ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Respiration, ecosystem Gross carbon dioxide production by all organisms in an ecosystem. Ecosystem respiration is the sum of all respiration occurring by the living organisms in a specific ecosystem. Originally from the CUAHSI HIS VariableNameCV. See: http://his.cuahsi.org/mastercvreg/edit_cv11.aspx?tbl=VariableNameCV.