ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Litter, plant Litterfall, plant litter, leaf litter, tree litter, soil litter, or duff, is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. Wikipedia https://en.wikipedia.org/wiki/Plant_litter Added to support Critical Zone Observatory (CZO) data use cases.