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

Whole-plant senescence, defined as a decrease in individual fitness as an organism grows older, has often been assumed to not occur in plants; however, it has now been detected in a range of plant taxa. Still, reported senescence patterns vary substantially, and it remains unknown how consistent patterns are within phylogenetic groups and how they may be affected by environmental factors. Plants show a high diversity in life-history traits within phylogenetic groups and environments, but shared traits amongst related species are also common, making both diverse and similar patterns probable. Here, we explore how mortality changes with advancing age in four closely related species (Dactylorhiza incarnata, D. lapponica, D. maculata, and Gymnadenia conopsea) across two sites in Norway: the coastal Nordmarka and inland Sølendet. Using data collected over 34 years, following more than 2500 individual plants, we conduct Bayesian survival trajectory analysis to assess mortality age-trajectori..., , , # Actuarial senescence progresses similarly across sites and species in four boreal orchids Year of sexual maturity and death for four boreal orchids at two sites in Norway, illustrating actuarial senescence for all species-site combinations. ## Description of the data and file structure First year of flowering and year of death for four orchid species at two sites. The dataset includes 8 columns: Birthyear = the year of first observation (has the value zero if already flowering in the first year, 1981); Deathyear = the first year of absence (has the value zero if present the last year, 2015); Remaining columns indicate species (D. incarnata, lapponica or maculata, or G. conopsea), or site (S or N); 0 indicates an observation is not for the given species or site, 1 indicates an observation is for a given species or site.