Effects of increasing carrion biomass on food webs

Abstract

Carrion has well-documented effects on ecosystem processes, but how those effects change with increasing biomass, particularly with extreme amounts of carrion occurring during mass mortality events, is relatively unstudied. Traditional food web theory predicts basal resource availability is linked to bottom-up effects, which may support higher primary consumer biomass and food web diversity. Recycling efficiency increases with primary consumer diversity through niche differentiation and facilitation or potentially a sampling effect of having more species and functional groups. As carrion biomass increases, however, the carrion food web expands to include a more diverse community of secondary consumers that prey upon carrion obligates. With increases in vertical diversity of food webs, basal resource depletion generally decreases because primary consumers are preyed upon. Here we present empirical and previous literature evidence that indicates ecological interactions indeed change in response to increasing carrion biomass by increasing primary and secondary consumer diversity of species participating in carrion recycling. Our observations also indicate that rare and novel interactions emerge with extreme amounts of carrion. We pair previous literature with our observations to develop a theoretical basis for developing hypotheses and predictions concerning the relationship between carrion food webs and increasing biomass.