The contributions of habitat-forming species to the biodiversity and ecosystem processes of marine and terrestrial ecosystems are widely recognized. Aquatic plants are considered foundation species in shallow ecosystems, as they maintain biodiversity and sustain many ecosystem functions such as primary production and respiration. Despite the increasing amount of biodiversity-ecosystem functioning experiments in seagrass habitats, the effects of benthic variability on ecosystem functioning are rarely investigated across spatially variable aquatic plant habitats. Here, we quantitatively link seasonal variability in seafloor metabolism (i.e. gross primary production and community respiration) with major benthic community components (i.e. microphytobenthos, aquatic plants and macrofauna) across a structural complexity gradient of habitat-forming species (in terms of shoot density and biomass), ranging from bare sand, to a sparse mixture of plants to a dense monospecific seagrass meadow. The increasing complexity gradient enhanced the magnitude of the relationships between benthic community and seafloor metabolism. The daily average seafloor metabolism per season at the bare site was similar to the sparse site, highlighting the role of microphytobenthos for seafloor metabolism in shallow unvegetated sediments. The contribution of the associated macrofauna to the seafloor respiration was similar to the aquatic plant community contribution. Infauna was the main macrofaunal component significantly explaining the seasonal variability of seafloor respiration. However, benthic community-metabolism relationships were stronger within the plant community than within the macrofauna community (i.e. steepest slopes and lowest p-values). Understanding these relationships are a priority since climate change and biodiversity loss are reducing habitat complexity around the world, jeopardizing valuable ecosystem functions and services.

形成栖息地的物种对海洋和陆地生态系统的生物多样性和生态系统过程的贡献已得到广泛认可。水生植物被认为是浅层生态系统中的基础物种，因为它们维持生物多样性并维持许多生态系统功能，例如初级生产和呼吸。尽管海草生境中生物多样性-生态系统功能实验的数量不断增加，但很少在空间上变化的水生植物生境中研究底栖可变性对生态系统功能的影响。在这里，我们将海底新陈代谢的季节性变化（即初级生产总值和群落呼吸）与主要底栖生物成分（即微型底栖动物，水生植物和大型动物）形成栖息地的物种（就枝条密度和生物量而言）的结构复杂性梯度，范围从裸露的沙子到稀疏的植物混合物再到密集的单特异性海草草甸。复杂性梯度的增加增加了底栖生物群落与海底代谢之间关系的强度。在裸露的地方，每个季节每天的平均海底代谢与稀疏站点相似，这突显了微植物底栖动物在浅层无植被沉积物中对海底代谢的作用。相关大型动物对海底呼吸的贡献与水生植物群落的贡献相似。Infauna是主要的大型动物组成部分，可极大地解释海底呼吸的季节性变化。然而，p值）。由于气候变化和生物多样性的丧失正在降低全世界栖息地的复杂性，从而危及宝贵的生态系统功能和服务，因此了解这些关系是当务之急。