A stormflow/baseflow comparison of dissolved organic matter concentrations and bioavailability in an Appalachian stream
A stormflow/baseflow comparison of dissolved organic matter concentrations and bioavailability in an Appalachian stream
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DOI：
10.1023/a:1010643432253
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发表时间：
2001-01-01
期刊：
影响因子：
4
通讯作者：
McGlathery, KJ
中科院分区：
文献类型：
--
作者：
Buffam, I;Galloway, JN;McGlathery, KJ
在弗吉尼亚州谢南多厄国家公园（SNP）的一条阿巴拉契亚河流潘恩河（Paine Run）中，比较了暴雨流和基流时间之间溶解有机碳（DOC）和氮（DON）输送的模式。潘恩河是一条阿巴拉契亚河流，流经12.4 km（2）的森林集水区。潜在的流中的生态影响改变的浓度和/或化学组成的DOM在风暴期间也进行了检查，使用标准化的细菌生物测定。DOC和DON浓度在潘恩运行一贯低基流期间，并没有表现出季节性的模式。然而，在风暴期间，平均DOC和DON浓度大约增加了一倍，最大浓度发生在风暴过程线的上升段。DOM浓度对水流变化的快速响应表明，在风暴期间，DOM的近流或流内源。1997年潘恩径流中，暴雨径流（占全年径流量的4%和36%）对DOC、DON和NO3-通量的贡献均大于50%.在实验室细菌生物测定中，生长速率常数较高的潘恩运行雨水比基流水，但总DOM的生物可利用的部分是没有显着差异。总流DOC池的水柱细菌所占的比例估计从基流期间的0.03 +/-0.02%h（-1）增加到风暴期间的0.15 +/-0.04%h（-1）。这种吸收率将有一个最小的影响散装DOM浓度在潘恩运行，但风暴可能仍然有相当大的影响，细菌流社区动员他们进入水柱，并通过提供一个脉冲的DOM。
Patterns of dissolved organic carbon (DOC) and nitrogen (DON) delivery were compared between times of stormflow and baseflow in Paine Run, an Appalachian stream draining a 12.4 km(2) forested catchment in the Shenandoah National Park (SNP), Virginia. The potential in-stream ecological impact of altered concentrations and/or chemical composition of DOM during storms also was examined, using standardized bacterial bioassays. DOC and DON concentrations in Paine Run were consistently low during baseflow and did not show a seasonal pattern. During storms however, mean DOC and DON concentrations approximately doubled, with maximum concentrations occurring on the rising limb of storm hydrographs. The rapid response of DOM concentration to changes in flow suggests a near-stream or in-stream source of DOM during storms. Stormflow (4% of the time, 36% of the annual discharge) contributed > 50% of DOC, DON and NO3- flux in Paine Run during 1997. In laboratory bacterial bioassays, growth rate constants were higher on Paine Run stormflow water than on baseflow water, but the fraction of total DOM which was bioavailable was not significantly different. The fraction of the total stream DOC pool taken up by water column bacteria was estimated to increase from 0.03 +/- 0.02% h(-1) during baseflow, to 0.15 +/- 0.04% h(-1) during storms. This uptake rate would have a minimal effect on bulk DOM concentrations in Paine Run, but storms may still have considerable impact on the bacterial stream communities by mobilizing them into the water column and by supplying a pulse of DOM.