The object of the studies conducted in the years 1987-1991 was the isolated population of Senecio rivularis in Roztocze National Park, southeastern Poland, i.e. at the northeastern border of the species’ geographical distribution. Studies aimed to learn about the probability and rate of attaining succesive developmental stadia of individuals in different parts of the population areal, and how the development rate of individuals affects the increasing of population abundance, density and spatial structure.
Keywords: Senecio rivularis, demography, isolated population, Poland.