A Cross-community Approach to Energy Pathways Across Lagoon Macroinvertebrate Guilds

Abstract

Decomposition processes are a major source of energy in lagoon ecosystems, but compared to primary production, little quantitative information is available on their relative importance for energy pathways within lagoon food webs. Here, the ability of cross-community scaling relationships (CCSRs) to describe energy pathways in macroinvertebrate guilds from size-specific density estimates was tested in order to determine whether CCSRs distinguish between i. predators and prey guilds in energetic terms, ii. suspension and deposit feeders in terms of their energy sources, iii. deposit feeder sub-guilds (i.e. scrapers/shredders and gathering collectors), and iv. phyto-benthic habitats in terms of their influence on energy pathways. CCSRs differentiated predator from prey guilds, with the size-specific density of prey being one order of magnitude higher than that of predators, and deposit from suspension feeder guilds, to a similar degree. CCSRs differentiated vegetated from non-vegetated benthic habitats, with higher size-specific density in the former than in the latter, while they did not differentiate large- from small-particle feeders. Based on simple data collection and widely available data on 15 Mediterranean and Black Sea lagoons, CCSRs seem to be able to quantitatively describe energy pathways in benthic macroinvertebrate communities, expanding our knowledge of biodiversity drivers in lagoon ecosystems.