The impact of precipitation intensity and vegetation in the catchment area on autochthonous and allochthonous carbon transfer in stream biofilm food webs

流域降水强度和植被对河流生物膜食物网中本地和异地碳转移的影响

• 批准号: 233302479
• 负责人: Dr. Anne-Gret Seifert
• 金额: --
• 依托单位: ArbeitsgruppeTierökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/233302479?language=en
• 关键词: impact; precipitation; intensity; vegetation; catchment

In rivers and streams, biofilms are major sites of carbon cycling. They retain large amounts of dissolved organic carbon (DOC) and consequently are most important for the development of aquatic organisms on higher trophic levels. Besides autochthonous primary production, which supports heterotrophic production in biofilms, large amounts of organic carbon (OC) are derived from the surrounding catchment areas. More precipitation and more frequent and severe floods due to climate change will increase the transport of material into streams. Moreover, catchment characteristics including vegetation affect the transport and nature of DOC into aquatic ecosystems. Thus, carbon dynamics depend on how a stream is embedded within and interacts with its surrounding terrestrial environment. Despite its importance for carbon cycling it is not understood to which extent autochthonous or allochthonous carbon is used in biofilms and how increased addition of allochthonous carbon determines the relative use of both carbon sources. The combined application of 13C and 14C analysis on differently labeled DOC sources intend to answer to which extent DOC from different sources is used by bacteria in biofilms and finally transported to higher trophic levels. The use of 13C and 14C signals on carbon compounds and biomarkers is an excellent method to determine carbon sources for microorganisms and the transport of labeled material within the food web.

在河流和溪流中，生物膜是碳循环的主要场所。它们保留了大量的溶解有机碳（DOC），因此对较高营养水平的水生生物的发展至关重要。除了支持生物膜中异养生产的本地初级生产外，大量的有机碳（OC）来自周围的集水区。由于气候变化，降水量增加，洪水更加频繁和严重，将增加物质流入河流的数量。此外，集水区的特征，包括植被影响DOC的传输和性质的水生生态系统。因此，碳动力学取决于河流如何嵌入其周围的陆地环境并与之相互作用。尽管它对碳循环的重要性，但还不了解在生物膜中使用的原生碳或外来碳的程度以及外来碳的增加如何决定两种碳源的相对使用。13 C和14 C分析的不同标记的DOC源的组合应用，旨在回答在何种程度上从不同来源的DOC被生物膜中的细菌使用，并最终运输到更高的营养级。碳化合物和生物标志物上的13C和14C信号的使用是确定微生物碳源和食物网内标记材料运输的极好方法。