Klemow, Kenneth M. 1987. DEMOGRAPHY OF THE CLONAL PERENNIAL HIERACIUM FLORENTINUM IN AN UNPRODUCTIVE HABITAT. Contributed paper: Ecological Society of America meeting. Abstract: Bulletin of the Ecological Society of America 68:341-342.
Yellow hawkweed (Hieracium florentinum L. (Asteraceae)) is one of the dominant herbaceous species naturally colonizing a 50-year-old, abandoned limestone quarry near Syracuse, New York. Populations of H. florentinum were monitored on two contrasting sites (one sparse, the other dense) from 1976 to 1981 to determine the direction and rate of population flux, and the relative importance of seedlings vs clonally produced rosettes (ramets) to population maintenance. On both sites, the total density of rosettes remained essentially constant during the six-year observation period. Densities did vary considerably both within and between years, however, due to flushes of emergence. The number of seedlings that appeared was twice that of the ramets. However, ramets exhibited much higher rates of survival to flowering. Population maintenance of H. florentinum in the Syracuse quarry depended almost exclusively on recruitment and survival of ramets to replace older individuals that die. Demographic attributes of H. florentinum will be compared to those of the other co-dominant herbaceous species.