长白山区金川泥炭沼泽土壤酶活性特征

Characteristics of Soil Enzyme Activity of Peat Bog in Jinchuan,Changbai Mountain

土壤酶是泥炭地生态系统碳循环过程的重要参与者,影响着泥炭沼泽土壤有机碳库的变化及其在全球碳循环中的作用。以长白山区金川泥炭沼泽为研究对象,于2017年8月17日,分别采集臌囊薹草（Carex schmidtii）草丘、丘间和油桦（Betula fruticosa）群落下0～50 cm深度土壤,测定其3种水解酶（β-1,4-葡萄糖苷酶、β-1,4-N-乙酰葡糖胺糖苷酶、酸性磷酸酶）和1种氧化酶（过氧化物酶）的活性,并分析其影响因素。研究结果表明,在0～10cm深度,油桦群落下土壤中β-1,4-葡萄糖苷酶活性平均值为（2 116.78±65.41） nmol/（g·h）,显著高于臌囊薹草草丘和丘间土壤（n=3,p〈0.05）;土壤酸性磷酸酶和过氧化物酶活性平均值分别为（4 786.57±738.84） nmol/（g·h）和（8.98±0.377） nmol/（g·h）,显著高于臌囊薹草丘间土壤（n=3,p〈0.05）,与草丘土壤无显著差异（n=3,p〉0.05）;油桦群落下的土壤中β-1,4-N-乙酰葡糖胺糖苷酶活性平均值为（615.67±43.49） nmol/（g·h）,显著低于臌囊薹草草丘土壤（n=3,p〈0.05）。在臌囊薹草草丘土壤中,β-1,4-葡萄糖苷酶、β-1,4-N-乙酰葡糖胺糖苷酶、酸性磷酸酶和过氧化物酶活性都显著高于丘间土壤（n=3,p〈0.05）。在0～50 cm深度土壤中,随着土壤深度的增加,土壤β-1,4-葡萄糖苷酶、β-1,4-N-乙酰葡糖胺糖苷酶活性在臌囊薹草草丘和丘间呈单峰型变化,而在油桦群落下的土壤中基本保持不变。土壤酸性磷酸酶活性在臌囊薹草草丘和丘间10～20 cm深度土壤中达到最大,而在油桦群落下的0～10 cm深度土壤中最大。在臌囊薹草群落草丘和油桦群落下的土壤中,随着土壤深度的增加,土壤过氧化物酶活性波动变化,而在臌囊薹草丘间土壤中,过氧化物酶活性逐渐增大。土壤含水量和全氮含量是影响泥炭沼泽土壤酶活性空间异质性的主要因子。

Soil enzyme is an important participants of the carbon cycling in peatland, which influencing the soil organic carbon pool in peatland. The samples were collected from the 0-50 cm depth＇s soils of the Carex schmidtii hummock and gap and under Betula fruticosa community in Jinchuan peat bog of Changbai Mountain, Northeast of China on August 17, 2017. The activities of three hydrolyzing enzymes（β-1,4-glucosidase, β-1,4-N-acetylglucosaminidase and acid phosphatase） and one oxidase（peroxidase） were determined, and the influencing factors were analysed. At the depth of 0-10 cm, β-1,4-glucosidase activity was（2 116.78±65.41） nmol/（g· h） in the soil with Betula fruticosa community and significantly higher than that of Carex schmidtii hummock and gap（n=3, p〈0.05）. Soil acid phosphatase and peroxidase activities were（4 786.57±738.84） nmol/（g· h） and（8.98±0.377） nmol/（g· h） in the soil with Betula fruticosa community, and significantly higher than those of Carex schmidtii gap（n=3, p〈0.05）, but there was no significant difference with the Carex schmidtii hummock. The soil β-1,4-N-acetylglucosaminidase activity was（2 116.78 ± 65.41）nmol/（g · h） in Betula fruticosa community and significantly lower than that of the hummock of the Carex schmidtii（n=3, p〈0.05）. In the Carex schmidtii hummock, the soil β-1,4-glucosidase, β-1,4-Nacetylglucosaminidase, acid phosphatase and peroxidase activities were significantly higher than those in the gap（n=3, p〈0.05）. At the depth of 0-50 cm, soil β-1,4-glucosidase and β-1,4-N-acetylglucosaminidase activities showed single peak variations with the depth increasing in Carex schmidtii hummock and gap, but no differences among different depths in the soil with Betula fruticosa community. Soil acid phosphatase activity was highest at 10-20 cm depth in Carex schmidtii hummock and gap, but highest at 0-10 cm depth in the soil with Betula fruticosa community. Soil peroxidase activity fluctuated with the increase of the depth in the soil with Betula fruticosa community and the Carex schmidtii hummock, while increased gradually in the Carex schmidtii gap. Soil water content and total nitrogen contents were the main environmental factors affecting the spatial heterogeneity of soil enzyme activities in peat mire.