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摘要
The present paper reports on the year-long study of atmospheric precipitation (rain and snow) composition, including nitrogen, phosphorus and mineral matter as conductivity, in ice-free area of western coast of Admiralty Bay (King George Island). The effects of the local Adelie penguin colony on nitrogen and phosphorus concentrations in atmospheric precipitation, as well as the role of wind on nitrogen and phosphorus enrichment of ice-free areas uncovered by a progressing deglaciation of the Ecology Glacier (ASPA 128) were examined. The effect of marine influence on the mineral matter level (as conductivity) in atmospheric precipitation was examined too. The determination of conductivity, nitrogen and phosphorus were assayed according to standard methods. Conductivity, nitrogen and phosphorus concentrations in atmospheric precipitation differed depending on sampling sites location, precipitation type (rain or snow), season (summer or winter), and also distance from a penguin rookery. The mean conductivity of rain and snow amounted to 189 mu S cm(-1) and was higher in rain (up to 290 mu S cm(-1)) than in snow samples (87 mu S cm(-1)). Mean total nitrogen and total phosphorus concentrations in precipitation amounted to 0.208 mg N dm(-3) and 0.028 mg P dm(-3), respectively. A higher conductivity was recorded in the precipitation transported by NNW winds (200 mu S cm(-1)), and lower in the precipitation transported by SSE winds (80 mu S cm(-1)). The seasonal variability of conductivity was characterized by a higher values during summer (320 mu S cm(-1)) and lower - during winter (90 mu S cm(-1)). The most nutrientrich samples were those collected in the centre of the penguin rookery, average values of TN and TP concentrations were 0.450 mg N dm(-3) and 0.090 mg P dm(-3), respectively. At the other sites concentrations of TN and TP were lower. Seasonal variabilty of nitrogen and phosphorus concentrations were usually characterized by minimal concentrations during winter and maximal - during spring or summer. The concentrations of nitrogen and phosphorus were characterized by a statistically significant negative relation along the distance from the penguin rookery and along the altitude of sampling sites. The influence of the penguin rookery on the higher concentrations of biogenic compounds caused the high concentrations of ammonium nitrogen (averaging about 0.250 mg N dm(-3)) during summer at all sampling sites, even at those, located farthest away (about 2200 m) from the penguin colony. The annual nitrogen and phosphorus loads deposited by atmospheric precipitation onto the ice-free area were estimated at about 0.752 kg N ha(-1) and 0.061 kg P ha(-1), respectively.
- 出版日期2007
