|| 要旨トップ | 目次 |||日本生態学会第70回全国大会 (2023年3月、仙台) 講演要旨
一般講演（口頭発表） A01-03 （Oral presentation）
Dissolved nutrients released from leaf litters support and alter the structure of freshwater food webs. Dissolved organic carbon (DOC) leached from leaf litters is an allochthonous carbon source to heterotrophic bacteria, which enhances freshwater detritus food chain. In addition to DOC, inorganic phosphorus (P) and nitrogen (N) nutrients and micronutrients are released from leaf litters during the leaching process. These nutrients instead support phytoplankton primary production and enhances the grazing food chain. In this study, we investigated how leachates of leaf litters with distinct stoichiometry influence freshwater microbial food web by incubating microbial community from lakes in two broadleaf and two coniferous litter leachates. We also tested the limitation of micronutrient in litter leachates. We found high total microbial biomass in coniferous litter leachate, which contains high DOC but low N and P nutrients. Coniferous litter leachate also support relatively higher heterotrophic biomass. With micronutrient amendment, light-dependent autotrophic biomass increases while micronutrient effect is not always positive to heterotrophic biomass. This indicates that micronutrient limitation to heterotrophic and autotrophic microbial growth is different. We conclude that the stoichiometry of leaf litter leachate influences microbial food web structure and heterotrophic/autotrophic production in freshwater food webs.