【摘要】 南极海洋动物粪氨(NH3)的挥发与沉降过程是无冰区苔原生态系统氮素重要来源,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仍然很少有研究报道。本文通过室内模拟,研究了低温(4℃左右)与冻融条件下南极帝企鹅粪、阿德利企鹅粪和海豹粪土氨气产生与排放过程及其影响因素,结果表明:帝企鹅粪氨气排放通量最大,变化范围为0.765—17.4mg·kg-1·h-1,平均通量约为6.26mg·kg-1·h-1;阿德利企鹅粪氨气排放通量变化范围为0.652—3.707mg·kg-1·h-1,平均通量约为1.27mg·kg-1·h-1;而海豹粪土氨气排放通量很小,平均通量约0.141mg·kg-1·h-1。冻融过程对帝企鹅粪氨气排放通量影响很大,而对阿德利企鹅粪影响较小。另外,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。本文模拟的结果对于进一步研究南极生物圈氨的挥发过程及其对南极苔原生态系统氮循环的影响具有重要意义。更多还原

【Abstract】 The process of volatilization and deposition of ammonia is an important source of nitrogen in tundra ecosystems of ice-free zone. It also plays an important role in the maintenance of the stability of tundra ecosystem. However,very little work has been done to quantify NH3 flux from penguin guano and seal excreta. In this study,we simulated low temperature environment which kept penguin guano and seal excreta at about 4 ℃. Data from our experiments showed that Antarctic penguin guano showed high NH3 flux under low temperature. The NH3 fluxes of emperor penguin guano and Adélie penguin guano ranged from 0.765 to 17.4 mg·kg-1·h-1 (average flux of 6.26 mg·kg-1·h-1) and from 0.652 to 3.707 mg·kg-1·h-1 (average flux of 1.27 mg·kg-1·h-1),respectively. Ammonia flux from seal excreta was very small (average flux of 0.141 mg·kg-1·h-1). The process of freezing-thawing had an important impact on NH3 flux from emperor penguin guano and Adélie penguin guano. In addition,more NH3 was emitted from emperor penguin guano and Adélie penguin guano under the ventilated conditions than under the closed conditions,indicating that in Antarctic field high wind speed stimulates ammonia emissions from sea animal excreta. The results of this study are of great significance to further study the process of ammonia volatilization and nitrogen cycle of Antarctic tundra ecosystems.更多还原