【作者】 张鑫；

【导师】 耿玉清； 徐明；

【作者基本信息】 北京林业大学 ， 土壤学， 2013， 硕士

【摘要】 土壤酶活性在湿地物质能量转换过程中起重要作用。为探究湖滨湿地酶活性动态变化规律及其影响因素,以鄱阳湖湖滨湿地滩地土壤和湖底沉积物为研究对象,基于目前国际土壤酶的研究方法,对土壤酶活性以及土壤性质和环境因子进行了研究。研究结果揭示了滩地土壤及沉积物酶活性在空间和时间变化中的差异,同时为湿地生态系统管理提供依据。主要研究结果如下：(1)湖滨滩地土壤纤维二糖酶、p-糖苷酶和酸性磷酸酶活性都在9月最高,而己丁质酶活性则在5月份达到最大值。采用干土基和有机碳基不同的表示方式表示的酶活性趋势基本相同。两种氧化还原酶对于有机碳含量变化的响应非常明显。酚氧化酶活性用干土基和有机碳基表示,分别在2月和5月达到最高。过氧化物酶活性在11月最高,但两种表示方法表现出不同的差异性。(2)湖底沉积物纤维二糖酶、β-糖苷酶、己丁质酶以及酸性磷酸酶活性变化趋势相似,在温度升高水位上升时活性较强,全年变化趋势呈现倒“V”形状。而酚氧化酶和过氧化物酶活性表现出明显的夏季低、冬季高的“V”字形趋势。(3)四种水解酶在不同淹水条件中的差异与酶种类和采样时产有关,5月、9月以及11月空间差异较明显,2月份没有显著差异。酚氧化酶和过氧化物酶活性空间差异显著,研究期间的酶活性在沉积物中都远高于滩地土壤。(4)湖滨湿地土壤酶活性受到水分温度影响显著,土壤水分含量与酶活性均显著相关。同时温度的升高促进了纤维二糖酶和酸性磷酸酶活性的增加,却抑制了过氧化物酶的活性。pH对酶活性的影响会在一定条件下抑制纤维二糖酶而促进酚氧化酶。有机碳与全氮会促进酶活性。沉积物中酶活性对于温度和碳氮变化会产生积极响应,纤维二糖酶、磷酸酶和过氧化物酶活性受温度影响显著,而其他三种酶活性则受碳氮含量影响更加明显。水温的升高会促进纤维二糖酶和磷酸酶活性,但同时会抑制过氧化物酶。pH对于纤维二糖酶和p-糖苷酶产生了显著的抑制效果。有机碳和全氮则会对β-糖苷酶、己丁质酶和酚氧化酶表现出明显的促进。综上所述,酶活性动态变化由多种因素引起,温度的升高促进了纤维二糖酶和酸性磷酸酶活性,同时可能会影响土壤水分含量从而抑制了过氧化物酶的活性。水温的升高会促进沉积物纤维二糖酶和磷酸酶活性但会抑制过氧化物酶。沉积物中有机碳和全氮会促进β-糖苷酶、己丁质酶和酚氧化酶活性更多还原

【Abstract】 Soil enzyme activities played an important role in the transformation of material and energy in the wetland. In order to explore the annual change of soil enzyme activity and it’s effected factors, soil enzyme activities were measured by using the international methods, meanwhile the relationships between soil enzyme activities and soil properties as well as environmental factors in beach soil and lake sediments in Poyang Lake. The results will reveal the differences of the enzyme activities in the spatial and temporal changes between beach soil and lake sediments, and also provide the basis for wetland ecosystem management. The main results are followed:(1) The activities of cellobiase and β-glucosidase in beach soil demonstrated the maximum in September, and the highest activities of chitinase appeared in May. No matter use the soil bases or the organic bases, the enzyme activity trend are same. It is very obvious that the two oxidoreductases response for the organic carbon content. Phenol oxidase activity reached the highest in February and May respectively by representing with the soil base and organic carbon base. The highest peroxidase activity was in November, but the enzyme activities represented by soil base and organic carbon base showed the different differences.(2) Cellobiose enzyme,(3-glucosidase, chitinase and acid phosphatase activities in lake sediment showed the same trend, the activities are high when the temperature increases and the water level rises, the annual trend inverted an "V" shape.(3) The differences among four hydrolase enzyme types in diffenent flooding conditions are related with sampling time, spatial differences are obvious in May,September and November, there was no difference in February. Spatial differences of Phenol oxidase and peroxidase activities are significant, the enzyme activities in the lake sediment of four months are much higher than in the beach soil. (4) The enzyme activities in beach soil are significantly affected by water temperature, the water content are significantly correlated with enzyme activities. The cellobiase and acid phosphatase activities increased were promoted by the elevated temperature, but inhibited the peroxidase activity. pH would promote the phenol oxidase activity and inhibit the cellobiase activity in certain condition. Organic carbon and the total nitrogen would promote the activities. The enzyme activities in lake sediment showed a positive response to temperature and carbon and nitrogen changes, the cellobiase, phosphatase and peroxidase activities were significantly affected by temperature, the other three enzyme activities were impacted by carbon and nitrogen content more significantly. Water temperature increasing can promote Cellobiase and phosphatase activities while inhibit peroxidase activity. pH were significantly inhibited the Cellobiase and β-glucosidase activities. Organic carbon and nitrogen showed significantly promoted to chitinase, β-glucosidase and phenol oxidase activities.In conclusion, enzyme activity dynamics caused by many factors, temperature promotes Cellobiase and acid phosphatase activity, and may affect the soil moisture content thus inhibiting the activity of peroxidase.Water temperature will promote Cellobiase and phosphatase activities but will inhibit peroxidase activities in sediment. Organic carbon and nitrogen will promote the activities of β-glucosidase, chitinase and phenol oxidase in sediment.更多还原