286 RI K A RD STERNER 



continental climates. In maritime districts it is replaced by grass heaths poor in 

 herbs and dwarf-shrub heaths. In Northern Europe it is almost entirely absent. 

 There the sandy areas are occupied by pine forests, rich in lichens and dwarf- 

 shrubs. Hence it is chiefly between the sand-steppes of South-Eastern Europe, 

 the pine-forests of Northern Europe and the heaths of Western Europe that this 

 psammophilous vegetation is distributed. It reaches its richest development in 

 Sarmatian regions. Hence I will call it Sarmatian sand-grass heath. 



We often find this or a similar sand-grass heath forming the ground vegetation 

 in thin pine forests on sandy soil. In Middle Russia, especially in the zone 

 of the » Transition Steppe», this vegetation type seems to have a wide distri- 

 bution (e. g. Flerov 1902, e. g. pp. 229, 245, 255; 19 10, e. g. the plant lists 

 459, 562, and 762; Sukaczev 1902 p. 159, Taliev 1896, 19O4, Tanfiljev 1894). 



According to Drude (1902), Pax (19 15), Jannike (1889), Scholz (1905), Graebner 

 (1901) sandy areas in the eastern and southern parts of the North German plain 

 are to a great extent occupied by herbaceous sand-grass heaths. To the west 

 and near the coast they arc replaced by grass heaths poor in herbs, Aira flexuosa- 

 and Nardus stricta-associations and ericaceous heaths (cf. Graebner 1. c, pp. 147 

 and 217, and Preuss 1912). In the west they seem to reach as far as the region 

 around the lower Elbe (Graebner 1. c, Drude 1. c, p. 450). 



This vegetation-type is represented in the vegetation of South Sweden, about 

 which further particulars will be given below. To judge from statements in 

 Hayek (1914) and Laus (1910), it seems to have a great distribution in northern 

 Galicia, in Moravia and in Bohemia. In Eastern Balticum it is principally re- 

 presented as ground-vegetation in a thin pine-forest (cf. Lehmann 1895, p. 64 

 and Meinshausen 1878, p. xii). In Poland it is widely distributed (Pax 191 8). 



I have not been able to decide whether these herbaceous sand-grass heaths 

 are also found in western Europe. Some species of the Sarmatian sand-gra.<=s 

 heaths have localities in these parts, especially in the sandy areas in Central 

 France on the middle Loire (Veronica spicata, Phleum Boehmeri, Carcx praecox 

 Schreb. and ligerica, Koeleria glauca, and Peucedanum oreoselium.; cf. Sterner 

 1921 a, p. 213). 



Besides the types of plant communities just mentioned, the pure colo7iy vege- 

 tation on rocky cliffs, steep sandy or clayey slopes, and rock)- pavements be- 

 comes an important place of resort for steppe species. In North Germany, steep 

 slopes exposed to the south in the » Strom- or Urstrom-Talcr» are very rich in 

 steppe species (Loevv 1879, Preuss 191 2, Scholz 1905). According to Drude 

 (1902), the colony vegetation on rocky pavements and rocky cliffs in Central 

 Germany houses many steppe species among its rich licrh tlora. The outposts 

 of the steppe species to the west would in many cases seem to consist exactly 

 of such localities. 



