Coastal vegetated habitats maintain highly diverse communities, where the contribution of macrophyte production is significant for macroinvertebrate primary consumers. In the brackish-waters of the Baltic Sea, the taxonomical diversity of different macrophytes includes both marine and limnic species. To study the basal food-web differences of two key vegetated habitat types, either dominated by a perennial brown macroalgae (Fucus vesiculosus) or by angiosperm plants, ¹³C and ¹⁵N compositions of different primary producers and macroinvertebrate consumers were examined, and their diets were estimated by Bayesian mixing models. Carbon isotope diversity of primary producers was high especially in the hard-bottom Fucus-dominated habitats, which was also reflected in a larger consumer isotope niche. However, consumer isotope niche among sites was similar within the same habitat type. Our models indicated that the perennial macrophyte dietary median contribution was about 25 % for deposit feeders and omnivores in both habitat types, while epigrazers preferred filamentous algae (30−60 %). The niche positions of the abundant clams L. balthica, M. arenaria and C. glaucum differed between the two habitats, but they showed only small (<10 % units) differences in their macrophyte dietary contributions. The isotopic compositions of the dominating primary producer assemblage reflected significantly in the isotope niche structure of the associated primary consumers.

沿海植被栖息地维持着高度多样化的群落，其中大型植物生产的贡献对大型无脊椎动物的主要消费者来说意义重大。在波罗的海的咸水中，不同大型植物的分类多样性包括海洋和湖泊物种。为了研究以多年生棕色大型藻类（Fucus vesiculosus）或被子植物为主的两种主要植被栖息地类型的基础食物网差异，研究了不同初级生产者和大型无脊椎动物消费者的¹³ C 和¹⁵ N 成分及其饮食由贝叶斯混合模型估计。初级生产者的碳同位素多样性很高，尤其是在硬底墨角藻中-占主导地位的栖息地，这也反映在更大的消费同位素生态位上。然而，在同一栖息地类型内，站点之间的消费者同位素生态位是相似的。我们的模型表明，两种栖息地类型的沉积物饲养者和杂食动物的多年生大型植物饮食中值贡献约为 25%，而食草动物更喜欢丝状藻类 (30-60%)。两个栖息地之间丰富的蛤蜊L. balthica、M. arenaria和C. glaucum的生态位位置不同，但它们的大型植物饮食贡献仅显示出很小（<10% 单位）差异。主要初级生产者组合的同位素组成显着反映在相关初级消费者的同位素生态位结构中。