Age matters: Demographic senescence in the moss Polytrichastrum formosum

Abstract

Demographic senescence, a decrease in survival and/or fertility with age, has been shown to occur in all investigated mammals and birds, which are the most well-studied taxa in this regard (Jones et al., 2014).Historically, the main focus of plant demography has been on size and/or life-cycle stage, as these are considered to be accurate predictors of vital rates in many or most plants (Caswell, 2001).However, recent research indicates that age also matters and that there is substantial variation in how age affects vital rates such as survival, reproduction and growth (Edelfeldt, Bengtsson, et al., 2019;Roach & Smith, 2020). In some species, survival shows no significant relationship with age or may increase towards higher ages (Edelfeldt,

Actuarial senescence progresses similarly across sites and species in four boreal orchids

“…Current empirical evidence, however, suggests that many different ageing patterns exist in plants. Actuarial senescence, defined as increasing mortality with age (Hamilton, 1966; Kirkwood, 1977; Kirkwood & Holliday, 1979), hereafter senescence , has been identified in a range of species (Roach & Smith, 2020; Silvertown et al., 2001), including both short‐ (Picó & Retana, 2008; Roach et al., 2009) and long‐lived perennial herbs (Edelfeldt et al., 2019; Silvertown et al., 2001), as well as some tree species (Baudisch et al., 2013) and a moss (Tholstrup et al., 2021). In contrast, several other species have been documented to display mortality patterns suggesting negligible (i.e.…”