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为了探讨与高寒区沼泽化草甸及由其退化的草甸、沙地土壤中的有机碳、氮和磷转化相关的酶活性的变化机制,在青海湖流域小泊湖区的沼泽化草甸、草甸和沙地中,分别采集0~10 cm、10~20 cm和20~30 cm深度的土壤样品,比较不同采样地土壤的理化性质、7种水解酶和酚氧化酶活性的差异,并分析土壤理化性质对酶活性的影响。研究结果显示,与沼泽化草甸相比,草甸土壤β-葡萄糖苷酶、纤维二糖酶、几丁质酶、亮氨酸氨基肽酶和甘氨酸氨基肽酶的酶活性分别下降了44.6%、47.1%、35.7%、66.9%和82.5%;相应的沙地土壤酶活性则分别下降了91.3%、79.4%、76.2%、79.1%和94.7%;草甸土壤酚氧化酶活性很高;各采样地土壤β-葡萄糖苷酶、纤维二糖酶、几丁质酶活性与水溶性有机碳、氮含量显著相关,土壤含水量和水溶性有机碳、氮含量能够解释不同采样地土壤肽酶活性的差异,硝态氮和有效磷含量能够解释不同采样地土壤磷酸酶活性的差异;土壤含水量、p H和水溶性有机碳对酚氧化酶活性影响显著。与沼泽化草甸土壤相比,草甸和沙地土壤中与碳、氮转化相关的水解酶的活性明显降低。
In order to explore the mechanism of the changes of enzyme activities related to organic carbon, nitrogen and phosphorus transformation in the marsh meadow and its degraded meadow in the alpine region, the swampy meadow and grass in the Xiaobohu Lake in the Qinghai Lake Basin The soil samples of 0 ~ 10 cm, 10 ~ 20 cm and 20 ~ 30 cm depths were collected from meadow, meadow and sandland respectively. The physical and chemical properties, the differences of seven soil hydrolase and phenoloxidase activities in different sampling sites were compared. Physicochemical properties of the enzyme activity. The results showed that the activities of β-glucosidase, cellobiase, chitinase, leucine aminopeptidase and glycine aminopeptidase in meadow soil decreased by 44.6% , 47.1%, 35.7%, 66.9% and 82.5% respectively. The soil enzyme activity in the corresponding sandy land decreased by 91.3%, 79.4%, 76.2%, 79.1% and 94.7%, respectively. The activity of phenoloxidase in meadow soil was high. Soil β-glucosidase, cellobiase and chitinase activities were significantly correlated with water-soluble organic carbon and nitrogen in the sampling sites. Soil moisture content and water-soluble organic carbon and nitrogen contents could explain the soil peptidase activities in different sampling sites The difference of soil phosphatase activity in different sampling sites could be explained by the difference of nitrate nitrogen and available phosphorus. Soil moisture, p H and water-soluble organic carbon had significant effects on the activity of phenoloxidase. Compared with the swamp meadow soil, the activities of hydrolases associated with carbon and nitrogen transformation in meadow and sand soils were significantly reduced.