ZONATION 



The recognition of vegetation zones dates from Toume- 

 fort (I7J7), who found that, while the plants of Armenia 

 occupied the foot of Mount Ararat, the vegetation of the 

 slopes above contained many species of southern Europe: 

 still higher appeared a flora similar to that of Sweden, and 

 on the summit grew arctic plants, such as those of Lapland. 

 Linne (I75t) generalised this idea in the dictum, ^'Planted 

 diversce indicant altitudinem perpendtcularem terrce." Raimond 

 (J80I) studied the vegetation of the Pyrenees, and estab- 

 lished the characteristic zones. A forest belt of Quercus 

 robur occurred on the lowermost slopes. This was bordered 

 by a zone of Fagus silvatica, and this in turn by Abies taxifolia, 

 and Taxus communis, which were replaced above by Pinus 

 silvestris and P. mugho. Above the forest ran a border of 

 thickets, consisting of Bhododendron^ Daphne, Salix, etc., and 

 beyond these, reaching to the snow cap, lay a zone of herbs 

 and lichens, Oentiana, Primula, Saxifraga, etc. Hamboldt 

 and Bonpland (1805:37) employed the word region to designate 

 the zones of mountains, restricting zone to the vegetation 

 belts determined by latitude : they were not entirely consist- 

 ent in their use of these terms, however. The results of 

 their study of the vegetation of the Andes were graphically 

 represented upon a chart of Chimborazo and Cotopaxi, in 

 which were indicated the regions, the principal species of 

 each and the variations of temperature, pressure and 

 humidity. Schouw (I823:J69) followed Humboldt and Bon- 

 pland in the use of zone and region, and further distinguished 

 the former as zones of latitude, and zones of longitude. A. 

 De CandoIIe (1855:248) discussed at length the question of 

 the upper and lower limits of mountain plants, first consid- 

 ering in a general way the influence of humidity, air and 

 soil temperatures, exposure, pressure, soil composition, etc. , 

 and then in a more detailed manner the distribution of the 



