Hippophae rhamnoides

Hippophae rhamnoides L.

Sea-buckthorn

Status: scarce

This is a thorny deciduous shrub or small tree of less mobile dune sand and occasionally soft sea cliffs. In its coastal habitat, it grows most vigorously where it is sheltered from the wind, in places such as dune hollows and the leeward or landward side of ridges rather than on dune crests. It is intolerant of shade and does not penetrate into woods and forests, except locally in clearings and by trackways. Plants which were present before Hippophae invades (e.g. Ammophila arenaria, Festuca rubra) often persist for a period under the canopy. The shrub later becomes dominant, forming dense stands in which Urtica dioica often grows (Pearson & Rogers 1962). It is often planted in gardens or amenity plantations and introduced plants are sometimes found on river sand and gravel banks inland.

Initial invasion may be by seed because, though the species is dioecious, fruiting can be prolific and birds can transport the seed some distance. Germination requires a cold pre-treatment (2 to 5 °C) (Ranwell 1972) but such a need is generally met in early winter and viability can be high. Seeds can withstand at least l2 weeks at a temperature of -20 °C and still remain viable. Young plants can withstand some accretion, as long as they are not completely buried. The mature plant does not show any signs of frost damage. Established plants produce vigorous suckers.

H. rhamnoides is considered native only on the eastern coast of England. Introductions and the natural spread from introduced populations have now obscured the native range. It was seen initially as a possible solution to problems associated with dune erosion, but more recently H. rhamnoides has given cause for concern in some dune sites, presenting a real threat to botanical interest. In some areas steps have been taken to eradicate this species.

It occurs along the coast of north-west Europe, Norway and the Baltic. It is also found on the shores of the northern Mediterranean, the Black and Caspian Seas and Lake Baikal. Its inland distribution embraces most of the major mountain ranges from the Pyrenees and Alps to the Caucasus, Carpathians and the Himalayas, occurring as far east as southwest China (Pearson & Rogers 1962). 

H. rhamnoides was widespread in Britain in the Late Glacial in both coastal and inland sites. With the spread of forest it became restricted to coastal sites. In Scandinavia it has a similar history, but there it survives in montane refugia as well as in coastal sites (Godwin 1975).

H. Ainsworth