mad to analyze the correlation of the three soil enzyme activities and the soil physical and chemical properties. The results showed that the alkaline phosphatase, urease and sucrase activities in the Leymus chinensis community were the highest, which were higher in the Phragmite communis and Chloris virgata communities, soil enzyme activities in the Suaeda glauca community were the lowest, which was close to these in the saline-sodic wasteland. The soil enzyme activities were decreased with the soil depth increased, soil enzyme activities in the surface layer was the largest in all root layers, which accounted for about 50% of the total soil enzyme in the root layers. Soil enzyme activities had negative correlation with electrical conductivity （EC） and pH value but had positive correlation with soil nutrients. The EC and pH values had great influences of the soil enzyme activities, the correlation of urease activity and soil nutrients were significant, but was not obvious between suerase activity and soil nutrients.