PhD Student University of Tokyo Kawasaki-shi, Kanagawa, Japan
Abstract: Rising temperatures and increasingly common extreme climate events are a leading cause of concern to conservation efforts globally. The ecological impacts of climate change have been documented for many species, but the evolution of life history traits is less well understood. The evolution of senescence (an increase in mortality or decrease in fecundity with age) under climate change is even less so. In a population of the long-lived orchid Cypripedium parviflorum that has shrunk by half in the past two decades, climate change is predicted to accelerate this decline. While predictions on the evolution of sprouting under climate change have been made for this population, predictions on the evolution of senescence have not. We created generalized linear mixed models (GLMMs) for all major vital rates using 23 years of demographic data and historical climate forecasts for the region surrounding the field site. Using these GLMMs and predicted atmospheric conditions from high-resolution climate projection models, we created age-by-stage matrix projection models for multiple future climate change scenarios. To assess the effects of climate change on the evolution of senescence, we used matrix sensitivity analysis of the deterministic population growth rate to changes in mortality and fecundity. We calculated selection gradients under multiple future climate projection scenarios to estimate the range of effects climate change will have on patterns of age- and stage-specific selection. Preliminary results show mortality is predicted to increase across all age-stages from now until the year 2100, and that previously documented patterns of age-specific mortality and fecundity leading to the evolution of senescence are more pronounced under climate change. Our analysis predicts the evolution of an important life history trait under multiple climate change scenarios, drawing attention to the importance of understanding the microevolutionary consequences of climate change.
