SOME VEGETATION TYPES AT HIGH ALTITUDES. 55 



{Rhododendron hirsutum). The droppings of the cattle on these 

 pastures encourage the growth of plants, so that a luxuriant 

 rank growth is obtained in places. 



Of the many representatives constituting this widespread 

 association, the following examples may be mentioned: — Carex 

 7iigfa, C. sempervirens, Phleum alpinum, Poa alpina var. 

 vivipara, Potoitilla aurea, Viola calcarata, Pedicularis verti- 

 cillata, Helianthemum alpestre, Veronica aphylla, Nardus siricta^ 

 Liizula lutea, Trifolium alpinum. Ranunculus montanus, R. 

 pyrenaicus, Myosotis alpestris, Campanula barbata, Ligusticum 

 mutellifia, Euphrasia 7ninima, Leontodon pyrenaicus, Festuca 

 Halleri, Gentiana excisa, Crepis aurea, etc. 



Summary. 



The forest flora of the district under consideration may be 

 grouped under several distinct associations, which arrange 

 themselves into the following succession : — 



1. Mountain pine (bush form). This forms a dwarf type of 



forest, which occupies the upper limits of tree-growth 

 and occurs also in wash-out channels on the slopes. It 

 has an irregular and somewhat restricted distribution. 



2. Mountain pine (erect form). High-forest is produced at 



a lower level by the erect form of the mountain pine. 

 In Val Cluoza its distribution is somewhat restricted, 

 whereas in Spoltal it has the widest distribution of all 

 the forest formations. 



3. Larch and Cembran pine. A mixed forest type containing 



larch and Pitius Cembra succeeds the last association, 

 and marks the beginning of mixed forests. The above 

 two species occur at the upper limits of the zone, while 

 larch alone descends to the lower limits, and is found 

 there in association with spruce and Scots pine. These 

 three species form the mixed forest type of the district. 

 This association has the widest distribution of all. 



4. Grazing forest (larch). This is a compromise between 



agricultural and forest land, and its distribution is 

 restricted. It assumes a strip formation extending 

 along the bottom valley slope and skirts the forest 



