Matrix composition and patch edges influence plant-herbivore interactions in marine landscapes

The functioning of ecosystems can be strongly driven by landscape attributes. Despite its importance, however, our understanding of how landscape influences ecosystem function derives mostly from species richness and abundance patterns, with few studies assessing how these relate to actual functional rates. We examined the influence of landscape attributes on the rates of herbivory in seagrass meadows, where herbivory has been identified as a key process structuring these relatively simple systems. The study was conducted in three representative Posidonia oceanica meadows. The principal herbivores in these meadows are the fish Sarpa salpa and the sea urchin Paracentrotus lividus, and we hypothesised that differences in their interaction with landscape attributes would significantly influence herbivory rates. We measured herbivore abundance, herbivory rates, primary production and plant quality (C:N) in seagrass patches embedded either in rock or in sand (matrix attribute), in patches ei...

生态系统的功能运作可在很大程度上受景观属性调控。尽管其重要性已得到广泛认可，但当前学界对景观如何影响生态系统功能的认知，大多源自物种丰富度与个体多度格局的研究，鲜有探讨这些格局与实际功能速率之间关联的相关工作。本研究聚焦景观属性对海草床牧食速率的影响——已有研究表明，牧食过程是塑造这类相对简单生态系统的关键过程。本研究选取三处具有代表性的波西多尼亚海草（Posidonia oceanica）床开展实验。该海草床中的主要牧食者为萨尔帕鲷（Sarpa salpa）与帕氏海胆（Paracentrotus lividus），我们提出假说：二者与景观属性的相互作用差异，会显著影响牧食速率。我们针对两种基质属性（岩石基质与沙质基质）中的海草斑块，测定了牧食者多度、牧食速率、初级生产力以及植物碳氮比（C:N）等指标，实验斑块选自