【作者】 孙建军；

【导师】 朱仁斌；

【作者基本信息】 中国科学技术大学 ， 环境科学， 2010， 硕士

【摘要】 南极海洋动物粪NH3和基质结合态磷化氢（MBP）是无冰区苔原生态系统氮磷元素重要来源,对维持苔原生态系统的稳定起着重要作用;但目前对于南极典型海洋动物粪氨的挥发过程和MBP的研究仍很少有研究报道。本文采集了东南极4个企鹅聚集地企鹅粪（粪土）和1个西南极的海豹聚集地海豹粪,在室内模拟测定了这些样品的潜在的氨气排放通量,以及冻融循环与各种环境因子对氨气排放的影响。采集了东南极5个企鹅聚集地企鹅粪（土）,1个湖泊沉积物以及北极黄河站附近的1个海鸟粪,1个湖泊沉积物,测量了MBP含量随深度增加的变化及其环境影响因子。NH3研究结果表明:在冻融循环过程中,冻结期间各样品的氨气排放量很小,而在融化过程中氨气的排放通量急剧增加,帝企鹅粪、阿德利企鹅粪和企鹅粪土分别达到最大值,分别为17.4 mgNH3 kg^-1 h^-1,3.707 mg.kg^-1.h^-1和12.29 mgNH3 kg^-1 h^-1,表明冻融过程是影响南极典型海洋动物粪氨气排放强度的夏季变化的主要因素。在融化过程中,帝企鹅粪、阿德利企鹅粪和海豹粪的平均排放通量分别为7.66±4.33 mgNH3 kg^-1 h^-1,1.31±0.64 mgNH3 kg^-1 h^-1和0.33±0.39 mgNH3 kg^-1 h^-1,明显高于企鹅粪土的排放量。企鹅粪（土）NH3-N的损失率（NH3-N/TN）存在较大的变化范围（达0.1-82.4‰）。另外,模拟结果也表明:温度,TN,TC和pH这些环境因素都对氨气排放也有重要影响。首次获得了南极海洋动物粪土氨气排放通量与温度、pH、TN和TC之间的定量关系,氨气排放通量与温度和pH呈指数变化,而与TN、TC呈明显直线相关。粪（土）干湿之间变化和通气条件的变化也是影响氨气排放的重要因素。帝企鹅粪和阿德利企鹅粪氨气排放量在通气条件下明显大于封闭条件,表明南极野外大风条件下可能加速海洋动物粪氨的挥发过程。本文研究结果表明南极海洋动物聚集地是巨大的,潜在的氨气排放源。南极夏季频繁的温度变化导致大量的动物粪沉积承受频繁的冻融过程,冻融过程会极大的增加氨气挥发量,这个过程产生的排放量占很大部分的每年排放量。MBP研究结果表明:各粪土及沉积物不同剖面MBP随深度的增加显示了不同的变化特征,高浓度MBP存在于沉积物还原性强的底层或次表层,湖泊沉积物MBP平均含量显然大于其他粪和粪土的MBP含量。比表面积较大的粘土更有利于MBP的赋存;含水量大的湖泊沉积物MBP含量相对较高;较高含量的有机C和碱性磷酸酶活性有利于MBP生成;pH接近中性的土壤和沉积物有利于MBP的保存。没有发现MBP含量与无机磷、有机磷和可溶性总磷浓度存在明显的相关性,MBP也受到各种金属盐类的影响,暗示着沉积物中MBP控制因素的复杂性。本文模拟的结果对于进一步研究南北极生物圈氨的挥发过程和MBP及其对极区苔原生态系统氮磷地球化学循环的影响具有重要意义。更多还原

【Abstract】 Ammonia (NH3) volatilization and matrix-bound phosphine (MBP) from sea animal colonies provide an important nitrogen and phosphorus source for terrestrial ecosystems in the Antarctica. However, very little attention has been paid to quantify NH3 emissions and MBP from sea animal colonies and lake sediments. In NH3 study, penguin guano (ornithogenic materials) from four penguin colonies and the soils from one seal colony were collected in coastal Antarctica. In MBP study, penguin guano (ornithogenic materials) and one lake sediment were collected in coastal Antarctica; sea animal guano and one lake sediment were collected near the Yellow River Station in Arctica. Laboratory experiments of NH3 emission were conducted to investigate potential NH3 emissions from these samples and effects of freezing-thawing cycles (FTCs) and environmental factors on NH3 fluxes. The fluxes were extremely low (close to zero) from the frozen samples. Significantly enhanced NH3 emissions were observed following the thawing with the maximum flux of 17.4 mg NH3 kg-1 h-1 for emperor penguin guanos, 3.707 mg kg-1 h-1 for Adélie penguin guanos and 12.29 mg NH3 kg-1 h-1 for ornithogenic materials. The mean fluxes were 7.66±4.33 mg NH3 kg-1 h-1 from emperor penguin guano, 1.31±0.64 mgNH3 kg-1 h-1 from Adélie penguin guano and 0.33±0.39 mgNH3 kg-1 h-1 from seal colony soils during the thawing. NH3 emissions from penguin guano were higher than those from ornithogenic materials during FTCs. The specific NH3-N production rates (NH3-N/TN) from penguin guano and ornithogenic materials are considerably large with the range of 0.1-82.4‰. The temperature, total nitrogen concentration, total carbon concentration and pH were significant predictor variables for NH3 fluxes from penguin guano and ornithogenic materials. The NH3 fluxes exponentially increased with enhanced temperature and pH, and they showed a significant linear correlation with TN and TC concentration. The drying-wetting conversion and the ventilated conditions also had an important effect on NH3 emissions, indicating that in Antarctic field high wind speed stimulates ammonia emissions from sea animal excreta. This study showed that penguin guano and ornithogenic materials are significant NH3 emission sources. In coastal Antarctica, the freezing-thawing frequency for sea animal excreta and ornithogenic materials is considerably high throughout the summer, and FTC-induced NH3 emissions might account for a large proportion of annual flux from sea animal colonies. Stuyies of MBP were conducted to measure the variations of MBP concentration with depths. High concentrations of MBP present in the bottom or sub-surface sediments which have the strong reducing property. The mean concentrations of MBP in lake sediments were higher than those in sea animal guanos and ornithogenic materials. Clay sediments are favorable for MBP accumulation due to large surface area and adsorption pots, and larger water content, and neutral condition is also favor to the exsistence of MBP. TOC and alkaline phosphatase activity not only proved their effect on MBP in the sediments, but also showed that biological activity may control MBP production. There was no obvious correlation between MBP and soluble phosphorus, organic phosphorus and inorganic phosphorus. Metal salts had no significant effect on the concentrations of MBP. Those imply that MBP production and elimination are complicated, and more studies should be done. The results of this study are of great significance to further study the process of ammonia volatilization and MBP production, as well nitrogen and phosphorus biogeochemical cycle of Antarctic tundra ecosystems.更多还原