Population dynamics of the endangered plant Paeonia qiui (Paeoniaceae)

Paeonia qiui belonging to the family Paeoniaceae, is a perennial deciduous shrub, having ornamental and medicinal value. Recently the distribution of wild P. qiui has gradually reduced in China due to anthropogenic activites and the influence of various natural factors making its protection a great concern. A population of Paeonia qiui in the eastern Qinling Mountains was surveyed and created a static life table, survival curve, fecundity schedule and Leslie matrix model for analysis of numeric population dynamics. The P. qiui population experienced environmental screening and competitive self-thinning at ages <= 6 years and ages 9 to 15 years, respectively. The age of '11 years' is the physiological lifespan of P. qiui and the age of similar to 27 years is the lifespan limit. The survival curve was classified as a Deevey-I type, with a low net population growth rate of R-0 = 0.8005, an intrinsic rate of increase of r = -0.0205, and a finite rate of increase of lambda = 0.9797, indicating a declining population. Leslie matrix model simulation results indicated that the P. qiui population will decrease by about 78.8% within the next 30 years and that the current population mainly relied on asexual shoot regeneration for maintenance. The possible causes of endangerment of the P. qiui population are biological characteristics, population size, habitat conditions, and human disturbance. We recommend the establishment of protected areas in the original habitat of P. qiui to gradually restore population size, and individual plants valuable for research or other uses can be saved off-site.