Table 1.
Growth and reproductive parameters of Hieracium pilosella L. used for the simulation model from demographic measurements in calcareous grassland in NW Switzerland and from an experiment on germination probability of seeds and seedling survival at the same site (Keller, 1997)
| Parameter | Value | Source of data (Keller, 1997) |
| Growth rate of vegetative rosettes from March to June (mm d–1) | 0·16 | 609 rosettes measured |
| Fraction of reproducing rosettes with: | 225 rosettes flowering | |
| one flower head | 88 % | |
| two flower heads | 12 % | |
| Percentage of reproducing rosettes with: | 230 rosettes with stolons | |
| one stolon | 46 % | |
| two stolons | 45 % | |
| three stolons | 9 % | |
| Ripe seeds per flower head (mean ± s.d.) | 54 ± 23 | Counts of 30 flower heads |
| Length of stolons (cm, mean ± s.d.) | 4·8 ± 6·4 | 193 stolons measured |
| Probability of a rosette flowering within a year | 0·36 | Fate of marked rosettes (n = 609) |
| Flowering probability of a rosette with diameter | From a frequency distribution of | |
| 3 cm | 0·08 | flowering probability depending flowering probability depending |
| 5 cm | 0·65 | on diameter of rosettes |
| Probability of establishment of a rosette produced from a stolon | 0·58 | Fate of observed stolons (n = 374) |
| % Germination of seeds in undisturbed grass vegetation (mean ± s.d.) | 2·4 ± 4·3 | Mean of 30 replicates in small plots (8 × 8 cm) |
| Seedling mortality until autumn (mean ± s.d.) | 0·54 ± 0·38 | |
| % Seedling recruitment in plots with open soil prone to drought | 0 | No seedlings in such plots |
See Materials and Methods for more details.