CHAPTER II 

 ARCTIC PLANT FORMATIONS 



The Tundra. Characteristic features. Moss-tundra. Lichen-tundra. Moors. Oases. 

 The tundra in Taimyr according to Middendorff. The formations in Greenland. 

 Warming's classification. 



THE TUNDRA. 



Beyond the last stunted trees, so far as ice does not cover the ground, 

 the frigid desert or Tundra (Fig. 406) almost alone dominates arctic main- 

 lands and islands. Only in the less cold and therefore chiefly southern 

 tracts in the arctic zone, in more favourable localities a few less insignificant 

 formations exist ; for instance, willow-bushes and small meadows on river- 

 banks and in fjords, or even formations of dwarf shrubs, which consist of 

 a denser growth of the same evergreen, small-leaved, shrubby species as 

 appear singly in the tundra between mosses and lichens. 



Dwarfed growth, a distinctly xerophilous character, the predominance of 

 mosses and lichens, the incomplete covering of the ground, these features 

 are everywhere characteristics of the tundra. ' Its meagre plant-life is, how- 

 ever, by no means uniformly distributed. In some places mosses predomi- 

 nate, almost exclusively species of Polytrichum, in others lichens, apparently 

 according to the greater or less dryness of the soil, so that a distinction is 

 made between Moss-tundra or Polytrichum-tundra, and Lichen-tundra. The 

 latter again, according to the predominance of one or the other type of 

 lichen, exhibits a different facies, corresponding to the varying climatic condi- 

 tions, and we have Cladonia- tundra (Cladonia rangiferina and other species, 

 Sphaerophoron corallioides), Platysma- tundra (Platysma cucullatum and 

 other species, Cetraria islandica and other species), Alectoria-heatJi (species 

 of Alectoria). 



In the less cold tundra-districts more soil is occupied by vegetation than 

 unoccupied ; even wide tracts can have a continuous carpet of lichens. Where 

 the climate is most rigorous the vegetation forms only widely separated 

 patches on the bare, usually stony soil, and we have Rock-tundra 1 . 



Shallow depressions of the tundra, where the water of melted snow and 



1 Warming's Felsenflur und Fjeld-formation. 



