276 



PLANT SOCIOLOOY 



south, J. oxycedrus and J. macrocarpa are about the only trees which 

 manage to attain their maturity in a pasture and to maintain them- 

 selves — thanks to their spines. They form either a parklike, open 

 landscaping of the heath regions (Fig. 16) or a dense, low scrub. In 

 Obervinschgau, between Schlanders and Mais (800 to 1,200 m.), 

 intensive goat pasturing has transformed the forest of the south slopes 

 for many miles into unsightly Juniperus thickets, which are quite as 

 forbidding as the Mediterranean thorn scrub. Likewise, the southern 

 stands of J. oxycedrus are due to grazing (Fig. 142). 



Fig. 142. — Sheep-trampled, deserted farm land near Montpellier. Juriiperus oxycedrus 

 enters the Thymus vulgaris fades. {Photo by P. Keller and Braun-Blanquet.) 



Resting places of game and cattle are marked by a rank growth of 

 tall, juicy ruderal herbs, characteristic of soils of mesic deciduous 

 forests. In the mountains of Europe the genera Rumex, Aconitum, 

 Senecio, Cirsium and in lower altitudes species of Carduus, Onopordon, 

 Cynoglossum, Urtica rise in tall thickets on places frequented by cattle 

 and game. The meadow communities of the high mountains are very 

 different from this luxuriant dung vegetation. 



With excessive amounts of manure the soil is stimulated to very 

 great bacterial activity. This explains the rich development of nitro- 

 philous dung plants which are able to store considerable quantities of 

 nitrates in their tissues. According to the ability of the individual 



