Tropical seagrasses support abundant and diverse epiphytic microalgae that form the base of seagrass food webs. To help better understand the influence of structural variability of tropical seagrass meadows on associated microalgal epiphytes, we quantified the relative abundance and distribution of epiphytic microphytes in subtidal meadows of Thalassodendron ciliatum with varying seagrass canopy structure, using pigments and fatty acid (FA) profiling. We observed significant differences in microalgal epiphytic communities (diatoms and Rhodophyta) among four seagrass meadows, which was best explained by seagrass leaf surface area. Contrary to expectations, seagrass meadows with lower leaf surface area supported higher relative epiphytic microphyte abundance than those with higher leaf surface area. These results increase understanding of how spatial variability of structural components in seagrass meadows can influence their functional components, with implications on the availability to primary consumers.

热带海草支持形成海草食物网基础的丰富多样的附生微藻。为了更好地了解热带海草草甸的结构变异性对相关微藻附生植物的影响，我们量化了拟南芥纤毛潮间带草甸附生微植物的相对丰度和分布使用颜料和脂肪酸（FA）轮廓分析具有不同海草冠层结构的材料。我们观察到四个海草草甸之间的微藻附生群落（硅藻和红藻植物）存在显着差异，这最好用海草叶表面积来解释。与预期相反，叶表面积较低的海草草甸比叶表面积较高的草地具有更高的相对附生微植物丰度。这些结果使人们更加了解海草草甸中结构性成分的空间变异性如何影响其功能性成分，从而影响主要消费者的可利用性。