Allochthonous subsidies to marine ecosystems have mainly focused on biogeochemical cycles, but there has also been recent interest in how terrestrial carbon (C) influences marine food webs. In the Baltic Sea, pine (Pinus sylvestris) pollen is found in large amounts in shallow bays in early summer. Pollen is a significant C-source in freshwater ecosystems and may also be important in coastal food webs. We examined the consumption of pollen and autochthonous resources by benthic invertebrates in shallow bays of the Baltic Sea. We used stable isotopes to estimate diets and reconstructed consumer-resource networks (food webs) for grazers and particulate organic matter (POM)-feeders to compare how these different guilds used pollen. We found that P. sylvestris pollen was consumed in small amounts by a variety of animals and in some cases made up a sizeable proportion of invertebrates' diets. However, invertebrates generally depended less on pollen than other resources. The degree of pollen consumption was related to feeding traits, with generalist invertebrate grazers consuming more pollen (> 10% of diet) than the more specialist POM-feeders (< 5% of diet contributed by pollen). POM-feeders may consume additional microbially-degraded pollen which was not identifiable in our model. We suggest that pollen is a small but substantial allochthonous C-source in shallow bay food webs of the Baltic Sea, with the potential to affect the dynamics of these ecosystems.

中文翻译：

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洒金尘：松花粉作为波罗的海沿岸食物网中的碳源

对海洋生态系统的异地补贴主要集中在生物地球化学循环上，但最近也对陆地碳 (C) 如何影响海洋食物网产生了兴趣。在波罗的海，初夏时在浅海湾大量发现松树（ Pinus sylvestris ）花粉。花粉是淡水生态系统中重要的碳源，在沿海食物网中也可能很重要。我们检查了波罗的海浅海湾中底栖无脊椎动物对花粉和本土资源的消耗。我们使用稳定同位素来估计饮食，并为食草动物和颗粒有机物 (POM) 喂食者重建消费者资源网络（食物网），以比较这些不同行会如何使用花粉。我们发现P. sylvestris各种动物少量食用花粉，在某些情况下，花粉在无脊椎动物的饮食中占相当大的比例。然而，与其他资源相比，无脊椎动物通常较少依赖花粉。花粉消耗的程度与摄食特性有关，一般无脊椎动物食草动物消耗的花粉更多（> 10% 的饮食）比更专业的 POM 饲养者（< 5% 的饮食由花粉贡献）。POM 喂食器可能会消耗额外的微生物降解花粉，这在我们的模型中无法识别。我们认为花粉是波罗的海浅湾食物网中一种小而重要的异地碳源，有可能影响这些生态系统的动态。