Millennial-aged organic carbon subsidies to a modern river food web
Millennial-aged organic carbon subsidies to a modern river food web
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DOI：
10.1890/09-0330.1
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发表时间：
2010-08-01
期刊：
影响因子：
4.8
通讯作者：
Raymond, Peter
中科院分区：
文献类型：
--
作者：
Caraco, Nina;Bauer, James E.;Raymond, Peter
最近的研究表明，高度老化的物质是大多数河流输送的有机物的主要成分。然而，很少有研究使用天然的C-14来追踪这种陈年物质进入现代河流食物网的可能性。在这里，我们使用自然丰度C-14、C-13和氢(H-2)来追踪古老的和当代的有机物对一大条温带河流(美国纽约哈德逊河)中重要的消费者群体--甲壳类浮游动物的贡献。与河流或其分水岭的现代初级生产量(C-14=-60ppm至+50ppm)相比，浮游动物的C-14被高度消耗(平均Delta C-14=-240ppm)。为了解释观测到的碳-14消耗，浮游动物必须得到高度老化的颗粒有机碳的补贴。IsoSource模型表明，如果老年有机质源是在3400年前生产的，老年膳食补贴的范围类似于57%，如果所使用的有机碳的年龄为>；=50000年，包括数百万年的化石材料，则类似于21%。对河流浮游动物的这种老化碳补贴的规模表明，在某些情况下，现代河流食物网可能会被缓冲，不受当今初级生产力设置的限制。
Recent studies indicate that highly aged material is a major component of organic matter transported by most rivers. However, few studies have used natural C-14 to trace the potential entry of this aged material into modern river food webs. Here we use natural abundance C-14, C-13, and deuterium (H-2) to trace the contribution of aged and contemporary organic matter to an important group of consumers, crustacean zooplankton, in a large temperate river (the Hudson River, New York, USA). Zooplankton were highly C-14 depleted (mean Delta C-14 = -240 parts per thousand) compared to modern primary production in the river or its watershed (Delta C-14 = -60 parts per thousand to +50 parts per thousand). In order to account for the observed C-14 depletion, zooplankton must be subsidized by highly aged particulate organic carbon. IsoSource modeling suggests that the range of the aged dietary subsidy is between similar to 57%, if the aged organic matter source was produced 3400 years ago, and similar to 21%, if the organic carbon used is >= 50 000 years in age, including fossil material that is millions of years in age. The magnitude of this aged carbon subsidy to river zooplankton suggests that modern river food webs may in some cases be buffered from the limitations set by present-day primary production.