• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>other >Tracing anthropogenic inputs in stream foods webs with stable carbon and nitrogen isotope systematics along an agricultural gradient
【2h】

Tracing anthropogenic inputs in stream foods webs with stable carbon and nitrogen isotope systematics along an agricultural gradient

机译：使用稳定的碳和氮同位素系统追踪农业梯度中人流食物网中的人为输入

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Stable carbon (13C) and nitrogen isotopes (15N) are useful tools in determining the presence of agricultural influences in freshwater ecosystems. Here we examined δ15N and δ13C signatures in nitrate, fish, and mussel tissues, from rivers in Southern Ontario, Canada, that vary in their catchment proportion of agriculture land use, nutrients and organic matter quality. We found comparatively 15N-enriched δ15N values in animal tissues and dissolved nitrates, relative to expected values characterized by natural sources. We also observed a strong, positive correlation between riparian agriculture percentages and δ15N values in animal tissues and nitrates, indicating a significant influence of agricultural land use and the probable dominance of organic fertilizer and manure inputs in particular. The use of a 15N-based equation for the estimation of fish trophic position confirmed dietary analyses is showing all fish species to be tertiary consumers, with a relatively consistent 15N-enrichment in animal tissues between trophic levels. This indicates that variability in 15N-trophic fractionation is minor, and that fish and mussel tissue δ15N values are largely representative of source nitrogen. However, the trophic fractionation value varied from accepted literature values, suggesting strong influences from either local environmental conditions or dietary variation. The δ13C datasets did not correlate with riparian agriculture, and animal δ13C signatures in their tissues are consistent with terrestrial C3 vegetation, suggesting the dominance of allochthonous DOC sources. We found that changes in water chemistry and dissolved organic matter quality brought about by agricultural inputs were clearly expressed in the δ15N signatures of animal tissues from all trophic levels. As such, this study confirmed the source of anthropogenic nitrogen in the studied watersheds, and demonstrated that this agriculturally-derived nitrogen could be traced with δ15N signatures through successive trophic levels in local aquatic food webs. The δ13C data was less diagnostic of local agriculture, due to the more complex interplay of carbon cycling and environmental conditions.
机译：稳定的碳（ 13 C）和氮同位素（ 15 N）是确定淡水生态系统中农业影响的有效工具。在这里，我们研究了加拿大安大略省南部河流中硝酸盐，鱼类和贻贝组织中的δ 15 N和δ 13 C信号，这些信号在农业集水区中的比例各不相同土地利用，养分和有机质。我们发现，动物组织和溶解的硝酸盐中相对富含 15 N的δ 15 N值，相对于自然来源的预期值。我们还观察到河岸农业百分比与动物组织和硝酸盐中的δ 15 N值之间存在强烈的正相关关系，这表明对农业土地利用有重要影响，尤其是有机肥料和肥料投入的主导地位。使用基于 15 N的方程式估算鱼的营养位置已证实饮食分析表明，所有鱼类都是第三级消费者，且具有相对一致的 15 N-营养层之间动物组织的富集。这表明 15 N营养级分的变化很小，鱼和贻贝组织的δ 15 N值在很大程度上代表了源氮。但是，营养分数值与公认的文献值有所不同，表明受当地环境条件或饮食变化的强烈影响。 δ 13 C数据集与河岸农业无关，其组织中的动物δ 13 C签名与陆地C3植被一致，表明异源DOC来源占主导地位。我们发现，在不同营养水平下，动物组织的δ 15 N信号清楚地表明了农业投入带来的水化学变化和溶解有机质的变化。因此，本研究证实了所研究流域的人为氮源，并证明了通过水生食物网中连续的营养水平可以用δ 15 N签名追踪这种农业来源的氮。 δ 13 C数据由于碳循环和环境条件之间更复杂的相互作用而对当地农业的诊断较少。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

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