首页> 外文期刊>Ecological research >Use of carbon-13 and carbon-14 natural abundances for stream food web studies
【24h】

Use of carbon-13 and carbon-14 natural abundances for stream food web studies

机译:碳13和碳14天然丰度在流食网研究中的用途

获取原文
获取原文并翻译 | 示例
       

摘要

We review the use of stable carbon isotope ratios δ~(13)C) and radiocarbon natural abundances (Δ~(14)C) for stream food web studies. The δ~(13)C value of primary producers (e.g., periphytic algae, hereafter periphyton) in streams is controlled by isotopic frac-tionation during photosynthesis and variable δ~(13)C of dissolved CO_2. When periphyton δ~(13)C differs from that of terrestrial primary producers, the relative contribution of autochthony and allochthony to stream food webs can be calculated. Moreover, the variation in periphyton δ~(13)C can reveal how much stream consumers rely on local resources because each stream habitat (e.g., riffle vs. pool, open vs. shaded) usually has a distinctive δ~(13)C. However, periphyton δ~(13)C often overlaps with that of terrestrial organic matter. On the other hand, periphyton Δ~(14)C is less variable than δ~(13)C among habitats, and reflects the Δ~(14)C of dissolved CO_2, which could be a mixture of "aged" (Δ~(14)C < 0 ‰) and "modern" (Δ~(14)C > 0 ‰) carbon. This is because the Δ~(14)C is corrected by its δ~(13)C value for the isotopic fractionation during photosynthesis. Recent studies and our data indicate that many stream food webs are supported by "aged" carbon derived from the watershed via autochthonous production. The combined use of δ~(13)C and Δ~(14)C allows robust estimation of the carbon transfer pathway in a stream food web at multiple spatial scales ranging from the stream habitat level (e.g., riffle and pool) to watershed level (autochthony and allochthony). Furthermore, the Δ~(14)C of stream food webs will expand our understanding about the time frame of carbon cycles in the watersheds.
机译:我们回顾了稳定碳同位素比δ〜(13)C和放射性碳自然丰度(Δ〜(14)C)在流食网研究中的应用。流中主要生产者(例如,附生藻类,以下称附生植物)的δ〜(13)C值受光合作用过程中的同位素碎裂和溶解的CO_2的δ〜(13)C值控制。当周围植物的δ〜(13)C与陆地初级生产者的不同时,可以计算出自养和异养对流食网的相对贡献。此外,浮游植物δ〜(13)C的变化可以揭示多少溪流消费者依赖当地资源,因为每个溪流的生境(例如浅滩与水池,开阔与阴暗)通常具有独特的δ〜(13)C。然而,植物浮游生物δ〜(13)C经常与陆地有机质重叠。另一方面,生境中浮游植物的Δ〜(14)C的变化小于δ〜(13)C,并反映了溶解的CO_2的Δ〜(14)C,这可能是“衰老”(Δ〜 (14)C <0‰)和“现代”(Δ〜(14)C> 0‰)碳。这是因为在光合作用过程中,通过同位素分馏的δ〜(13)C值对Δ〜(14)C进行了校正。最近的研究和我们的数据表明,许多流食网都由通过流域生产自流域获得的“老化”碳来支撑。结合使用δ〜(13)C和Δ〜(14)C,可以在从河流生境水平(例如浅滩和水池)到集水区水平的多个空间尺度上,可靠地估算河流食物网中的碳转移途径(土生土长和异源土)。此外,流食网的Δ〜(14)C将扩展我们对流域碳循环时间框架的理解。

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