...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of oceanography >An Ecosystem Model Including Nitrogen Isotopes: Perspectives on a Study of the Marine Nitrogen Cycle
【24h】

An Ecosystem Model Including Nitrogen Isotopes: Perspectives on a Study of the Marine Nitrogen Cycle

机译：包括氮同位素的生态系统模型：海洋氮循环研究的观点

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We have developed an ecosystem model including two nitrogen isotopes (14N and 15N), and validated this model using an actual data set. A study of nitrogen isotopic ratios (δ15N) using a marine ecosystem model is thought to be most helpful in quantitatively understanding the marine nitrogen cycle. Moreover, the model study may indicate a new potential of δ15N as a tracer. This model has six compartments: phytoplankton, zooplankton, particulate organic nitrogen, dissolved organic nitrogen, nitrate and ammonium in a two-box model, and has biological processes with/without isotopic fractionation. We have applied this model to the Sea of Okhotsk and successfully reproduced the δ15N of nitrate measured in seawater and the seasonal variations in δ15N of sinking particles obtained from sediment trap experiments. Simulated δ15N of phytoplankton are determined by δ 15N of nitrate and ammonium, and the nitrogen f-ratio, defined as the ratio of nitrate assimilation by phytoplankton to total nitrogenous nutrient assimilation. Detailed considerations of biological processes in the spring and autumn blooms have demonstrated that there is a significant difference between simulated δ15N values of phytoplankton, which assimilates only nitrate, and only ammonium, respectively. We suggest that observations of δ 15N values of phytoplankton, nitrate and ammonium in the spring and autumn blooms may indicate the ratios of nutrient selectivity by phytoplankton. In winter, most of the simulated biogeochemical fluxes decrease rapidly, but nitrification flux decreases much more slowly than the other biogeochemical fluxes. Therefore, simulated δ15N values and concentrations of ammonium reflect almost only nitrification. We suggest that the nitrification rate can be parameterized with observations of δ15N of ammonium in winter and a sensitive study varying the parameter of nitrification rate.
机译：我们已经开发了包括两个氮同位素（14N和15N）的生态系统模型，并使用实际数据集验证了该模型。人们认为，使用海洋生态系统模型研究氮同位素比（δ15N）对定量了解海洋氮循环最有帮助。此外，模型研究可能表明δ15N作为示踪剂的新潜力。该模型有两个区室：浮游植物，浮游动物，有机微粒氮，溶解的有机氮，硝酸盐和铵盐处于两箱模型中，并具有带/不带同位素分馏的生物过程。我们已将此模型应用于鄂霍次克海，并成功地再现了从海水中测得的硝酸盐的δ15N和从沉积物捕集实验获得的下沉颗粒的δ15N的季节性变化。浮游植物的模拟δ15N由硝酸盐和铵的δ15N以及氮f比率确定，氮f比率定义为浮游植物对硝酸盐的吸收与总氮营养素吸收的比率。对春季和秋季盛开的生物过程的详细考虑表明，浮游植物的模拟δ15N值之间存在显着差异，浮游植物的δ15N值仅吸收硝酸盐，而仅吸收铵盐。我们认为，在春季和秋季开花时观察到的浮游植物，硝酸盐和铵的δ15N值可能表明了浮游植物对养分选择性的比率。在冬季，大多数模拟的生物地球化学通量迅速下降，但硝化通量的下降比其他生物地球化学通量下降得慢得多。因此，模拟的δ15N值和铵浓度几乎仅反映硝化作用。我们建议可以通过观察冬季的δ15N铵和敏感的研究来改变硝化速率的参数，从而对硝化速率进行参数化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号