According to Schimper 4 climatic formations. 
Ist, The Arctic-Alpine Formation. 
2nd, The Woodland Formation. 
3rd, The Grassland Formation. 
(Prairie) 
( Plains ) 
4th, The Desert Formation. 
2. Edaphic Formations. 
Controlling factors. 
__ Influence of soil or ground. 
Open edaphic formations. 
Close edaphic formations. 
3. Aquatic Formations. 
Fresh water, or limnetic formations. 
Marine, or pelagic formations. 
4. Culture Formations. 
Vegetation of cultivated fields. 
Vegetation of waste places. 
5. Principal and Individual Formations, etc. 
The principal formations. 
Plant societies. 
The individual formations. 
The factors. 
1. Physical, which relate to variation. 
a. In ground water. 
| b. In physical and chemical condition soil. 
2. Biological, which relate to struggle between species. 
Result is, distinct groups of vegetation elements are formed in 
a society (or principal formation). 
Such a group a formation. 
Compare association, guild. 
Pieces of mosaic, or zones. Typha formation (or typhetum), 
etc. 
Single formations, and mixed formations. 
Facies. 
Vegetation forms. 
Layers. 
Zones. 
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