Long-term stoichiometry and fates highlight animal egestion as nutrient repackaging, not recycling, in aquatic ecosystems

摘要: Summary Animal defecation, or egestion, is a pronounced transformation of organic matter in many ecosystems. However, because egesta have been presumed recalcitrant and low nutrient, their significance variability as an animal nutrient flux aquatic settings – especially relative to mineralization via excretion are poorly known. We compared carbon (C), nitrogen (N) phosphorus (P) dynamics over short- long-term (up 107 days) microbial decomposition from the shredders Allocapnia spp., Lirceus spp. Tipula fed low- high-P content Platanus occidentalis litter investigate roles dynamics. Tipula produced N P deplete higher N : P Allocapnia, diets increased low-P diets. Despite measurable C losses decomposition, these differences persisted through showing diet species control both immediate properties egested particles. Egesta switched between uptake release dissolved ammonium during exhibited consistent net nitrate–nitrite. Across diets, lower tended exhibit greater inorganic N, suggesting enrichment drove stronger demand by decomposer microbes. Shredder stable contents long term and, counter assumptions that they negligible minor sources, can be strong, extended sinks nutrients. Future studies should consider contrasts fluxes excretion, which facilitates recycling mineralization, vs. slows repackaging create nutrients. A lay summary available for this article.