Food web analysis of southern California coastal wetlands using multiple stable isotopes
Food web analysis of southern California coastal wetlands using multiple stable isotopes
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DOI：
10.1007/s004420050159
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发表时间：
1997-04
期刊：
影响因子：
2.7
通讯作者：
T. Kwak;J. Zedler
中科院分区：
文献类型：
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作者：
T. Kwak;J. Zedler
使用碳、氮和硫稳定同位素来表征蒂华纳河口和圣迭吉托泻湖的食物网（即碳源和消费者的营养状况）。生产者群体的区分最明显的是碳，其次是硫，最不明显的是氮同位素测量。消费者 15N 同位素富集表明蒂华纳河口食物网有四个营养级，圣迭吉托泻湖有三个营养级。湿地之间鱼类的多种同位素比分布的显着差异表明圣迭吉托泻湖的食物网不如蒂华纳河口的食物网复杂。来源和消费者之间的关联表明，来自潮间带大型藻类、沼泽微藻和大米草的投入物提供了支持无脊椎动物、鱼类和轻足楝树（Rallus longirostris levipes）的有机物质。这三个生产者占据潮汐通道、低盐沼和中盐沼栖息地。唯一依赖于高盐沼泽栖息地初级生产力的样本消费者是sora（Porzana carolina）。二源和三源混合模型将大米草确定为鱼类的主要有机物质来源，以及无脊椎动物和蒂华纳河口的轻足拍板轨的大型藻类的主要有机物质来源。在圣迪吉托泻湖，一个缺乏大米草的系统，大型藻类和微藻类的输入支持鱼类。 subterminalis、Monanthocloe littoralis、污水来源的有机物和悬浮颗粒有机物被演绎排除为对食物网的主要、直接影响。这些系统中盐沼-河道联系的论证证实，这些栖息地应作为一个单一的生态系统进行管理，并且为濒危鸟类和其他生物群恢复潮间带沼泽与沿海鱼类种群的增加是相容的；迄今为止，这些目标一直被认为是相互竞争的目标。
Carbon, nitrogen, and sulfur stable isotopes were used to characterize the food webs (i.e., sources of carbon and trophic status of consumers) in Tijuana Estuary and San Dieguito Lagoon. Producer groups were most clearly differentiated by carbon, then by sulfur, and least clearly by nitrogen isotope measurements. Consumer15N isotopic enrichment suggested that there are four trophic levels in the Tijuana Estuary food web and three in San Dieguito Lagoon. A significant difference in multiple isotope ratio distributions of fishes between wetlands suggested that the food web of San Dieguito Lagoon is less complex than that of Tijuana Estuary. Associations among sources and consumers indicated that inputs from intertidal macroalgae, marsh microalgae, andSpartina foliosaprovide the organic matter that supports invertebrates, fishes, and the light-footed clapper rail (Rallus longirostris levipes). These three producers occupy tidal channels, low salt marsh, and mid salt marsh habitats. The only consumer sampled that appears dependent upon primary productivity from high salt marsh habitat is the sora (Porzana carolina). Two- and three-source mixing models identifiedSpartinaas the major organic matter source for fishes, and macroalgae for invertebrates and the light-footed clapper rail in Tijuana Estuary. In San Dieguito Lagoon, a system lackingSpartina, inputs of macroalgae and microalgae support fishes.Salicornia virginica,S. subterminalis,Monanthochloe littoralis, sewage- derived organic matter, and suspended particulate organic matter were deductively excluded as dominant, direct influences on the food web. The demonstration of a salt marsh–channel linkage in these systems affirms that these habitats should be managed as a single ecosystem and that the restoration of intertidal marshes for endangered birds and other biota is compatible with enhancement of coastal fish populations; heretofore, these have been considered to be competing objectives.