Pulsatilla vulgaris (L.) Mill. - Plantlife

In England Pulsatilla vulgaris is confined to moderately steep south to southwest facing slopes
where insolation is high, soils are shallow and competition from other species is restricted
(Fig. 8). Most populations are confined to escarpment grasslands of Chalk and Jurassic
limestone (Fig. 9c, 9e-g, 9i-l) but it also occurs in similar grasslands in old quarries (e.g.
Hornsleasow Roughs, Fig. 9b) and on ancient earthworks such as hill-forts (e.g. Ravensburgh
Castle, Fig. 9d) and Anglo-Saxon dykes (e.g. Devil’s Dyke, Fig. 9a). In old quarries and on
earthworks plants tend to occur on relatively shallow slopes on a greater range of aspects,
although even on these plants are generally found on more southerly aspects than those facing
northwards (Wells & Barling, 1971). Plants usually occur at greatest density on the steepest
(mid) part of the slope where soils are shallowest, rather than on deeper soils at the top or
bottom. For example, Wells & Barling (1971) recorded densities of 7.5 plants m -1 where the
soil was 5 cm deep but only 1.2 plants m -1 at soil depths greater than 100 cm (Fig. 7a).
(a) (b)
Figure 8 – The aspect (a) and slope (b) of Pulsatilla vulgaris populations in England. The
figures include values for the 29 populations included in Wells & Barling (1971) and five
populations discovered since then.
With the exception of Hildersham Furze Hills (see below), Pulsatilla vulgaris occurs on shallow
(5-15(25) cm) drought-prone calcareous rendzinas over chalk and limestone with relatively
high surface soil pH (average 7.5; range 7.1-7.8; Table 6). These soils are very friable and
porous with high contents of calcium carbonate (mean 67%; range 34-91%), organic matter
(mean 15%; range 8-22%) and total nitrogen (mean 0.5%; range 0.3-0.7%) (Wells & Barling,
1971). All are base-saturated with calcium being the most abundant cation present (320-830
mg 100g -1 dry soil) with other mineral nutrients, especially phosphorous, occurring at low
levels (Table 6). The clay/silt/sand fractions of these soils is also low (