Plant senescence for ecologists: precision in concept, scale, and terminology

Plant scientists, conservationists, and land managers have expressed a need for more research into causal mechanisms behind whole-plant senescence and mortality, especially where increased rates and incidence of forest decline are projected owing to climate change. However, these disciplines use the terminology of senescence in different ways, and this impedes communication between them. We highlight three common difficulties with senescence terminology as used in the ecological literature and propose some solutions. Specifically, we recommend (1) distinguishing between physiological and demographic senses of the term “senescence”; (2) discarding the qualifiers “exogenous” and “endogenous” as applied to disturbances that can contribute to senescence; and (3) using care in attributing mortality of individual woody perennials to senescence.