Fig. 1: Schematic diagrams illustrating the main hypotheses concerning the roles of litter-mixing, decomposition stages, and benthic faunal communities in controlling litter-mixing effects on decomposition.

In particular, we hypothesized the following: (1) Increased initial litter species richness enhances faunal abundance in the early stage (Stage 1). This trend diminishes during the late stage (Stage 2) when macroalgae disappears (see a–c). (2) The decomposition rates of seagrass are negatively related to both litter species richness and macroalgal dominance during Stage 1 because of the resource selection of fauna favouring macroalgae (see d). (3) The decomposition rates of seagrass are positively related to both litter species richness and faunal presence in the absence of macroalgae during Stage 2 (see e).