Dynamics of Plantago maritima along a distributional gradient: A demographic study

Abstract

The dynamics of a Plantago maritima population was studied along a distributional gradient on a sea shore meadow during four years. The dynamics of the population varied along the gradient. In the lower parts there was a high flux with high mortality due to flooding but also a higher reproductive effort and good establishment. In the upper parts the flux was slower with lower reproductive effort and lower seedling success but instead longer lifespans. Population growth in these upper areas was primarily restricted by competition for light which prevented flowering and lowered the seedling success. Both cover values and the number of species decreased seawards and consequently the strength of competition. Simultaneously the risk of flooding increased. Thus the density peak was found at the intersect of these two variables. The plants showed differences in behaviour along the gradient in reproductive effort, growth rate, phenology etc. Whether this variation was phenotypical or genotypical is not known.