Brown meets green: light and nutrients alter detritivore assimilation of microbial nutrients from leaf litter

In aquatic detrital-based food webs, research suggests that autotroph-heterotroph microbial interactions exert bottom-up controls on energy and nutrient transfer. To address this emerging topic, we investigated responses to light treatments during Liriodendron tulipifera litter decomposition fed the caddisfly larvae Pycnopsyche sp. We measured litter-associated algal, fungal, bacterial biomass production. Microbes were also labeled with 14C 33P trace distinct carbon (C) phosphorus (P) supporting assimilation incorporation (growth). Litter-associated algal fungal production rates additively increased higher availability. Incorporation of P did not differ across diets, except for efficiency slower-turnover low-nutrient, shaded litter. On average, assimilated C more efficiently than or C, incorporated C. Due high biomass, fungi supported 89.6–93.1% growth, compared 0.2% 3.6% by bacteria algae. Overall, most in Our findings affirm others' regarding extend into trophic transfer nutrients through detrital webs.