title: Heterotrophy by plankton in three lakes of different productivity.
mesh_terms: D003624:Darkness; D004463:Ecology; D005618:Fresh Water; D007700:Kinetics; D008027:Light; D010933:Plankton / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D013460:Sulfur Isotopes
chemical_list: D013431:Sulfates; D013460:Sulfur Isotopes