Stochastic simulation of patch formation by Hieracium floribundum (Compositae) in abandoned pastureland

Plants marked with toothpicks were observed over a period of 2 years to determine recruitment, growth, and death rates for hawkweed patches present in an abandoned pasture in southern Ontario. All rates were affected by patch density, although the effect of density differed for seedlings and rosettes. These field data were used in a mathematical model to simulate the addition of seedlings and rosettes to a newly formed, low-density (160/m2) patch. Simulationresults suggested that it would take at least 25 years for a patch to reach a steady-state density of about 3300 rosettes plus seedlings per square metre.