莫莫格湿地土壤酶活性特征及其与土壤铁的相关分析

Characteristics of several soil enzyme activities and the correlations with soil iron in Momoge wetland

以莫莫格湿地芦苇沼泽(LW)、芦苇-羊草沼泽化草甸(L-Y)和羊草草甸(YC)3种类型湿地土壤为对象,研究了土壤的酶活性特征并对土壤酶与土壤铁进行了相关分析.结果表明:湿地土壤酶活性的垂直变化基本表现为从表层向深层递减的规律,其中Fe2O3还原酶活性和蔗糖酶活性在土壤表层最强.3种类型区土壤Fe2O3还原酶和磷酸酶均表现为LW>YC>L-Y.土壤酶之间还存在着一定的相关性,Fe2O3还原酶与酸性磷酸酶、过氧化氢酶与中性磷酸酶、蔗糖酶与中性磷酸酶均呈显著相关,蔗糖酶与酸性磷酸酶极显著相关,3种磷酸酶之间也存在极显著的相关关系.从土壤酶与土壤铁的相关分析结果看,湿地土壤Fe2O3还原酶与土壤络合铁、无定形铁和全铁均存在极显著或显著的相关性,土壤游离铁、无定形铁分别与蔗糖酶和中性磷酸酶显著相关.不同土壤环境中土壤铁与各种酶活性之间的相关性有明显差异.LW湿地土壤蔗糖酶与游离铁、无定形铁和全铁均呈极显著或显著正相关;L-Y湿地土壤铁与Fe2O3还原酶、磷酸酶、蔗糖酶之间均有显著的负相关性;YC中无定形铁与Fe2O3还原酶呈显著正相关性,其他土壤铁与酶活性相关均不明显.

The typical soil enzyme activities and the iron oxide concentrations in the Momoge wetland soils of three community types, Phragrnites australis marsh （LW）, P. australis - Leymus chinensis marshy meadow fLY） and L. chinensis meadow （YC）, were tested and their correlations were analyed. The results showed that the soil enzyme activities decreased from the upper soil layers to the lower ones,with the highest activities of Fe2O3 reductase and invertase presenting in the surface layers. Among three wetland soil types, the enzyme activities of Fe2O3 reduetase and phosphatase are expressed as LW〉YC〉LY. Significant correlations were observed between Fe2O3 reductase and acid phosphatase, catalase and neutral phosphatase, as well as invertase and neutral phosphatase. Extremely significant correlations were observed between invertase and acid phosphatase, as well as the three kinds of phosphatase. There were significant or extremely significant correlations between Fe2O3 reductase and soil chelated iron oxides, Fe2O3 reduetase and amorphous iron oxides, Fe2O3 reductase and total iron concentration, invertase and free iron oxides, invertase and amorphous iron oxides,neutral phosphatase and free iron oxides, as well as neutral phosphatase and amorphous iron oxides. These correlations differed obviously from different soil types. In LW wetland soil, the positive correlations between invertase and free iron oxides, amorphous iron oxides and total iron concentrations were all significant or extremely significant. In LY wetland soil,there were significant negative correlations between total iron concentration and Fe2 O3 reductase, total iron concentration and phosphatase,and total iron concentration and invertase. In YC wetland soil,only Fe2 O3 reductase was significantly positively correlated with amorphous iron oxides, while the correlations between other soil enzyme activities and soil iron correlation were all insignificant.